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Lv L, Guo W, Guan W, Chen Y, Huang R, Yuan Z, Pu Q, Feng S, Zheng X, Li Y, Xiao L, Zhao H, Qi X, Cai D. Echocardiographic assessment of Xenopus tropicalis heart regeneration. Cell Biosci 2023; 13:29. [PMID: 36782288 PMCID: PMC9926761 DOI: 10.1186/s13578-023-00982-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2022] [Accepted: 02/04/2023] [Indexed: 02/15/2023] Open
Abstract
BACKGROUND Recently, it was reported that the adult X. tropicalis heart can regenerate in a nearly scar-free manner after injury via apical resection. Thus, a cardiac regeneration model in adult X. tropicalis provides a powerful tool for recapitulating a perfect regeneration phenomenon, elucidating the underlying molecular mechanisms of cardiac regeneration in an adult heart, and developing an interventional strategy for the improvement in the regeneration of an adult heart, which may be more applicable in mammals than in species with a lower degree of evolution. However, a noninvasive and rapid real-time method that can observe and measure the long-term dynamic change in the regenerated heart in living organisms to monitor and assess the regeneration and repair status in this model has not yet been established. RESULTS In the present study, the methodology of echocardiographic assessment to characterize the morphology, anatomic structure and cardiac function of injured X. tropicalis hearts established by apex resection was established. The findings of this study demonstrated for the first time that small animal echocardiographic analysis can be used to assess the regeneration of X. tropicalis damaged heart in a scar-free perfect regeneration or nonperfect regeneration with adhesion manner via recovery of morphology and cardiac function. CONCLUSIONS Small animal echocardiography is a reliable, noninvasive and rapid real-time method for observing and assessing the long-term dynamic changes in the regeneration of injured X. tropicalis hearts.
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Affiliation(s)
- Luocheng Lv
- grid.258164.c0000 0004 1790 3548Key Laboratory of Regenerative Medicine, Ministry of Education, Jinan University, Guangzhou, 510632 People’s Republic of China ,grid.258164.c0000 0004 1790 3548Joint Laboratory for Regenerative Medicine, Chinese University of Hong Kong-Jinan University, Guangzhou, 510632 China ,grid.258164.c0000 0004 1790 3548International Base of Collaboration for Science and Technology (JNU), Ministry of Science and Technology, Guangzhou, 510632 Guangdong China ,grid.258164.c0000 0004 1790 3548Department of Developmental and Regenerative Biology, Jinan University, Guangzhou, 510632 China
| | - Weimin Guo
- grid.258164.c0000 0004 1790 3548Key Laboratory of Regenerative Medicine, Ministry of Education, Jinan University, Guangzhou, 510632 People’s Republic of China ,grid.258164.c0000 0004 1790 3548Joint Laboratory for Regenerative Medicine, Chinese University of Hong Kong-Jinan University, Guangzhou, 510632 China ,grid.258164.c0000 0004 1790 3548International Base of Collaboration for Science and Technology (JNU), Ministry of Science and Technology, Guangzhou, 510632 Guangdong China ,grid.258164.c0000 0004 1790 3548Department of Developmental and Regenerative Biology, Jinan University, Guangzhou, 510632 China
| | - Wei Guan
- grid.258164.c0000 0004 1790 3548Key Laboratory of Regenerative Medicine, Ministry of Education, Jinan University, Guangzhou, 510632 People’s Republic of China ,grid.258164.c0000 0004 1790 3548Joint Laboratory for Regenerative Medicine, Chinese University of Hong Kong-Jinan University, Guangzhou, 510632 China ,grid.258164.c0000 0004 1790 3548International Base of Collaboration for Science and Technology (JNU), Ministry of Science and Technology, Guangzhou, 510632 Guangdong China ,grid.258164.c0000 0004 1790 3548Department of Developmental and Regenerative Biology, Jinan University, Guangzhou, 510632 China
| | - Yilin Chen
- grid.258164.c0000 0004 1790 3548Key Laboratory of Regenerative Medicine, Ministry of Education, Jinan University, Guangzhou, 510632 People’s Republic of China ,grid.258164.c0000 0004 1790 3548Joint Laboratory for Regenerative Medicine, Chinese University of Hong Kong-Jinan University, Guangzhou, 510632 China ,grid.258164.c0000 0004 1790 3548International Base of Collaboration for Science and Technology (JNU), Ministry of Science and Technology, Guangzhou, 510632 Guangdong China ,grid.258164.c0000 0004 1790 3548Department of Developmental and Regenerative Biology, Jinan University, Guangzhou, 510632 China
| | - Ruijin Huang
- grid.10388.320000 0001 2240 3300Institute of Anatomy, Department of Neuroanatomy, Medical Faculty, University of Bonn, Bonn, Germany
| | - Ziqiang Yuan
- grid.430387.b0000 0004 1936 8796Cancer Institute of New Jersey, Department of Medical Oncology, Robert Wood Johnson of Medical School, New Brunswick, USA
| | - Qin Pu
- grid.10388.320000 0001 2240 3300Institute of Anatomy, Department of Neuroanatomy, Medical Faculty, University of Bonn, Bonn, Germany
| | - Shanshan Feng
- grid.258164.c0000 0004 1790 3548Key Laboratory of Regenerative Medicine, Ministry of Education, Jinan University, Guangzhou, 510632 People’s Republic of China ,grid.258164.c0000 0004 1790 3548Joint Laboratory for Regenerative Medicine, Chinese University of Hong Kong-Jinan University, Guangzhou, 510632 China ,grid.258164.c0000 0004 1790 3548International Base of Collaboration for Science and Technology (JNU), Ministry of Science and Technology, Guangzhou, 510632 Guangdong China ,grid.258164.c0000 0004 1790 3548Department of Developmental and Regenerative Biology, Jinan University, Guangzhou, 510632 China
| | - Xin Zheng
- grid.258164.c0000 0004 1790 3548Key Laboratory of Regenerative Medicine, Ministry of Education, Jinan University, Guangzhou, 510632 People’s Republic of China ,grid.258164.c0000 0004 1790 3548Joint Laboratory for Regenerative Medicine, Chinese University of Hong Kong-Jinan University, Guangzhou, 510632 China ,grid.258164.c0000 0004 1790 3548International Base of Collaboration for Science and Technology (JNU), Ministry of Science and Technology, Guangzhou, 510632 Guangdong China ,grid.258164.c0000 0004 1790 3548Department of Developmental and Regenerative Biology, Jinan University, Guangzhou, 510632 China
| | - Yanmei Li
- grid.258164.c0000 0004 1790 3548Key Laboratory of Regenerative Medicine, Ministry of Education, Jinan University, Guangzhou, 510632 People’s Republic of China ,grid.258164.c0000 0004 1790 3548Joint Laboratory for Regenerative Medicine, Chinese University of Hong Kong-Jinan University, Guangzhou, 510632 China ,grid.258164.c0000 0004 1790 3548International Base of Collaboration for Science and Technology (JNU), Ministry of Science and Technology, Guangzhou, 510632 Guangdong China ,grid.258164.c0000 0004 1790 3548Department of Developmental and Regenerative Biology, Jinan University, Guangzhou, 510632 China
| | - Luanjuan Xiao
- grid.258164.c0000 0004 1790 3548Key Laboratory of Regenerative Medicine, Ministry of Education, Jinan University, Guangzhou, 510632 People’s Republic of China ,grid.258164.c0000 0004 1790 3548Joint Laboratory for Regenerative Medicine, Chinese University of Hong Kong-Jinan University, Guangzhou, 510632 China ,grid.258164.c0000 0004 1790 3548International Base of Collaboration for Science and Technology (JNU), Ministry of Science and Technology, Guangzhou, 510632 Guangdong China ,grid.258164.c0000 0004 1790 3548Department of Developmental and Regenerative Biology, Jinan University, Guangzhou, 510632 China
| | - Hui Zhao
- Stem Cell and Regeneration TRP, School of Biomedical Sciences, The Chinese University of Hong Kong, Shatin, Hong Kong, China.
| | - Xufeng Qi
- Key Laboratory of Regenerative Medicine, Ministry of Education, Jinan University, Guangzhou, 510632, People's Republic of China. .,Joint Laboratory for Regenerative Medicine, Chinese University of Hong Kong-Jinan University, Guangzhou, 510632, China. .,International Base of Collaboration for Science and Technology (JNU), Ministry of Science and Technology, Guangzhou, 510632, Guangdong, China. .,Department of Developmental and Regenerative Biology, Jinan University, Guangzhou, 510632, China.
| | - Dongqing Cai
- Key Laboratory of Regenerative Medicine, Ministry of Education, Jinan University, Guangzhou, 510632, People's Republic of China. .,Joint Laboratory for Regenerative Medicine, Chinese University of Hong Kong-Jinan University, Guangzhou, 510632, China. .,International Base of Collaboration for Science and Technology (JNU), Ministry of Science and Technology, Guangzhou, 510632, Guangdong, China. .,Department of Developmental and Regenerative Biology, Jinan University, Guangzhou, 510632, China.
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Soepriatna AH, Damen FW, Vlachos PP, Goergen CJ. Cardiac and respiratory-gated volumetric murine ultrasound. Int J Cardiovasc Imaging 2017; 34:713-724. [PMID: 29234935 DOI: 10.1007/s10554-017-1283-z] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/28/2017] [Accepted: 11/22/2017] [Indexed: 01/13/2023]
Abstract
Current cardiovascular ultrasound mainly employs planar imaging techniques to assess function and physiology. These techniques rely on geometric assumptions, which are dependent on the imaging plane, susceptible to inter-observer variability, and may be inaccurate when studying complex diseases. Here, we developed a gated volumetric murine ultrasound technique to visualize cardiovascular motion with high spatiotemporal resolution and directly evaluate cardiovascular health. Cardiac and respiratory-gated cine loops, acquired at 1000 frames-per-second from sequential positions, were temporally registered to generate a four-dimensional (4D) dataset. We applied this technique to (1) evaluate left ventricular (LV) function from both healthy mice and mice with myocardial infarction and (2) characterize aortic wall strain of angiotensin II-induced dissecting abdominal aortic aneurysms in apolipoprotein E-deficient mice. Combined imaging and processing times for the 4D technique was approximately 2-4 times longer than conventional 2D approaches, but substantially more data is collected with 4D ultrasound and further optimization can be implemented to reduce imaging times. Direct volumetric measurements of 4D cardiac data aligned closely with those obtained from MRI, contrary to conventional methods, which were sensitive to transducer alignment, leading to overestimation or underestimation of estimated LV parameters in infarcted hearts. Green-Lagrange circumferential strain analysis revealed higher strain values proximal and distal to the aneurysm than within the aneurysmal region, consistent with published reports. By eliminating the need for geometrical assumptions, the presented 4D technique can be used to more accurately evaluate cardiac function and aortic pulsatility. Furthermore, this technique allows for the visualization of regional differences that may be overlooked with conventional 2D approaches.
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Affiliation(s)
- Arvin H Soepriatna
- Weldon School of Biomedical Engineering, Purdue University, 206 S. Martin Jischke Drive, West Lafayette, IN, 47907, USA
| | - Frederick W Damen
- Weldon School of Biomedical Engineering, Purdue University, 206 S. Martin Jischke Drive, West Lafayette, IN, 47907, USA
| | - Pavlos P Vlachos
- Weldon School of Biomedical Engineering, Purdue University, 206 S. Martin Jischke Drive, West Lafayette, IN, 47907, USA.,School of Mechanical Engineering, Purdue University, 585 Purdue Mall, West Lafayette, IN, 47907, USA
| | - Craig J Goergen
- Weldon School of Biomedical Engineering, Purdue University, 206 S. Martin Jischke Drive, West Lafayette, IN, 47907, USA.
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Feng Y, Chai J, Chu W, Ma L, Zhang P, Duan H. Combination of ketamine and xylazine exacerbates cardiac dysfunction in severely scalded rats during the shock stage. Exp Ther Med 2013; 6:641-648. [PMID: 24137240 PMCID: PMC3786838 DOI: 10.3892/etm.2013.1213] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2013] [Accepted: 05/23/2013] [Indexed: 11/06/2022] Open
Abstract
Cardiac inhibition due to burn injury and anesthetics have been documented previously. However, little is known about their combined effects on cardiac function. The aim of the present study was to observe the effects of a ketamine/xylazine (K/X) combination on the cardiac function of rats with severe scalds and compare them with those of avertin. Adult rats were randomly distributed into four groups: the KXB group (scalds anesthetized with K/X, n=10), the KXC group (sham scalds anesthetized with K/X, n=10), the AVB group (scalds anesthetized with avertin, n=10) and the AVC group (sham scalds anesthetized with avertin, n=10). Ketamine and xylazine were administered at 25 and 6 mg/kg, respectively, and avertin at 200 mg/kg before full-thickness scalds or sham scalds of 30% total body surface area (TBSA) were produced. Echocardiographic parameters were assessed following injury. The heart rate (HR) in the KXB group was fatally low during the study period. Fractional shortening (FS%) and ejection fraction (EF) in the KXB group were extremely low initially and remained low. The left ventricular end-diastolic volume (LVEDV) and left ventricular end-systolic volume (LVESV) were reduced in the burned rats. Serum levels of cardiac troponin I (cTnI) were significantly higher in the KXB group than in the AVB group (1.66±0.28 vs. 1.16±0.34 ng/ml, P<0.01). The highest lung wet/dry weight ratio was observed in the KXB group. However, no evident heart tissue pathological changes were observed in these groups. The apoptotic index of myocardial cells and caspase 3 expression level were highest in the KXB group (P<0.01). In conclusion, K/X exacerbated cardiac inhibition in severely scalded rats during the shock stage by a mechanism which may involve mitochondrial apoptosis.
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Affiliation(s)
- Yongqiang Feng
- Department of Burns and Plastic Surgery, The First Affiliated Hospital of Chinese PLA General Hospital, Beijing 100048, P.R. China
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Montano MM, Desjardins CL, Doughman YQ, Hsieh YH, Hu Y, Bensinger HM, Wang C, Stelzer JE, Dick TE, Hoit BD, Chandler MP, Yu X, Watanabe M. Inducible re-expression of HEXIM1 causes physiological cardiac hypertrophy in the adult mouse. Cardiovasc Res 2013; 99:74-82. [PMID: 23585471 PMCID: PMC3687752 DOI: 10.1093/cvr/cvt086] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/15/2012] [Revised: 03/28/2013] [Accepted: 04/01/2013] [Indexed: 01/06/2023] Open
Abstract
AIMS The transcription factor hexamethylene-bis-acetamide-inducible protein 1 (HEXIM1) regulates myocardial vascularization and growth during cardiogenesis. Our aim was to determine whether HEXIM1 also has a beneficial role in modulating vascularization, myocardial growth, and function within the adult heart. METHODS AND RESULTS To achieve our objective, we created and investigated a mouse line wherein HEXIM1 was re-expressed in adult cardiomyocytes to levels found in the foetal heart. Our findings support a beneficial role for HEXIM1 through increased vascularization, myocardial growth, and increased ejection fraction within the adult heart. HEXIM1 re-expression induces angiogenesis, that is, essential for physiological hypertrophy and maintenance of cardiac function. The ability of HEXIM1 to co-ordinate processes associated with physiological hypertrophy may be attributed to HEXIM1 regulation of other transcription factors (HIF-1-α, c-Myc, GATA4, and PPAR-α) that, in turn, control many genes involved in myocardial vascularization, growth, and metabolism. Moreover, the mechanism for HEXIM1-induced physiological hypertrophy appears to be distinct from that involving the PI3K/AKT pathway. CONCLUSION HEXIM1 re-expression results in the induction of angiogenesis that allows for the co-ordination of tissue growth and angiogenesis during physiological hypertrophy.
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Affiliation(s)
- Monica M. Montano
- Department of Pharmacology, Case Western Reserve University School of Medicine, H.G. Wood Bldg. W307, 2109 Adelbert Road, Cleveland, OH 44106, USA
| | - Candida L. Desjardins
- Department of Biomedical Engineering, Case Western Reserve University School of Engineering, Cleveland, OH 44106, USA
| | - Yong Qui Doughman
- Department of Pediatrics, Case Western Reserve University School of Medicine, Rainbow Babies and Children's Hospital, 11100 Euclid Avenue, Cleveland, OH 44106, USA
- Department of Genetics, Case Western Reserve University School of Medicine, Rainbow Babies and Children's Hospital, 11100 Euclid Avenue, Cleveland, OH 44106, USA
- Department of Anatomy, Case Western Reserve University School of Medicine, Rainbow Babies and Children's Hospital, 11100 Euclid Avenue, Cleveland, OH 44106, USA
| | - Yee-Hsee Hsieh
- Department of Medicine, Case Western Reserve University School of Medicine, Cleveland, OH 44106, USA
| | - Yanduan Hu
- Department of Pharmacology, Case Western Reserve University School of Medicine, H.G. Wood Bldg. W307, 2109 Adelbert Road, Cleveland, OH 44106, USA
| | - Heather M. Bensinger
- Department of Pharmacology, Case Western Reserve University School of Medicine, H.G. Wood Bldg. W307, 2109 Adelbert Road, Cleveland, OH 44106, USA
| | - Connie Wang
- Department of Pediatrics, Case Western Reserve University School of Medicine, Rainbow Babies and Children's Hospital, 11100 Euclid Avenue, Cleveland, OH 44106, USA
- Department of Genetics, Case Western Reserve University School of Medicine, Rainbow Babies and Children's Hospital, 11100 Euclid Avenue, Cleveland, OH 44106, USA
- Department of Anatomy, Case Western Reserve University School of Medicine, Rainbow Babies and Children's Hospital, 11100 Euclid Avenue, Cleveland, OH 44106, USA
| | - Julian E. Stelzer
- Department of Physiology, Case Western Reserve University School of Medicine, Cleveland, OH 44106, USA
| | - Thomas E. Dick
- Department of Medicine, Case Western Reserve University School of Medicine, Cleveland, OH 44106, USA
| | - Brian D. Hoit
- Department of Medicine, Case Western Reserve University School of Medicine, Cleveland, OH 44106, USA
| | - Margaret P. Chandler
- Department of Physiology, Case Western Reserve University School of Medicine, Cleveland, OH 44106, USA
| | - Xin Yu
- Department of Biomedical Engineering, Case Western Reserve University School of Engineering, Cleveland, OH 44106, USA
| | - Michiko Watanabe
- Department of Pediatrics, Case Western Reserve University School of Medicine, Rainbow Babies and Children's Hospital, 11100 Euclid Avenue, Cleveland, OH 44106, USA
- Department of Genetics, Case Western Reserve University School of Medicine, Rainbow Babies and Children's Hospital, 11100 Euclid Avenue, Cleveland, OH 44106, USA
- Department of Anatomy, Case Western Reserve University School of Medicine, Rainbow Babies and Children's Hospital, 11100 Euclid Avenue, Cleveland, OH 44106, USA
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Christia P, Bujak M, Gonzalez-Quesada C, Chen W, Dobaczewski M, Reddy A, Frangogiannis NG. Systematic characterization of myocardial inflammation, repair, and remodeling in a mouse model of reperfused myocardial infarction. J Histochem Cytochem 2013; 61:555-70. [PMID: 23714783 DOI: 10.1369/0022155413493912] [Citation(s) in RCA: 82] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Mouse models of myocardial infarction are essential tools for the study of cardiac injury, repair, and remodeling. Our current investigation establishes a systematic approach for quantitative evaluation of the inflammatory and reparative response, cardiac function, and geometry in a mouse model of reperfused myocardial infarction. Reperfused mouse infarcts exhibited marked induction of inflammatory cytokines that peaked after 6 hr of reperfusion. In the infarcted heart, scar contraction and chamber dilation continued for at least 28 days after reperfusion; infarct maturation was associated with marked thinning of the scar, accompanied by volume loss and rapid clearance of cellular elements. Echocardiographic measurements of end-diastolic dimensions correlated well with morphometric assessment of dilative remodeling in perfusion-fixed hearts. Hemodynamic monitoring was used to quantitatively assess systolic and diastolic function; the severity of diastolic dysfunction following myocardial infarction correlated with cardiomyocyte hypertrophy and infarct collagen content. Expression of molecular mediators of inflammation and cellular infiltration needs to be investigated during the first 72 hr, whereas assessment of dilative remodeling requires measurement of geometric parameters for at least four weeks after the acute event. Rapid initiation and resolution of the inflammatory response, accelerated scar maturation, and extensive infarct volume loss are important characteristics of infarct healing in mice.
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Affiliation(s)
- Panagiota Christia
- Wilf Family Cardiovascular Research Institute, Department of Medicine, Division of Cardiology, Albert Einstein College of Medicine, Bronx, NY 10461, USA
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Akki A, Gupta A, Weiss RG. Magnetic resonance imaging and spectroscopy of the murine cardiovascular system. Am J Physiol Heart Circ Physiol 2013; 304:H633-48. [PMID: 23292717 DOI: 10.1152/ajpheart.00771.2011] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Magnetic resonance imaging (MRI) has emerged as a powerful and reliable tool to noninvasively study the cardiovascular system in clinical practice. Because transgenic mouse models have assumed a critical role in cardiovascular research, technological advances in MRI have been extended to mice over the last decade. These have provided critical insights into cardiac and vascular morphology, function, and physiology/pathophysiology in many murine models of heart disease. Furthermore, magnetic resonance spectroscopy (MRS) has allowed the nondestructive study of myocardial metabolism in both isolated hearts and in intact mice. This article reviews the current techniques and important pathophysiological insights from the application of MRI/MRS technology to murine models of cardiovascular disease.
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Affiliation(s)
- Ashwin Akki
- Division of Cardiology, Department of Medicine, and Division of Magnetic Resonance Research, Department of Radiology, The Johns Hopkins University, School of Medicine, Baltimore, MD, USA
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Constantinides C, Angeli S, Kossivas F, Ktorides P. Underestimation of Murine Cardiac Hemodynamics Using Invasive Catheters: Errors, Limitations, and Remedies. Cardiovasc Eng Technol 2012. [DOI: 10.1007/s13239-012-0084-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
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Abstract
BACKGROUND Venous thrombosis (VT) is an important cause of morbidity and mortality in clinical medicine. Animal models studying venous thrombosis are scarce and, in most cases, very crude and rely on sacrificing the animals to excise formed thrombi. Developing an in vivo murine model of venous thrombosis can be a powerful tool for studying venous thrombosis. OBJECTIVES We sought to use a high-frequency ultrasound system (HFUS) to dynamically and non-invasively monitor thrombus formation in the inferior vena cava (IVC) of mice. METHODS We developed a murine model of venous thrombosis using, for detection, the Vevo 770(®), a micro-imaging HFUS. Two different thrombosis models were used to generate thrombi in the IVC of C57Bl/6NCr mice: (i) ligation and (ii) application of ferric chloride (FeCl(3)). We then assessed venous thrombosis by HFUS. RESULTS In both models, measurements of the clot pathologically correlated favorably with measurements acquired with HFUS. Thrombus develops less than an hour after ligation or FeCl(3) -induced injury of the IVC and the size of the clot increases over time for up to 24 h. Importantly, we demonstrate that HFUS can be used to monitor the effect of an anticoagulant such as dalteparin until complete resolution of the thrombus. CONCLUSIONS These data show that HFUS assesses venous thrombosis in mice reliably and non-invasively. Developing a murine model of thrombosis using more accurate, and clinically more relevant, techniques such as ultrasonography, is a step towards a better understanding of the pathophysiology of venous thromboembolism.
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Affiliation(s)
- M N Aghourian
- Lady Davis Institute for Medical Research, Sir Mortimer B. Davis-Jewish General Hospital, Montreal, Quebec, Canada
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9
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Constantinides C, Angeli SI, Mean RJ. Murine cardiac catheterizations and hemodynamics: on the issue of parallel conductance. IEEE Trans Biomed Eng 2011; 58:3260-8. [PMID: 21900070 DOI: 10.1109/tbme.2011.2167147] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Catheter-based measurements are extensively used nowadays in animal models to quantify global left ventricular (LV) cardiac function and hemodynamics. Conductance catheter measurements yield estimates of LV volumes. Such estimates, however, are confounded by the catheter's nonhomogeneous emission field and the contribution to the total conductance of surrounding tissue or blood conductance values (other than LV blood), a term often known as parallel conductance. In practice, in most studies, volume estimates are based on the assumptions that the catheter's electric field is homogeneous and that parallel conductance is constant, despite prior results showing that these assumptions are incorrect. This study challenges the assumption for spatial homogeneity of electric field excitation of miniature catheters and investigated the electric field distribution of miniature catheters in the murine heart, based on cardiac model-driven (geometric, lump component) simulations and noninvasive imaging, at both systolic and diastolic cardiac phases. Results confirm the nonuniform catheter emission field, confined spatially within the LV cavity and myocardium, falling to 10% of its peak value at the ring electrode surface, within 1.1-2.0 mm, given a relative tissue permittivity of 33,615. Additionally, <1% of power leaks were observed into surrounding cavities or organs at end-diastole. Temporally varying parallel conductance effects are also confirmed, becoming more prominent at end-systole.
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Price AN, Cheung KK, Lim SY, Yellon DM, Hausenloy DJ, Lythgoe MF. Rapid assessment of myocardial infarct size in rodents using multi-slice inversion recovery late gadolinium enhancement CMR at 9.4T. J Cardiovasc Magn Reson 2011; 13:44. [PMID: 21892953 PMCID: PMC3182945 DOI: 10.1186/1532-429x-13-44] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2011] [Accepted: 09/05/2011] [Indexed: 01/29/2023] Open
Abstract
BACKGROUND Myocardial infarction (MI) can be readily assessed using late gadolinium enhancement (LGE) cardiovascular magnetic resonance (CMR). Inversion recovery (IR) sequences provide the highest contrast between enhanced infarct areas and healthy myocardium. Applying such methods to small animals is challenging due to rapid respiratory and cardiac rates relative to T1 relaxation. METHODS Here we present a fast and robust protocol for assessing LGE in small animals using a multi-slice IR gradient echo sequence for efficient assessment of LGE. An additional Look-Locker sequence was used to assess the optimum inversion point on an individual basis and to determine most appropriate gating points for both rat and mouse. The technique was applied to two preclinical scenarios: i) an acute (2 hour) reperfused model of MI in rats and ii) mice 2 days following non-reperfused MI. RESULTS LGE images from all animals revealed clear areas of enhancement allowing for easy volume segmentation. Typical inversion times required to null healthy myocardium in rats were between 300-450 ms equivalent to 2-3 R-waves and ~330 ms in mice, typically 3 R-waves following inversion. Data from rats was also validated against triphenyltetrazolium chloride staining and revealed close agreement for infarct size. CONCLUSION The LGE protocol presented provides a reliable method for acquiring images of high contrast and quality without excessive scan times, enabling higher throughput in experimental studies requiring reliable assessment of MI.
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Affiliation(s)
- Anthony N Price
- UCL Centre for Advanced Biomedical Imaging, Department of Medicine and UCL Institute of Child Health, University College London, UK
| | - King K Cheung
- UCL Centre for Advanced Biomedical Imaging, Department of Medicine and UCL Institute of Child Health, University College London, UK
| | - Shiang Y Lim
- The Hatter Cardiovascular Institute, University College London Hospital and Medical School, London, UK
| | - Derek M Yellon
- The Hatter Cardiovascular Institute, University College London Hospital and Medical School, London, UK
| | - Derek J Hausenloy
- The Hatter Cardiovascular Institute, University College London Hospital and Medical School, London, UK
| | - Mark F Lythgoe
- UCL Centre for Advanced Biomedical Imaging, Department of Medicine and UCL Institute of Child Health, University College London, UK
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11
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Ram R, Mickelsen DM, Theodoropoulos C, Blaxall BC. New approaches in small animal echocardiography: imaging the sounds of silence. Am J Physiol Heart Circ Physiol 2011; 301:H1765-80. [PMID: 21873501 DOI: 10.1152/ajpheart.00559.2011] [Citation(s) in RCA: 101] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Systolic and diastolic dysfunction of the left ventricle (LV) is a hallmark of most cardiac diseases. In vivo assessment of heart function in animal models, particularly mice, is essential to refining our understanding of cardiovascular disease processes. Ultrasound echocardiography has emerged as a powerful, noninvasive tool to serially monitor cardiac performance and map the progression of heart dysfunction in murine injury models. This review covers current applications of small animal echocardiography, as well as emerging technologies that improve evaluation of LV function. In particular, we describe speckle-tracking imaging-based regional LV analysis, a recent advancement in murine echocardiography with proven clinical utility. This sensitive measure enables an early detection of subtle myocardial defects before global dysfunction in genetically engineered and rodent surgical injury models. Novel visualization technologies that allow in-depth phenotypic assessment of small animal models, including perfusion imaging and fetal echocardiography, are also discussed. As imaging capabilities continue to improve, murine echocardiography will remain a critical component of the investigator's armamentarium in translating animal data to enhanced clinical treatment of cardiovascular diseases.
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Affiliation(s)
- Rashmi Ram
- Aab Cardiovascular Research Institute and Department of Medicine, University of Rochester Medical Center, Rochester, NY 14642, USA
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12
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Constantinides C, Angeli S, Mean R. Murine cardiac hemodynamics following manganese administration under isoflurane anesthesia. Ann Biomed Eng 2011; 39:2706-20. [PMID: 21818535 DOI: 10.1007/s10439-011-0367-5] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2011] [Accepted: 07/21/2011] [Indexed: 12/22/2022]
Abstract
This study examines (a) the temporal stability of hemodynamic indices of systolic and diastolic function in C57BL/6 mice under 1.5% isoflurane (ISO) (v/v) anesthesia conditions in 50:50 O(2)/N(2)O (v/v) within 90 min post-induction, and (b) the effects of Mn(2+) on the mouse hemodynamic response in male C57BL/6 mice (n = 16). Left ventricular catheterizations allowed estimation of the hemodynamic indices. Hypertonic saline infusion (10%) allowed absolute volume quantification in conjunction with a separate series of aortic flow experiments (n = 3). In a separate cohort of mice (n = 6), MnCl(2) (190 nmoles/g/bw) was infused via the left jugular for 29-39 min, following 11 min of baseline recording, to assess temporal responses. Stable temporal hemodynamic responses were achieved in control mice under ISO anesthesia. Hemodynamic indices during control, time-matched-control, baseline-Mn, and Mn-infused periods, were within normal expected ranges. No chronotropic changes were observed. Significant differences in systolic and diastolic cardiac indices of function (HR, EF, ESP, dP/dt (max), dP/dt (min), PAMP, τ(glantz), and τ(weiss)) resulted between baseline-Mn and Mn-infused time periods in Mn-treated mice at the 1% significance (p < 0.001). Transient positive, or negative, or positive followed by negative evoked pressure-volume loop shifts were observed (exemplified through changes in the end-systolic pressure-volume relationship and dP/dt (max)) in Mn-infusion studies. It is concluded that Mn(2+) can be used safely for prolonged mouse imaging studies, however, the significant variations elicited in cardiovascular hemodynamics post-manganese infusion, necessitate further investigations for its suitability and appropriateness for quantification of global cardiac function in image-based phenotyping.
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Affiliation(s)
- C Constantinides
- Laboratory of Physiology and Biomedical Imaging, Department of Mechanical and Manufacturing Engineering, School of Engineering, University of Cyprus, Nicosia, Cyprus.
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13
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Badea CT, Hedlund LW, Qi Y, Berridge B, Johnson GA. In vivo imaging of rat coronary arteries using bi-plane digital subtraction angiography. J Pharmacol Toxicol Methods 2011; 64:151-7. [PMID: 21683146 DOI: 10.1016/j.vascn.2011.05.008] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2010] [Revised: 04/19/2011] [Accepted: 05/31/2011] [Indexed: 12/14/2022]
Abstract
INTRODUCTION X-ray based digital subtraction angiography (DSA) is a common clinical imaging method for vascular morphology and function. Coronary artery characterization is one of its most important applications. We show that bi-plane DSA of rat coronary arteries can provide a powerful imaging tool for translational safety assessment in drug discovery. METHODS A novel, dual tube/detector system, constructed explicitly for preclinical imaging, supports image acquisition at 10 frames/s with 88-micron spatial resolution. Ventilation, x-ray exposure, and contrast injection are all precisely synchronized using a biological sequence controller implemented as a LabVIEW application. A set of experiments were performed to test and optimize the sampling and image quality. We applied the DSA imaging protocol to record changes in the visualization of coronaries and myocardial perfusion induced by a vasodilator drug, nitroprusside. The drug was infused into a tail vein catheter using a peristaltic infusion pump at a rate of 0.07 mL/h for 3 min (dose: 0.0875 mg). Multiple DSA sequences were acquired before, during, and up to 25 min after drug infusion. Perfusion maps of the heart were generated in MATLAB to compare the drug effects over time. RESULTS The best trade-off between the injection time, pressure, and image quality was achieved at 60 PSI, with the injection of 150 ms occurring early in diastole (60 ms delay) and resulting in the delivery of 113 μL of contrast agent. DSA images clearly show the main branches of the coronary arteries in an intact, beating heart. The drug test demonstrated that DSA can detect relative changes in coronary circulation via perfusion maps. CONCLUSIONS The methodology for DSA imaging of rat coronary arteries can serve as a template for future translational studies to assist in safety evaluation of new pharmaceuticals. Although x-ray imaging involves radiation, the associated dose (0.4 Gy) is not a major limitation.
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Affiliation(s)
- Cristian T Badea
- Center for In Vivo Microscopy, Duke University Medical Center, Durham, NC 27710, USA.
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14
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Souza APD, Jelicks LA, Tanowitz HB, Olivieri BP, Medeiros MM, Oliveira GM, Pires ARC, Santos AMD, Araújo-Jorge TC. The benefits of using selenium in the treatment of Chagas disease: prevention of right ventricle chamber dilatation and reversion of Trypanosoma cruzi-induced acute and chronic cardiomyopathy in mice. Mem Inst Oswaldo Cruz 2011; 105:746-51. [PMID: 20944987 DOI: 10.1590/s0074-02762010000600003] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2010] [Accepted: 07/20/2010] [Indexed: 01/14/2023] Open
Abstract
Cardiac damage is a frequent manifestation of Chagas disease, which is caused by the parasite Trypanosoma cruzi. Selenium (Se) is an essential micronutrient, the deficiency of which has been implicated in the development of cardiomyopathy. Our group has previously demonstrated that Se supplementation prevents myocardial damage during acute T. cruzi infection in mice. In this study, we analyzed the effect of Se treatment in cases of T. cruzi infection using prevention and reversion schemes. In the Se prevention scheme, mice were given Se supplements (2 ppm) starting two weeks prior to inoculation with T. cruzi(Brazil strain) and continuing until 120 days post-infection (dpi). In the Se reversion scheme, mice were treated with Se (4 ppm) for 100 days, starting at 160 dpi. Dilatation of the right ventricle was observed in the infected control group at both phases of T. cruzi infection, but it was not observed in the infected group that received Se treatment. Surviving infected mice that were submitted to the Se reversion scheme presented normal P wave values and reduced inflammation of the pericardium. These data indicate that Se treatment prevents right ventricular chamber increase and thus can be proposed as an adjuvant therapy for cardiac alterations already established by T. cruzi infection.
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Affiliation(s)
- Andréa P de Souza
- Laboratório de Inovações em Terapias, Ensino e Bioprodutos, Instituto Oswaldo Cruz-Fiocruz, Av. Brasil 4365, Rio de Janeiro, RJ, Brazil
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15
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Coolen BF, Geelen T, Paulis LEM, Nauerth A, Nicolay K, Strijkers GJ. Three-dimensional T1 mapping of the mouse heart using variable flip angle steady-state MR imaging. NMR IN BIOMEDICINE 2011; 24:154-162. [PMID: 20960583 DOI: 10.1002/nbm.1566] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/25/2009] [Revised: 04/20/2010] [Accepted: 04/20/2010] [Indexed: 05/28/2023]
Abstract
Cardiac MR T(1) mapping is a promising quantitative imaging tool for the diagnosis and evaluation of cardiomyopathy. Here, we present a new preclinical cardiac MRI method enabling three-dimensional T(1) mapping of the mouse heart. The method is based on a variable flip angle analysis of steady-state MR imaging data. A retrospectively triggered three-dimensional FLASH (fast low-angle shot) sequence (3D IntraGate) enables a constant repetition time and maintains steady-state conditions. 3D T(1) mapping of the complete mouse heart could be achieved in 20 min. High-quality, bright-blood T(1) maps were obtained with homogeneous T(1) values (1764 ± 172 ms) throughout the myocardium. The repeatability coefficient of R(1) (1/T(1) ) in a specific region of the mouse heart was between 0.14 and 0.20 s(-1) , depending on the number of flip angles. The feasibility for detecting regional differences in ΔR(1) was shown with pre- and post-contrast T(1) mapping in mice with surgically induced myocardial infarction, for which ΔR(1) values up to 0.83 s(-1) were found in the infarct zone. The sequence was also investigated in black-blood mode, which, interestingly, showed a strong decrease in the apparent mean T(1) of healthy myocardium (905 ± 110 ms). This study shows that 3D T(1) mapping in the mouse heart is feasible and can be used to monitor regional changes in myocardial T(1), particularly in relation to pathology and in contrast-enhanced experiments to estimate local concentrations of (targeted) contrast agent.
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Affiliation(s)
- Bram F Coolen
- Biomedical NMR, Department of Biomedical Engineering, Eindhoven University of Technology, Eindhoven, the Netherlands
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16
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Asemu G, Fishbein K, Lao QZ, Ravindran A, Herbert R, Canuto HC, Spencer RG, Soldatov NM. Cardiac phenotype induced by a dysfunctional α 1C transgene: a general problem for the transgenic approach. Channels (Austin) 2011; 5:138-47. [PMID: 21224729 DOI: 10.4161/chan.5.2.14314] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Based on stable integration of recombinant DNA into a host genome, transgenic technology has become an important genetic engineering methodology. An organism whose genetic characteristics have been altered by the insertion of foreign DNA is supposed to exhibit a new phenotype associated with the function of the transgene. However, successful insertion may not be sufficient to achieve specific modification of function. In this study we describe a strain of transgenic mouse, G7-882, generated by incorporation into the mouse genome of human CaV 1.2 α(1C) cDNA deprived of 3'-UTR to exclude transcription. We found that, in response to chronic infusion of isoproterenol, G7-882 develops dilated cardiomyopathy, a misleading "transgenic artifact" compatible with the expected function of the incorporated "correct" transgene. Specifically, using magnetic resonance imaging (MRI), we found that chronic β-adrenergic stimulation of G7-882 mice caused left ventricular hypertrophy and aggravated development of dilated cardiomyopathy, although no significant changes in the kinetics, density and voltage dependence of the calcium current were observed in G7-882 cardiomyocytes as compared to cells from wild type mice. This result illustrates the possibility that even when a functional transgene is expressed, an observed change in phenotype may be due to the artifact of "incidental incorporation" leading to misleading conclusions. To exclude this possibility and thus provide a robust tool for exploring biological function, the new transgenic phenotype must be replicated in several independently generated transgenic strains.
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Affiliation(s)
- Girma Asemu
- National Institute on Aging, National Institutes of Health, Baltimore, MD, USA
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17
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Tankersley CG, Peng RD, Bedga D, Gabrielson K, Champion HC. Variation in echocardiographic and cardiac hemodynamic effects of PM and ozone inhalation exposure in strains related to Nppa and Npr1 gene knock-out mice. Inhal Toxicol 2010; 22:695-707. [PMID: 20540624 DOI: 10.3109/08958378.2010.487549] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Elevated levels of ambient co-pollutants are associated with adverse cardiovascular outcomes shown by epidemiology studies. The role of particulate matter (PM) and ozone (O3) as co-pollutants in this association is unclear. We hypothesize that cardiac function following PM and O3 exposure is variably affected by genetic determinants (Nppa and Npr1 genes) and age. Heart function was measured before and after 2 days each of the following exposure sequence; (1) 2-h filtered air (FA) and 3-h carbon black (CB; 0.5 microg/m(3)); (2) 2-h O3 (0.6 ppm) and 3-h FA; (3) 5-h FA; and, (4) 2-h O3 and 3-h CB. Two age groups (5 and 18 months old (mo)) were tested in C57Bl/6J (B6) and 129S1/SvImJ (129) mice using echocardiographic (echo) and in vivo hemodynamic (IVH) measurements. With echo, posterior wall thickness was significantly (P < 0.01) greater in 129 relative to B6 mice at baseline. With CB exposure, young B6 and older 129 mice show significant (P < 0.01) reductions in fractional shortening (FS) compared to FA. With O3 exposure, FS was significantly (P < 0.01) diminished in young 129, which was attributable to significant increases in end-systolic left ventricular diameter. With O3 and CB combined, notable (P < 0.01) declines in heart rate and end-systolic posterior wall thickness occurred in young 129 mice. The IVH measurements showed striking (P < 0.05) compromises in cardiac function after CB and O3 exposure; however, strain differences were undetectable. These results suggest that PM and O3 exposures, alone and combined, lead to different cardiac functional changes, and these unique changes are age-specific and dependent on Nppa and Npr1 genes.
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Affiliation(s)
- Clarke G Tankersley
- Department of Environmental Health Sciences, University of Pittsburgh, Pittsburgh, Pennsylvania, USA.
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18
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Detection of Myocardial Dysfunction During Cancer Chemotherapy with Tissue Doppler Imaging: A Canary in the Coal Mine? J Am Soc Echocardiogr 2009; 22:425-6. [DOI: 10.1016/j.echo.2009.02.010] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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19
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Abstract
Rats and mice are the predominant experimental species in cardiovascular research due to the widespread availability of genetic and transgenic rodent models of heart disease. Phenotyping of these models requires reliable and reproducible methods to noninvasively and serially assess cardiovascular structure and function. However, the small size of rodents has presented a challenge. Many of these challenges have been overcome in recent years due to significant technological advances in echocardiographic capabilities. For example, improved spatial resolution and increased frame rates have allowed more precise and accurate quantification of diminutive structures, myocardial function, and blood flow in mice. Consequently, transthoracic echocardiography (TTE) has emerged as a popular and powerful tool for cardiac phenotypic characterization in rodents. This chapter will focus on the use of TTE in rodents for evaluating (1) left ventricular (LV) chamber dimensions and wall thickness, (2) LV mass, (3) global LV systolic and diastolic function, (4) regional LV systolic function by newly developed tissue Doppler imaging (TDI), and (5) hemodynamic parameters. Reliability of these measurements depends on various factors such as the skill and experience of the sonographer and the image analyzer, the type, depth, and duration of anesthesia, and animal characteristics. These topics will also be discussed.
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Affiliation(s)
- Jing Liu
- Novartis Institutes for BioMedical Research and Novartis Pharmaceutical Corporation, East Hanover, NJ, USA
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20
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A modified rabbit model of reperfused myocardial infarction for cardiac MR imaging research. Int J Cardiovasc Imaging 2008; 25:289-98. [PMID: 19043805 DOI: 10.1007/s10554-008-9393-2] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/26/2008] [Accepted: 11/10/2008] [Indexed: 12/16/2022]
Abstract
We sought to obtain a rabbit myocardial infarction (MI) model for research with cardiac magnetic resonance imaging (cMRI) by overcoming a few technical difficulties. A novel endotracheal method was developed for intubation and ventilation. Fourteen rabbits were divided into group-1 (n = 8) with open-chest occlusion of left circumflex coronary artery and closed-chest reperfusion, and group-2 (n = 6) of non-ischemic control; and received ECG-triggered cMRI with delayed contrast enhancement (DE-cMRI) at a 1.5 T clinical scanner. The MI areas in group-1 were morphometrically compared between DE-cMRI and histochemically stained specimens. Left ventricular (LV) functions were compared between two groups.The success rate of intubation and reperfused MI was 8/8 and 6/8, respectively. Global and regional LV functions significantly decreased in group-1 as evidenced by significant hypokinesis of lateral LV-wall and wall thickening (P \ 0.001). Mean MI-area was 19.41 +/- 21.92% on DE-cMRI and 19.10 +/- 22.61% with histochemical staining (r = 0.985). Global MI-volume was 17.92 +/- 7.42% on DE-cMRI and 16.62 +/- 7.16% with histochemistry (r = 0.994). The usefulness of this model was successfully tested for assessing a new contrast agent. The present rabbit MI model may offer a practical platform for more translational research using clinical MRI-facilities.
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21
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Badea CT, Wetzel AW, Mistry N, Pomerantz S, Nave D, Johnson GA. Left ventricle volume measurements in cardiac micro-CT: the impact of radiation dose and contrast agent. Comput Med Imaging Graph 2008; 32:239-50. [PMID: 18243656 DOI: 10.1016/j.compmedimag.2007.12.004] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2006] [Revised: 10/03/2007] [Accepted: 12/17/2007] [Indexed: 10/24/2022]
Abstract
Micro-CT-based cardiac function estimation in small animals requires measurement of left ventricle (LV) volume at multiple time points during the cardiac cycle. Measurement accuracy depends on the image resolution, its signal and noise properties, and the analysis procedure. This work compares the accuracy of the Otsu thresholding and a region sampled binary mixture approach, for live mouse LV volume measurement using 100 microm resolution datasets. We evaluate both analysis methods after varying the volume of injected contrast agent and the number of projections used for CT reconstruction with a goal of permitting reduced levels of both X-ray and contrast agent doses.
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Affiliation(s)
- Cristian T Badea
- Center for In Vivo Microscopy, Duke University Medical Center, Box 3302, Durham, NC 27710, United States.
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22
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Abstract
Imaging is a noninvasive complement to traditional methods (such as histology) in rodent cardiac studies. Assessments of structure and function are possible with ultrasound, microcomputed tomography (microCT), and magnetic resonance (MR) imaging. Cardiac imaging in the rodent poses a challenge because of the size of the animal and its rapid heart rate. Each aspect in the process of rodent cardiac imaging-animal preparation, choice of anesthetic, selection of gating method, image acquisition, and image interpretation and measurement-requires careful consideration to optimize image quality and to ensure accurate and reproducible data collection. Factors in animal preparation that can affect cardiac imaging are the choice of anesthesia regime (injected or inhaled), intubated or free-breathing animals, physiological monitoring (ECG, respiration, and temperature), and animal restraint. Each will vary depending on the method of imaging and the length of the study. Gating strategies, prospective or retrospective, reduce physiological motion artifacts and isolate specific time points in the cardiac cycle (i.e., end-diastole and end-systole) where measurements are taken. This article includes a simple explanation of the physics of ultrasound, microCT, and MR to describe how images are generated. Subsequent sections provide reviews of animal preparation, image acquisition, and measurement techniques in each modality specific to assessing cardiac functions such as ejection fraction, fractional shortening, stroke volume, cardiac output, and left ventricular mass. The discussion also includes the advantages and disadvantages of the different imaging modalities. With the use of ultrasound, microCT, and MR, it is possible to create 2-, 3-, and 4-dimensional views to characterize the structure and function of the rodent heart.
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Affiliation(s)
- Kennita Johnson
- Laboratory of Experimental Pathology, National Institute of Environmental Health Sciences in Research Triangle Park, NC 27709, USA.
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23
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Ni M, Zhang M, Ding SF, Chen WQ, Zhang Y. Micro-ultrasound imaging assessment of carotid plaque characteristics in apolipoprotein-E knockout mice. Atherosclerosis 2008; 197:64-71. [PMID: 17870080 DOI: 10.1016/j.atherosclerosis.2007.07.039] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/13/2007] [Revised: 07/23/2007] [Accepted: 07/31/2007] [Indexed: 10/22/2022]
Abstract
This study was aimed to test the hypothesis that noninvasive assessment of carotid plaques can be achieved by high-resolution micro-ultrasound imaging in apolipoprotein-E knockout (apoE-KO) mice. Forty-two male apoE-KO mice were fed a high-fat diet and atherosclerotic lesions in the left common carotid artery were induced by perivascular placement of constrictive collars. Eight weeks after surgery, all mice were divided into interventional group (n=21) which received mental stress stimulation and intraperitoneal injection of lipopolysaccharide, and control group (n=21) which received only 0.9% sodium chloride solution for 4 weeks. Plaque morphology and flow velocities were evaluated by micro-ultrasonography. The results showed that micro-ultrasound imaging and corresponding cross-sectional histopathology data revealed positive correlations for plaque area, intima-medial thickness (IMT), eccentric index (EI) and remodeling index (RI) (all p<0.05). Ultrasound-derived IMT, EI and RI in the ruptured plaques were significantly greater than those in the nonruptured plaques (all p<0.05). Maximal flow velocity (Vmax) was higher in the ruptured plaque sites compared with nonruptured plaques sites (p<0.001). Multivariate logistic regression analysis revealed that IMT and Vmax were independent predictors of plaque rupture. In conclusion, micro-ultrasound imaging provides a reliable approach to the noninvasive and quantitative assessment of carotid plaques in apoE-KO mice.
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Affiliation(s)
- Mei Ni
- The Key Laboratory of Cardiovascular Remodeling and Function Research, Chinese Ministry of Education and Chinese Ministry of Health, Shandong University, Qilu Hospital, Jinan, Shandong, PR China
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Song Y, Du Y, Prabhu SD, Epstein PN. Diabetic Cardiomyopathy in OVE26 Mice Shows Mitochondrial ROS Production and Divergence Between In Vivo and In Vitro Contractility. Rev Diabet Stud 2007; 4:159-68. [PMID: 18084673 PMCID: PMC2174063 DOI: 10.1900/rds.2007.4.159] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Abstract
Many diabetic patients suffer from a cardiomyopathy that cannot be explained solely by poor coronary perfusion. This cardiomyopathy may be due to either organ-based damage like fibrosis, or to direct damage to cardiomyocytes. Mitochondrial-derived reactive oxygen species (ROS) have been proposed to contribute to this cardiomyopathy. To address these questions, we used the OVE26 mouse model of severe type 1 diabetes to measure contractility in isolated cardiomyocytes by edge detection and in vivo with echocardiography. We also assessed the source of ROS generation using both a general and a mitochondrial specific indicator. When contractility was assayed in freshly isolated myocytes, contraction was much stronger in control myocytes. However, contractility of normal myocytes became weaker during 24 hours of in vitro culture. In contrast, contractility of diabetic OVE26 myocytes remains stable during culture. Echocardiography revealed normal or hyperdynamic function in OVE26 hearts under basal conditions but with a sharply reduced response to isoproterenol, a beta-adrenergic agonist. For ROS generation, we found that ROS production in diabetic myocytes was elevated after exposure to either high glucose or angiotensin II (AngII). Superoxide detection with the mitochondrial sensor MitoSOX Red confirmed that mitochondria are a major source of ROS generation in diabetic myocytes. These results show that contractile deficits in OVE26 diabetic hearts are due primarily to cardiomyocyte impairment and that ROS from mitochondria are a cause of that impairment.
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Affiliation(s)
- Ye Song
- Department of Pediatrics, University of Louisville and Louisville VAMC, Louisville, Kentucky, USA
| | - Yibo Du
- Department of Pediatrics, University of Louisville and Louisville VAMC, Louisville, Kentucky, USA
| | - Sumanth D. Prabhu
- Department of Medicine/Cardiology, University of Louisville and Louisville VAMC, Louisville, Kentucky, USA
| | - Paul N. Epstein
- Department of Pediatrics, University of Louisville and Louisville VAMC, Louisville, Kentucky, USA
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Parzy E, Fromes Y, Thiaudiere E, Carlier PG. Refinement of cardiac NMR imaging in awake hamsters: proof of feasibility and characterization of cardiomyopathy. NMR IN BIOMEDICINE 2007; 20:615-23. [PMID: 17405188 DOI: 10.1002/nbm.1154] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/14/2023]
Abstract
The goal of this study was to demonstrate the feasibility of cardiac NMR imaging in conscious hamsters and its usefulness in evaluating cardiac abnormalities in a small-animal model of cardiomyopathy. Awake hamsters, controls and cardiomyopathic ones (CHF 147), were immobilized in a dedicated holder. Half-Fourier single-shot FSE imaging, with outer-volume suppression and 'black-blood' contrast provided images free from motion artifact with good visualization of cardiac anatomy at any point in the cardiac cycle. Series of double-oblique views were acquired with or without electrocardiograph gating. Image acquisition time was 55 ms, with an in-plane resolution of 470 x 625 microm2. Left ventricular volumes, ejection fraction, and myocardium NMR signal heterogeneity were compared in CHF 147 and control hearts. Left ventricles of CHF 147 hamsters were dilated, as indicated by the increase in end-diastolic cavity volume (299 +/- 79 mm3 compared with the controls (141 +/- 39 mm3; P = 0.0002). Left ventricular ejection fraction was largely reduced (45 +/- 9% vs 86 +/- 4%; P < 0.0001). The NMR signal distribution at an effective echo time of 41 ms was more heterogeneous in the myocardial wall of CHF 147 hamsters than in controls (1.87 +/- 0.37 a.u. vs 0.98 +/- 0.12 a.u., respectively; P = 0.0002). This study is a refinement of animal experimentation, as it demonstrates for the first time that characteristic features of cardiac pathology can be evaluated with ultra-fast NMR imaging in conscious small rodents.
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Affiliation(s)
- Elodie Parzy
- NMR Laboratory, AFM CEA, Institute of Myology, IFR14, Paris, France.
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Abstract
Transgenic and knockout mice can be used to study the genes and basic mechanisms involved in heart disease, and have therefore assumed a central role in modern cardiac research. MRI and MRS techniques have recently been developed for mice that enable the quantitative or semi-quantitative in vivo assessment of cardiac anatomy, function, perfusion, infarction, Ca(2+) influx, and metabolism. With these techniques, the normal mouse heart has been shown to be well suited as a model of human cardiac disease. The roles of individual genes in normal cardiac physiology have recently been studied by MR, including the role of neuronal nitric oxide synthase in beta-adrenergic stimulation, the roles of the inducible nitric oxide synthase and myoglobin in function, dilation, and energetics, and the role of cardiac troponin I in contractility. Furthermore, with a mouse model of myocardial infarction, the roles of the angiotensin II type 2 receptor, xanthine oxidase inhibitors, blood coagulation factor XIII, and inducible nitric oxide synthase in post-infarct function and remodeling have been further elucidated. Non-invasive in vivo MRI and MRS in mice provide a unique and powerful means for phenotyping genetically engineered mice and can improve our understanding of the roles of specific genes and proteins in cardiac physiology and pathophysiology.
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Affiliation(s)
- Frederick H Epstein
- Departments of Radiology and Biomedical Engineering, and the Cardiovascular Research Center, University of Virginia, Charlottesville, VA 22908, USA.
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27
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Thibault H, Gomez L, Donal E, Pontier G, Scherrer-Crosbie M, Ovize M, Derumeaux G. Acute myocardial infarction in mice: assessment of transmurality by strain rate imaging. Am J Physiol Heart Circ Physiol 2007; 293:H496-502. [PMID: 17384134 DOI: 10.1152/ajpheart.00087.2007] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
In vivo evaluation of the transmural extension of myocardial infarction (TEI) is crucial to prediction of viability and prognosis. With the rise of transgenic technology, murine myocardial infarction (MI) models are increasingly used. Our study aimed to evaluate systolic strain rate (SR), a new parameter of regional function, to quantify TEI in a murine model of acute MI induced by various durations of ischemia followed by 24 h of reperfusion. Global and regional left ventricular (LV) function were assessed by echocardiography (13 MHz, Vivid 7, GE) in 4 groups of wild-type mice (C57BL/6, 2 mo old): a sham-treated group (n = 10) and three MI groups [30 (n = 11), 60 (n = 10), and 90 (n = 9) min of left coronary artery occlusion]. Conventional LV dimensions, anterior wall (AW) thickening, and peak systolic SR were measured before and 24 h after reperfusion. Area at risk (AR) was measured by blue dye and infarct size (area of necrosis, AN) and TEI by triphenyltetrazolium chloride staining. AN increased with ischemia duration (25 +/- 2%, 56 +/- 5%, 71 +/- 6% of AR for 30, 60, and 90 min, respectively; P < 0.05). LV end-diastolic volume significantly increased with ischemia duration (30 +/- 5, 34 +/- 5, 43 +/- 5 microl; P < 0.05), whereas LV ejection fraction decreased (63 +/- 5%, 58 +/- 6%, 46 +/- 5%; P < 0.05). AW thickening decrease was not influenced by ischemia duration. Conversely, systolic SR decreased with ischemia duration (13 +/- 5, 4 +/- 3, -2 +/- 6 s(-1); P < 0.05) and was significantly correlated with TEI (r = 0.89, P < 0.01). Receiver operating characteristic (ROC) curves identified systolic SR as the most accurate parameter to predict TEI. In conclusion, in a murine model of MI, SR imaging is superior to conventional echocardiography to predict TEI early after MI.
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Affiliation(s)
- Hélène Thibault
- Faculté de Médecine Lyon Nord, INSERM E 0226, 8 Avenue Rockefeller, 69373 Lyon cedex 8, France
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Croisille P, Rotaru C, Janier M, Hiba B. Gender and strain variations in left ventricular cardiac function and mass determined with magnetic resonance imaging at 7 tesla in adult mice. Invest Radiol 2007; 42:1-7. [PMID: 17213743 DOI: 10.1097/01.rli.0000248892.35531.ea] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVES We sought to assess with magnetic resonance imaging (MRI) the influence of strain type and gender on left ventricular (LV) global function and mass in 3 inbred mouse strains with a normal cardiac phenotype. MATERIALS AND METHODS A total of 30 mice from 3 inbred strains (C57BL/6, 29S2/SvPasCrl, and C3HFeJ) were studied on a 7.05-T MR scanner using ECG-triggered cine sequences. LV mass and volumes were calculated with inclusion and exclusion of papillary muscles (PMs) in the LV wall. RESULTS Significant differences were found with strain and gender (P < 0.001), with strain-effect but no gender-effect for ejection fraction (EF), end-diastolic volume (EDV), and end-systolic volume (ESV). There were no differences in LV mass between strains but lower values in female mice except in the C3H strain. The exclusion of PMs led to the relative underestimation of EF (-6.1%) and of LV mass (-6.4 mg) and the relative overestimation of EDV (6.3 microL) and ESV (5.3 microL). Inter- and intraobserver reproducibility was better when PMs were included. CONCLUSION The use of MRI demonstrates cardiac interstrain and gender-related phenotypic diversities that are essential factors to consider when building genomic databases and designing studies.
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Yu X, Tesiram YA, Towner RA, Abbott A, Patterson E, Huang S, Garrett MW, Chandrasekaran S, Matsuzaki S, Szweda LI, Gordon BE, Kem DC. Early myocardial dysfunction in streptozotocin-induced diabetic mice: a study using in vivo magnetic resonance imaging (MRI). Cardiovasc Diabetol 2007; 6:6. [PMID: 17309798 PMCID: PMC1805425 DOI: 10.1186/1475-2840-6-6] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/05/2007] [Accepted: 02/19/2007] [Indexed: 12/25/2022] Open
Abstract
Background Diabetes is associated with a cardiomyopathy that is independent of coronary artery disease or hypertension. In the present study we used in vivo magnetic resonance imaging (MRI) and echocardiographic techniques to examine and characterize early changes in myocardial function in a mouse model of type 1 diabetes. Methods Diabetes was induced in 8-week old C57BL/6 mice with two intraperitoneal injections of streptozotocin. The blood glucose levels were maintained at 19–25 mmol/l using intermittent low dosages of long acting insulin glargine. MRI and echocardiography were performed at 4 weeks of diabetes (age of 12 weeks) in diabetic mice and age-matched controls. Results After 4 weeks of hyperglycemia one marker of mitochondrial function, NADH oxidase activity, was decreased to 50% of control animals. MRI studies of diabetic mice at 4 weeks demonstrated significant deficits in myocardial morphology and functionality including: a decreased left ventricular (LV) wall thickness, an increased LV end-systolic diameter and volume, a diminished LV ejection fraction and cardiac output, a decreased LV circumferential shortening, and decreased LV peak ejection and filling rates. M-mode echocardiographic and Doppler flow studies of diabetic mice at 4 weeks showed a decreased wall thickening and increased E/A ratio, supporting both systolic and diastolic dysfunction. Conclusion Our study demonstrates that MRI interrogation can identify the onset of diabetic cardiomyopathy in mice with its impaired functional capacity and altered morphology. The MRI technique will lend itself to repetitive study of early changes in cardiac function in small animal models of diabetic cardiomyopathy.
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Affiliation(s)
- Xichun Yu
- Department of Medicine, University of Oklahoma Health Sciences Center & VAMC, Oklahoma City, OK 73104, USA
- Cardiac Arrhythmia Research Institute, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA
| | - Yasvir A Tesiram
- Small Animal MRI Core Facility, Oklahoma Medical Research Foundation, Oklahoma City, OK 73104, USA
| | - Rheal A Towner
- Small Animal MRI Core Facility, Oklahoma Medical Research Foundation, Oklahoma City, OK 73104, USA
| | - Andrew Abbott
- Small Animal MRI Core Facility, Oklahoma Medical Research Foundation, Oklahoma City, OK 73104, USA
| | - Eugene Patterson
- Cardiac Arrhythmia Research Institute, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA
| | - Shijun Huang
- Department of Medicine, University of Oklahoma Health Sciences Center & VAMC, Oklahoma City, OK 73104, USA
- Cardiac Arrhythmia Research Institute, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA
| | - Marion W Garrett
- Department of Medicine, University of Oklahoma Health Sciences Center & VAMC, Oklahoma City, OK 73104, USA
| | - Suresh Chandrasekaran
- Cardiac Arrhythmia Research Institute, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA
| | - Satoshi Matsuzaki
- Free Radical Biology and Aging Research Program, Oklahoma Medical Research Foundation, Oklahoma City, OK 73104, USA
| | - Luke I Szweda
- Free Radical Biology and Aging Research Program, Oklahoma Medical Research Foundation, Oklahoma City, OK 73104, USA
| | - Brian E Gordon
- Laboratory Animal Resource Center, Oklahoma Medical Research Foundation, Oklahoma City, OK 73104, USA
| | - David C Kem
- Department of Medicine, University of Oklahoma Health Sciences Center & VAMC, Oklahoma City, OK 73104, USA
- Cardiac Arrhythmia Research Institute, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA
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Abstract
Echocardiographic techniques are commonly utilized to describe the rodent cardiovascular phenotype. These approaches are contrasted with other in vivo methods and are positioned in the assay selection process by a review of studies from our laboratory and others. Although not conventionally considered a biomarker, the technique has the potential to be exploited as a marker of intentional or unanticipated toxic biological effects in the preclinical development of drugs and chemicals.
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Affiliation(s)
- Brian D Hoit
- Department of Medicine, University Hospitals of Cleveland and Case Western Reserve University, Cleveland, Ohio 44106, USA.
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31
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Badea CT, Bucholz E, Hedlund LW, Rockman HA, Johnson GA. Imaging methods for morphological and functional phenotyping of the rodent heart. Toxicol Pathol 2006; 34:111-7. [PMID: 16507552 DOI: 10.1080/01926230500404126] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
Small animal imaging has a critical role in phenotyping, drug discovery, and in providing a basic understanding of mechanisms of disease. Translating imaging methods from humans to small animals is not an easy task. The purpose of this work is to compare two cardiac imaging modalities, i.e., magnetic resonance microscopy (MRM) and microcomputed tomography (CT) for preclinical studies on rodents. We present the two technologies, the parameters that they can measure, the types of alterations that they can detect, and show how these imaging methods compare to techniques available in clinical medicine. While this paper does not refer per se to the cardiac risk assessment for drug or chemical development, we hope that the information will effectively address how MRM and micro-CT might be exploited to measure biomarkers critical for safety assessment.
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Affiliation(s)
- Cristian T Badea
- Center for In Vivo Microscopy, Duke University Medical Center, Durham, North Carolina 27710, USA.
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Sharp TL, Dence CS, Engelbach JA, Herrero P, Gropler RJ, Welch MJ. Techniques necessary for multiple tracer quantitative small-animal imaging studies. Nucl Med Biol 2006; 32:875-84. [PMID: 16253813 DOI: 10.1016/j.nucmedbio.2005.05.010] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2005] [Revised: 05/31/2005] [Accepted: 05/31/2005] [Indexed: 11/27/2022]
Abstract
INTRODUCTION An increasing number and variety of studies on rodent models are being conducted using small-animal positron emission tomography scanners. We aimed to determine if animal handling techniques could be developed to perform routine animal imaging in a timely and efficient manner and with minimal effect on animal physiology. These techniques need to be reproducible in the same animal while maintaining hemodynamic and physiological stability. METHODS The necessary techniques include (a) the use of inhalant anesthesia, (b) arterial and venous cannulation for multiple tracer administrations and blood sampling, (c) development of small-volume analytic columns and techniques and (d) measurement of the physiological environment during the imaging session. RESULTS We provide an example of a cardiac imaging study using four radiotracers (15O-water, 1-[11C]-acetate, 1-[11C]-palmitate and 1-[11C]-glucose) injected into normal rats. Plasma substrates, CO2 production and total metabolites were measured. The animals remained anesthetized over the entire imaging session, and their physiological state was maintained. CONCLUSION The intrastudy stability of the physiological measurements and substrate levels and interstudy reproducibility of the measurements are reported.
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Affiliation(s)
- Terry L Sharp
- Division of Radiological Sciences, The Mallinckrodt Institute of Radiology, Washington University School of Medicine, Campus Box 8225, St. Louis, MO 63110, USA
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Xue L, Locke GR, Camilleri M, Schuurkes JAJ, Meulemans A, Coulie BJ, Szurszewski JH, Farrugia G. Effect of modulation of serotonergic, cholinergic, and nitrergic pathways on murine fundic size and compliance measured by ultrasonomicrometry. Am J Physiol Gastrointest Liver Physiol 2006; 290:G74-82. [PMID: 16166345 PMCID: PMC1434468 DOI: 10.1152/ajpgi.00244.2005] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Reduced fasting or postprandial gastric volumes have been implicated in the pathophysiology of functional dyspepsia. The mechanisms that underlie the control of gastric fundic volume are incompletely understood, partly because of an inability to accurately measure fundic volume in vivo in small animals. Small animals are useful models to evaluate mechanisms, e.g., in knockout animals. The aim of this study was to determine whether an ultrasonometric technique accurately monitors fundic contraction and relaxation in mice in vivo and to determine the effect of modulation of cholinergic, nitrergic, and serotonergic pathways on fundic size and compliance in the intact mouse innervated stomach. Two to four piezoelectric crystals (diameter 1 mm, 24-microm resolution) were glued to the serosal side of fundus and used to measure distance. Validation studies showed excellent correlation between measured changes and actual changes in distances between crystals and excellent reproducibility. The expected responses to pharmacological modulation with bethanechol and nitroglycerin were demonstrated. Atropine increased the distance between the crystals, suggesting a baseline cholinergic regulation of fundic volume. Bethanechol, Nomega-nitro-L-arginine, and the 5-HT1B/D agonist sumatriptan decreased the distance between the crystals, suggesting fundic contraction. Atropine, nitroglycerin, and buspirone caused an increase in intercrystal distance consistent with fundic relaxation. Fundic compliance was investigated by changing intragastric pressure via an implanted catheter. Sumatriptan increased compliance, whereas buspirone increased the distance between crystals but did not change compliance. The data suggest that ultrasonomicrometry is a useful tool that can reproducibly and accurately measure changes in fundic size and the response to pharmacological agents.
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Affiliation(s)
- Lin Xue
- Enteric NeuroScience Program, Mayo Clinic College of Medicine, Rochester, MN 55905, USA
| | - G. Richard Locke
- Enteric NeuroScience Program, Mayo Clinic College of Medicine, Rochester, MN 55905, USA
| | - Michael Camilleri
- Enteric NeuroScience Program, Mayo Clinic College of Medicine, Rochester, MN 55905, USA
| | | | - Ann Meulemans
- Johnson & Johnson Pharmaceutical Research and Development, Beerse, Belgium
| | - Bernard J. Coulie
- Johnson & Johnson Pharmaceutical Research and Development, Beerse, Belgium
| | - Joseph H. Szurszewski
- Enteric NeuroScience Program, Mayo Clinic College of Medicine, Rochester, MN 55905, USA
| | - Gianrico Farrugia
- Enteric NeuroScience Program, Mayo Clinic College of Medicine, Rochester, MN 55905, USA
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Schaefer A, Meyer GP, Brand B, Hilfiker-Kleiner D, Drexler H, Klein G. Effects of anesthesia on diastolic function in mice assessed by echocardiography. Echocardiography 2005; 22:665-70. [PMID: 16174120 DOI: 10.1111/j.1540-8175.2005.40096.x] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
BACKGROUND Transthoracic echocardiography is the predominant diagnostic tool to evaluate systolic and diastolic cardiac function noninvasively in mice. It is known that systolic function is substantially influenced by anesthetic agents used for sedation during echocardiography. However, the effect on diastolic function has not been investigated yet. The following study was conducted to evaluate the influence of different agents on diastolic left ventricular function in mice. METHODS AND RESULTS The effect of ketamine/xylazine (K/X), ketamine/midazolam (K/M), and tribromoethanol (TBE, Avertin) on diastolic function was measured 5, 15, and 25 minutes after the onset of anesthesia. Ratio of peak early-to-late myocardial diastolic velocities (Ea/Aa; determined by tissue Doppler imaging; TDI), ratio of peak transmitral early (E)- and late-diastolic velocity (E/A), deceleration time (DT), and isovolumic relaxation time (IVRT) correlated significantly with heart rate (HR). Overall, increasing HR contributed to a decrease of E/A-, Ea/Aa ratio, IVRT, and DT, whereas agents characterized by the strongest variation of HR (K/M and TBE) were associated with the greatest effect on diastolic function. CONCLUSION Left ventricular diastolic function in mice, determined by echocardiography, is dependent on anesthetic agent and timing of measurements after onset of anesthesia.
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Affiliation(s)
- Arnd Schaefer
- Department of Cardiology and Angiology, Hannover Medical School, Hannover, Germany.
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35
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Thibault H, Lafitte S, Timperley J, Tariosse L, Becher H, Roudaut R, Dos Santos P. Quantitative Analysis of Myocardial Perfusion in Rats by Contrast Echocardiography. J Am Soc Echocardiogr 2005; 18:1321-8. [PMID: 16376761 DOI: 10.1016/j.echo.2005.09.007] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/14/2005] [Indexed: 11/25/2022]
Abstract
BACKGROUND The ability to assess myocardial perfusion in small animals is important, especially to investigate models of myocardial ischemia. Myocardial perfusion is usually assessed by postmortem techniques, eliminating the possibility of follow-up. We sought to evaluate whether contrast echocardiography was able to quantify myocardial perfusion in rats. METHODS Twenty-four rats divided in 3 groups (sham-operated, and 8 and 21 days after left anterior descending coronary artery stenosis) underwent myocardial contrast echocardiography using intermittent triggered imaging. Peak plateau intensity and slope of refilling were compared with myocardial blood flow achieved with fluorescent microspheres. RESULTS High-quality images were easily obtained for each experiment. Close correlation was found between myocardial contrast echocardiography and myocardial blood flow, especially for measurements of peak plateau intensity x slope of refilling relative to the control area (y = 1.15 x -0.14, r = 0.86). CONCLUSION Quantification of myocardial perfusion in rats is feasible by myocardial contrast echocardiography using intermittent triggered imaging.
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36
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Borisov AB, Sutter SB, Kontrogianni-Konstantopoulos A, Bloch RJ, Westfall MV, Russell MW. Essential role of obscurin in cardiac myofibrillogenesis and hypertrophic response: evidence from small interfering RNA-mediated gene silencing. Histochem Cell Biol 2005; 125:227-38. [PMID: 16205939 DOI: 10.1007/s00418-005-0069-x] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/02/2005] [Indexed: 12/31/2022]
Abstract
Obscurin is a recently identified giant multidomain muscle protein (approximately 800 kDa) whose structural and regulatory functions remain to be defined. The goal of this study was to examine the effect of obscurin gene silencing induced by RNA interference on the dynamics of myofibrillogenesis and hypertrophic response to phenylephrine in cultured rat cardiomyocytes. We found that that the adenoviral transfection of short interfering RNA (siRNA) constructs targeting the first coding exon of obscurin sequence resulted in progressive depletion of cellular obscurin. Confocal microscopy demonstrated that downregulation of obscurin expression led to the impaired assembly of new myofibrillar clusters and considerable aberrations of the normal structure of the contractile apparatus. While the establishment of the initial periodic pattern of alpha-actinin localization remained mainly unaffected in siRNA-transfected cells, obscurin depletion did cause the defective lateral alignment of myofibrillar bundles, leading to their abnormal bifurcation, dispersal and multiple branching. Bending of immature myofibrils, apparently associated with the loss of their rigidity, a modified titin pattern, the absence of well-formed A-bands in newly formed contractile structures as documented by a diffuse localization of sarcomeric myosin labeling, and an occasional irregular periodicity of sarcomere spacing were typical of obscurin siRNA-treated cells. These results suggest that obscurin is indispensable for spatial positioning of contractile proteins and for the structural integration and stabilization of myofibrils, especially at the stage of myosin filament incorporation and A-band assembly. This demonstrates a vital role for obscurin in myofibrillogenesis and hypertrophic growth.
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Affiliation(s)
- Andrei B Borisov
- Division of Pediatric Cardiology, Department of Pediatrics and Communicable Diseases, University of Michigan Medical School, Ann Arbor, MI 48109, USA.
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37
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Jones GLAH, Sang E, Goddard C, Mortishire-Smith RJ, Sweatman BC, Haselden JN, Davies K, Grace AA, Clarke K, Griffin JL. A Functional Analysis of Mouse Models of Cardiac Disease through Metabolic Profiling. J Biol Chem 2005; 280:7530-9. [PMID: 15546876 DOI: 10.1074/jbc.m410200200] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Since the completion of the human and mouse genomes, the focus in mammalian biology has been on assessing gene function. Tools are needed for assessing the phenotypes of the many mouse models that are now being generated, where genes have been "knocked out," "knocked in," or mutated, so that gene expression can be understood in its biological context. Metabolic profiling of cardiac tissue through high resolution NMR spectroscopy in conjunction with multivariate statistics has been used to classify mouse models of cardiac disease. The data sets included metabolic profiles from mouse models of Duchenne muscular dystrophy, two models of cardiac arrhythmia, and one of cardiac hypertrophy. The metabolic profiles demonstrate that the strain background is an important component of the global metabolic phenotype of a mouse, providing insight into how a given gene deletion may result in very different responses in diverse populations. Despite these differences associated with strain, multivariate statistics were capable of separating each mouse model from its control strain, demonstrating that metabolic profiles could be generated for each disease. Thus, this approach is a rapid method of phenotyping mouse models of disease.
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Affiliation(s)
- Gareth L A H Jones
- Department of Biochemistry, University of Cambridge, Cambridge CB2 1GA, United Kingdom
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38
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Kawahara Y, Tanonaka K, Daicho T, Nawa M, Oikawa R, Nasa Y, Takeo S. Preferable Anesthetic Conditions for Echocardiographic Determination of Murine Cardiac Function. J Pharmacol Sci 2005; 99:95-104. [PMID: 16177543 DOI: 10.1254/jphs.fp0050343] [Citation(s) in RCA: 71] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022] Open
Abstract
Ketamine and xylazine are routinely used for measurement of hemodynamics of mice and rats by echocardiography. The anesthetic agents produce low heart rate (HR) in the animals, which may result in misleading data in the hemodynamic profiles of the small animals. The purpose of the present study was to select an appropriate anesthetic condition in the evaluation of mouse and rat cardiac function by echocardiography. Echocardiographic measurement was performed in male C57BL6 mice anesthetized with an intraperitoneal injection of 30 or 40 mg/kg pentobarbital (P30 or P40) or a combination of 60 mg/kg ketamine and 6 mg/kg xylazine (KX) and in male Wistar rats with an intraperitoneal injection of 40 or 50 mg/kg pentobarbital (P40 or P50) or a combination of 100 mg/kg ketamine and 10 mg/kg xylazine (KX). Basal HR of P30-anesthetized mice and P40-anesthetized were comparable to those in the conscious state, whereas KX-anesthetized mice and rats were 38% and 74% of those of the conscious animals, respectively. Fractional shortening (FS) and cardiac output index (COI) of the P30-anesthetized mice or the P40-anesthetized rats were greater than those of KX-anesthetized animals. Intraperitoneal injection of dobutamine at 0.3 and 1 mg/kg increased HR, FS, and COI of the P30-anesthetized mice and the P40-anesthetized rats, respectively, whereas the percent responses of these parameters in KX animals were greater than those in pentobarbital-anesthetized ones due to the lower basal values for the cardiac functional parameters. Anesthesia with P30 for the mouse and P40 for the rat rather than ketamine/xylazine may be relevant to the evaluation of cardiac function using echocardiography.
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Affiliation(s)
- Yuji Kawahara
- Department of Molecular and Cellular Pharmacology, Tokyo University of Pharmacy and Life Science, Hachioji, Japan
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39
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Vallée JP, Ivancevic MK, Nguyen D, Morel DR, Jaconi M. Current status of cardiac MRI in small animals. MAGNETIC RESONANCE MATERIALS IN PHYSICS BIOLOGY AND MEDICINE 2004; 17:149-56. [PMID: 15605278 DOI: 10.1007/s10334-004-0066-4] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/02/2004] [Revised: 08/27/2004] [Accepted: 09/15/2004] [Indexed: 10/26/2022]
Abstract
Cardiac magnetic resonance imaging (MRI) on small animals is possible but remains challenging and not well standardized. This publication aims to provide an overview of the current techniques, applications and challenges of cardiac MRI in small animals for researchers interested in moving into this field. Solutions have been developed to obtain a reliable cardiac trigger in both the rat and the mouse. Techniques to measure ventricular function and mass have been well validated and are used by several research groups. More advanced techniques like perfusion imaging, delayed enhancement or tag imaging are emerging. Regarding cardiac applications, not only coronary ischemic disease but several other pathologies or conditions including cardiopathies in transgenic animals have already benefited from these new developments. Therefore, cardiac MRI has a bright future for research in small animals.
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Affiliation(s)
- J-P Vallée
- Digital Imaging Unit, Radiology and Medical Informatics Department, Geneva University Hospitals, CH-1211, Geneva 14, Switzerland.
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40
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Severson DL. Diabetic cardiomyopathy: recent evidence from mouse models of type 1 and type 2 diabetes. Can J Physiol Pharmacol 2004; 82:813-23. [PMID: 15573141 DOI: 10.1139/y04-065] [Citation(s) in RCA: 88] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Diabetic cardiomyopathy is defined as ventricular dysfunction of the diabetic heart in the absence of coronary artery disease. With the use of both in vivo and ex vivo techniques to assess cardiac phenotype, reduced contractile performance can be observed in experiments with mouse models of both type 1 (insulin-deficient) and type 2 (insulin-resistant) diabetes. Both systolic dysfunction (reduced left ventricular pressures and decreased cardiac output) and diastolic dysfunction (impaired relaxation) is observed in diabetic hearts, along with enhanced susceptibility to ischemic injury. Metabolism is also altered in diabetic mouse hearts: glucose utilization is reduced and fatty acid utilization is increased. The use of geneticallyengineered mice has provided a powerful experimental approach to test mechanisms that may be responsible for the deleterious effects of diabetes on cardiac function.Key words: cardiac function, cardiac metabolism, cardiac phenotype.
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Affiliation(s)
- David L Severson
- Department of Pharmacology and Therapeutics, Faculty of Medicine, University of Calgary, AB, Canada.
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41
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Zhou YQ, Foster FS, Nieman BJ, Davidson L, Chen XJ, Henkelman RM. Comprehensive transthoracic cardiac imaging in mice using ultrasound biomicroscopy with anatomical confirmation by magnetic resonance imaging. Physiol Genomics 2004; 18:232-44. [PMID: 15114000 DOI: 10.1152/physiolgenomics.00026.2004] [Citation(s) in RCA: 98] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
High-frequency ultrasound biomicroscopy (UBM) has recently emerged as a high-resolution means of phenotyping genetically altered mice and has great potential to evaluate the cardiac morphology and hemodynamics of mouse mutants. However, there is no standard procedure of in vivo transthoracic cardiac imaging using UBM to comprehensively phenotype the adult mice. In this paper, the characteristic mouse thoracic anatomy is elucidated using magnetic resonance (MR) imaging on fixed mice. Besides the left parasternal and apical windows commonly used for transthoracic ultrasound cardiac imaging, a very useful right parasternal window is found. We present strategies for optimal visualization using UBM of key cardiac structures including: 1) the right atrial inflow channels such as the right superior vena cava; 2) the right ventricular inflow tract via the tricuspid orifice; 3) the right ventricular outflow tract to the main pulmonary artery; 4) the left atrial inflow channel, e.g., pulmonary vein; 5) the left ventricular inflow tract via the mitral orifice; 6) the left ventricular outflow tract to the ascending aorta; 7) the left coronary artery; and 8) the aortic arch and associated branches. Two-dimensional ultrasound images of these cardiac regions are correlated to similar sections in the three-dimensional MR data set to verify anatomical details of the in vivo UBM imaging. Dimensions of the left ventricle and ascending aorta are measured by M-mode. Flow velocities are recorded using Doppler at six representative intracardiac locations: right superior vena cava, tricuspid orifice, main pulmonary artery, pulmonary vein, mitral orifice, and ascending aorta. The methodologies and baseline measurements of inbred mice provide a useful guide for investigators applying the high-frequency ultrasound imaging to mouse cardiac phenotyping.
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Affiliation(s)
- Yu-Qing Zhou
- Mouse Imaging Centre at Hospital for Sick Children, Toronto, Ontario, Canada M5G 1X8.
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42
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Goode TL, Klein HJ. Miniaturization: an overview of biotechnologies for monitoring the physiology and pathophysiology of rodent animal models. ILAR J 2003; 43:136-46. [PMID: 12105381 DOI: 10.1093/ilar.43.3.136] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Recent advances in bioengineering technologies have made it possible to collect high-quality reproducible data quantitatively in a wide range of laboratory animal species, including rodents. Several of these technologies are incorporated into a plan called Miniaturization, which aims to design, develop, and maintain rodent animal models to study the pathophysiology and therapy of human diseases. Laser Doppler flowmetry, digital sonomicrometry, bioelectrical impedance, and microdialysis are some of the most widely used methods under the plan because they cause minimal pain and distress, reduce the number of animals used in biomedical research, and allow chronic, nonterminal assessment of physiological parameters in rodents. An overview of each of these technologies and their major applications in rodents used for biomedical research is provided.
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Affiliation(s)
- Tamara L Goode
- Department of Laboratory Animal Resources, Merck Research Laboratories, West Point, PA, USA
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43
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Abstract
Mice have become the mammalian model of choice for the application of genetics in biomedical research due to the evolutionary conservation of physiological systems and their attendant pathologies among all mammals as well as the exceptional power of genetic research technologies in the species. Beginning from aberrant phenotypes, a large number of mouse mutants and natural polymorphisms have been cloned, providing much information about the molecular basis of physiological processes. Additionally, the variable expression of these mutations in different inbred strain backgrounds has demonstrated the importance of modifier genes, which are also susceptible to cloning. Research efforts are keeping pace with these developments. In the area of gene discovery, large, government-funded mutagenesis programs now exist, and as a matter of great practical importance, recent evidence suggests that the same genes may be involved in the natural polymorphisms affecting disease in mice and humans. In parallel, dramatic advances are also being made in our ability to measure physiological processes in mice, and the advent of expression profiling promises revolutionary advances in understanding phenotype at the molecular level. Gene-driven approaches have relied on engineering the mouse genome, including adding, subtracting, and replacing genes and, most recently, the ability to control gene activity reversibly. Together, these multiple advances in our technical abilities have created extraordinary opportunities for future discovery.
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44
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Wu MC, Gao DW, Sievers RE, Lee RJ, Hasegawa BH, Dae MW. Pinhole single-photon emission computed tomography for myocardial perfusion imaging of mice. J Am Coll Cardiol 2003; 42:576-82. [PMID: 12906991 DOI: 10.1016/s0735-1097(03)00716-2] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
OBJECTIVES Although transgenic mice have emerged as powerful experimental models of cardiovascular disease, methods for in vivo phenotypic assessment and characterization remain limited, motivating the development of new instruments for biologic measurement. BACKGROUND We have developed a single-photon emission computed tomography system with a pinhole collimator (pinhole SPECT) for high-resolution cardiovascular imaging of mice. In this study, we describe a protocol for myocardial perfusion imaging of mice using technetium-99m ((99m)Tc)-sestamibi and demonstrate the feasibility for measurement of perfusion defect size from pinhole SPECT images. METHODS Mice were anesthetized and injected with 370 MBq (10 mCi) of (99m)Tc-sestamibi. Tomographic projection images were acquired by rotating each mouse in a vertical axis in front of a stationary clinical scintillation camera equipped with a pinhole collimator. BALB/c mice (n = 15) were imaged after the permanent ligation of the left anterior descending coronary artery. The resulting defect size was measured from circumferential profiles of short-axis images. After imaging, the hearts were excised and sectioned to obtain ultra-high resolution digital autoradiographs of (99m)Tc-sestamibi, from which the actual infarct size was determined. RESULTS Reconstructed image quality was equivalent to that obtained for clinical myocardial perfusion imaging. Linear regression analysis produced a correlation coefficient of 0.83 (p < 0.001) between the measured and actual values of the defect size. CONCLUSIONS These results demonstrate that myocardial perfusion can be characterized qualitatively and quantitatively in mice using pinhole SPECT.
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Affiliation(s)
- Max C Wu
- Department of Radiology, University of California, San Francisco, California, USA
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45
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Broberg CS, Pantely GA, Barber BJ, Mack GK, Lee K, Thigpen T, Davis LE, Sahn D, Hohimer AR. Validation of the myocardial performance index by echocardiography in mice: a noninvasive measure of left ventricular function. J Am Soc Echocardiogr 2003; 16:814-23. [PMID: 12878990 DOI: 10.1067/s0894-7317(03)00399-7] [Citation(s) in RCA: 75] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
BACKGROUND The myocardial performance index (MPI) is a Doppler-based measure of left ventricular (LV) function. It is noninvasive, independent of LV shape, and does not require dimensional measurements. However, it has never been validated in mice. METHODS A total of 29 anesthetized mice with LV pressure catheters underwent echocardiography (2-dimensional, M-mode, and Doppler) at baseline and during manipulations of beta-adrenergic tone, temperature, preload, and afterload. The maximum derivative of LV pressure with respect to time (dP/dt(max)) was compared with MPI, fractional shortening (FS), mean velocity of circumferential fiber shortening, and the FS/MPI ratio. RESULTS MPI (baseline 0.44 +/- 0.07) correlated strongly with dP/dt(max) (R = -.779, P <.001), as did FS and mean velocity of circumferential fiber shortening. MPI differed significantly with contractility, preload, and afterload manipulation. FS/MPI showed the best correlation with dP/dt(max). CONCLUSIONS MPI strongly correlates with dP/dt(max) over a range of hemodynamic conditions in mice. It can be used as a noninvasive index of LV function in this species.
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Affiliation(s)
- Craig S Broberg
- Divisions of Cardiology, Oregon Health and Science University, Portland, Oregon 97221, USA
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46
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Fitzgerald SM, Gan L, Wickman A, Bergström G. Cardiovascular and renal phenotyping of genetically modified mice: a challenge for traditional physiology. Clin Exp Pharmacol Physiol 2003; 30:207-16. [PMID: 12680837 DOI: 10.1046/j.1440-1681.2003.03818.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
1. The advent of techniques to genetically modify experimental animals and produce directed mutations in both a conditional and tissue-specific manner has dramatically opened up new fields for physiologists in cardiovascular and renal research. 2. A consequence of altering the genetic background of mice is the difficulty in predicting the phenotypic outcome of the genetic mutation. We therefore suggest that physiologists may need to change their current experimental paradigms to face this new era. Hence, our aim is to propose a complementary research philosophy for physiologists working in the post-genomic era. That is, instead of using strictly hypothesis-driven research philosophies, one will have to perform screening studies of mutant mice, within a field of interest, to find valuable phenotypes. Once a relevant phenotype is found, in-depth studies of the underlying mechanisms should be performed. These follow-up studies should be performed using a traditional hypothesis-driven research philosophy. 3. The rapidly increasing availability of mutated mouse models of human disease also necessitates the development of techniques to characterize these various mouse phenotypes. In particular, the miniaturization and refinement of techniques currently used to study the renal and cardiovascular system in larger animals will be discussed in the present review. Hence, we aim to outline what techniques are currently available and should be present in a laboratory to screen and study renal and cardiovascular phenotypes in genetically modified mice, with particular emphasis on methodologies used in the intact, conscious animal.
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Affiliation(s)
- Sharyn M Fitzgerald
- Department of Physiology, Institute of Physiology and Pharmacology, Göteborg University, Sweden
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47
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Massoud TF, Gambhir SS. Molecular imaging in living subjects: seeing fundamental biological processes in a new light. Genes Dev 2003; 17:545-80. [PMID: 12629038 DOI: 10.1101/gad.1047403] [Citation(s) in RCA: 1417] [Impact Index Per Article: 67.5] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Affiliation(s)
- Tarik F Massoud
- The Crump Institute for Molecular Imaging, David Geffen School of Medicine at University of California at Los Angeles, Los Angeles, California 90095, USA
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48
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Tiemann K, Weyer D, Djoufack PC, Ghanem A, Lewalter T, Dreiner U, Meyer R, Grohe C, Fink KB. Increasing myocardial contraction and blood pressure in C57BL/6 mice during early postnatal development. Am J Physiol Heart Circ Physiol 2003; 284:H464-74. [PMID: 12414444 DOI: 10.1152/ajpheart.00540.2002] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Knowledge of the developmental changes of cardiovascular parameters in the genetic background of a mouse strain is important for understanding phenotypic changes in transgenic or knockout mouse models for heart disease. We studied arterial blood pressure and myocardial contractility in mice of the common background strain C57BL/6, aged 21 days [postnatal day 21 (P21)] to 580 days. Heart rate increased during maturation from 396 beats/min at P21 to 551 beats/min at postnatal day 50 (P50), and mean arterial blood pressure increased in parallel from 86 to 110 mmHg and remained constant afterward. Echocardiographically determined left ventricular myocardial wall dimensions (R = 0.79, P < 0.0001) and left ventricular mass calculated using the area-length algorithm correlated strongly with histomorphometrical measurements (R = 0.93, P < 0.001). Sarcomere shortening records from isolated ventricular myocytes used as a measure for myocardial contractility revealed a negative shortening-frequency relation under a pacing frequency of 2 Hz and a positive relation above 2 Hz. Shortening amplitudes recorded from P21 myocytes were smaller, and the shortening-frequency relation was less steep than in adult myocytes. A stimulation pause was followed by a negative "staircase" at pacing frequency of < or =6 Hz and a positive staircase at > or =6 Hz. P21 myocytes developed positive staircases at 8 and 10 Hz, and adult myocytes also developed them at 6 Hz. Blood pressure increase during maturation until P50 may originate from increasing single cardiomyocyte contractility.
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Affiliation(s)
- Klaus Tiemann
- Department of Pharmacology, Universitätsklinik Bonn, Germany
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Creemers EEJM, Davis JN, Parkhurst AM, Leenders P, Dowdy KB, Hapke E, Hauet AM, Escobar PG, Cleutjens JPM, Smits JFM, Daemen MJAP, Zile MR, Spinale FG. Deficiency of TIMP-1 exacerbates LV remodeling after myocardial infarction in mice. Am J Physiol Heart Circ Physiol 2003; 284:H364-71. [PMID: 12388239 DOI: 10.1152/ajpheart.00511.2002] [Citation(s) in RCA: 141] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Recent studies have been directed at modulating the heart failure process through inhibition of activated matrix metalloproteinases (MMPs). We hypothesized that a loss of MMP inhibitory control by tissue inhibitor of MMP (TIMP)-1 deficiency alters the course of postinfarction chamber remodeling and induced chronic myocardial infarction (MI) in wild-type (WT) and TIMP-1(-/-) mice. Left ventricular (LV) pressure-volume loops obtained from WT and TIMP-1(-/-) mice demonstrated that LV end-diastolic volume [52 +/- 4 (WT) vs. 71 +/- 6 (TIMP-1(-/-)) microl] and LV end-diastolic pressure [9.0 +/- 1.2 (WT) vs. 12.7 +/- 1.4 (TIMP-1(-/-)) mmHg] were significantly increased in the TIMP-1(-/-) mice 2 wk after MI. LV contractility was reduced to a similar degree in the WT and TIMP-1(-/-) groups after MI, as indicated by a significant fall in the LV end-systolic pressure-volume relationship. Ventricular weight and cross-sectional areas of LV myocytes were significantly increased in TIMP-1(-/-) mice, indicating that the hypertrophic response was more pronounced. The observed significant loss of fibrillar collagen in the TIMP-1(-/-) controls may have been an important contributory factor for the observed LV alterations in the TIMP-1(-/-) mice after MI. These findings demonstrate that TIMP-1 deficiency amplifies adverse LV remodeling after MI in mice and emphasizes the importance of local endogenous control of cardiac MMP activity by TIMP-1.
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Affiliation(s)
- Esther E J M Creemers
- Department of Pathology, Cardiovascular Research Institute Maastricht, University of Maastricht, The Netherlands
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Reconciling Clinical Criteria and the Use of Genetically Engineered Animals in Sepsis Research. Intensive Care Med 2003. [DOI: 10.1007/978-1-4757-5548-0_4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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