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Hassanzadeh-Taheri M, Mohammadifard M, Erfanian Z, Hosseini M. The maternal reduced uteroplacental perfusion model of preeclampsia induces sexually dimorphic metabolic responses in rat offspring. Biol Sex Differ 2022; 13:48. [PMID: 36109770 PMCID: PMC9479437 DOI: 10.1186/s13293-022-00458-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/04/2021] [Accepted: 08/31/2022] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Offspring born to preeclamptic mothers are prone to obesity, diabetes and hypertension in later life, but still, studies investigating the underlying mechanism are limited. Here, we aimed to investigate the impact of the reduced uteroplacental perfusion (RUPP) rat preeclampsia model on offspring metabolic outcomes. METHODS Timed pregnant Wistar rats underwent RUPP or sham surgeries on day 14 of gestation. Glucometabolic parameters were evaluated on postnatal days (PND), 14 (childhood), and 60 (young adult). In addition, intraperitoneal glucose tolerance test (IPGTT), homeostatic model assessment of insulin resistance (HOMA-IR), immunohistochemical staining for insulin in pancreatic islets, arterial blood pressure and 24-h urine protein (24hUP) excretion were performed at PND60. RESULTS Male, but not female, young adult rats (PND60) of RUPP dams exhibited an impaired IPGTT, decreased circulatory insulin and weakened pancreatic insulin immunoreactivity. Compared to the male offspring of the sham group, the body mass of male RUPP offspring significantly caught up after PND42, but it was not sex-specific. RUPP pups also exhibited upregulations in glucagon (only males) and ghrelin (both sexes with a more significant increase in males) during PND14-PND60. However, in sham offspring (both sexes), glucagon levels were downregulated and ghrelin levels unchanged during PND14-PND60. The blood pressure, HOMA-IR and 24hUP values did not alter in RUPP pups. CONCLUSIONS The overall results suggest that maternal RUPP has negative and sex-specific impacts on insulin, glucagon and ghrelin regulations in offspring and that, as young adults, male RUPP rats may be more prone to develop obesity and diabetes.
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Affiliation(s)
- Mohammadmehdi Hassanzadeh-Taheri
- Cellular and Molecular Research Center, Department of Anatomical Sciences, Birjand University of Medical Sciences, Birjand, Iran
| | - Mahtab Mohammadifard
- Department of Pathology, Faculty of Medicine, Birjand University of Medical Sciences, Birjand, Iran
| | - Zahra Erfanian
- Faculty of Medicine, Birjand University of Medical Sciences, Birjand, Iran
| | - Mehran Hosseini
- Cellular and Molecular Research Center, Department of Anatomical Sciences, Birjand University of Medical Sciences, Birjand, Iran.
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2
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Quick S, Procter TV, Moss J, Seeker L, Walton M, Lawson A, Baker S, Beletski A, Garcia DJ, Mohammad M, Mungall W, Onishi A, Tobola Z, Stringer M, Jansen MA, Vallatos A, Giarratano Y, Bernabeu MO, Wardlaw JM, Williams A. Loss of the heterogeneous expression of flippase ATP11B leads to cerebral small vessel disease in a normotensive rat model. Acta Neuropathol 2022; 144:283-303. [PMID: 35635573 PMCID: PMC9288385 DOI: 10.1007/s00401-022-02441-4] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2022] [Revised: 05/18/2022] [Accepted: 05/18/2022] [Indexed: 01/20/2023]
Abstract
Cerebral small vessel disease (SVD) is the leading cause of vascular dementia, causes a quarter of strokes, and worsens stroke outcomes. The disease is characterised by patchy cerebral small vessel and white matter pathology, but the underlying mechanisms are poorly understood. This microvascular and tissue damage has been classically considered secondary to extrinsic factors, such as hypertension, but this fails to explain the patchy nature of the disease, the link to endothelial cell (EC) dysfunction even when hypertension is absent, and the increasing evidence of high heritability to SVD-related brain damage. We have previously shown the link between deletion of the phospholipase flippase Atp11b and EC dysfunction in an inbred hypertensive rat model with SVD-like pathology and a single nucleotide polymorphism (SNP) in ATP11B associated with human sporadic SVD. Here, we generated a novel normotensive transgenic rat model, where Atp11b is deleted, and show pathological, imaging and behavioural changes typical of those in human SVD, but that occur without hypertension. Atp11bKO rat brain and retinal small vessels show ECs with molecular and morphological changes of dysfunction, with myelin disruption in a patchy pattern around some but not all brain small vessels, similar to the human brain. We show that ATP11B/ATP11B is heterogeneously expressed in ECs in normal rat and human brain even in the same transverse section of the same blood vessel, suggesting variable effects of the loss of ATP11B on each vessel and an explanation for the patchy nature of the disease. This work highlights a link between inherent EC dysfunction and vulnerability to SVD white matter damage with a marked heterogeneity of ECs in vivo which modulates this response, occurring even in the absence of hypertension. These findings refocus our strategies for therapeutics away from antihypertensive (and vascular risk factor) control alone and towards ECs in the effort to provide alternative targets to prevent a major cause of stroke and dementia.
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Affiliation(s)
- Sophie Quick
- Centre for Regenerative Medicine, Institute for Regeneration and Repair, University of Edinburgh, Edinburgh, EH16 4UU, UK
| | - Tessa V Procter
- Centre for Regenerative Medicine, Institute for Regeneration and Repair, University of Edinburgh, Edinburgh, EH16 4UU, UK
| | - Jonathan Moss
- Centre for Regenerative Medicine, Institute for Regeneration and Repair, University of Edinburgh, Edinburgh, EH16 4UU, UK
- UK Dementia Research Institute, University of Edinburgh, Edinburgh, EH16 4SB, UK
| | - Luise Seeker
- Centre for Regenerative Medicine, Institute for Regeneration and Repair, University of Edinburgh, Edinburgh, EH16 4UU, UK
| | - Marc Walton
- Centre for Regenerative Medicine, Institute for Regeneration and Repair, University of Edinburgh, Edinburgh, EH16 4UU, UK
| | - Angus Lawson
- Centre for Regenerative Medicine, Institute for Regeneration and Repair, University of Edinburgh, Edinburgh, EH16 4UU, UK
| | - Serena Baker
- Centre for Regenerative Medicine, Institute for Regeneration and Repair, University of Edinburgh, Edinburgh, EH16 4UU, UK
| | - Anna Beletski
- Centre for Regenerative Medicine, Institute for Regeneration and Repair, University of Edinburgh, Edinburgh, EH16 4UU, UK
| | - Daniela Jaime Garcia
- Centre for Regenerative Medicine, Institute for Regeneration and Repair, University of Edinburgh, Edinburgh, EH16 4UU, UK
| | - Mehreen Mohammad
- UK Dementia Research Institute, University of Edinburgh, Edinburgh, EH16 4SB, UK
| | - William Mungall
- Bioresearch and Veterinary Services, University of Edinburgh, Edinburgh, EH16 4SB, UK
| | - Ami Onishi
- Bioresearch and Veterinary Services, University of Edinburgh, Edinburgh, EH16 4SB, UK
| | - Zuzanna Tobola
- Centre for Clinical Brain Sciences, Edinburgh Imaging, Row Fogo Centre for Research into Ageing and the Brain, University of Edinburgh, Edinburgh, EH16 4SB, UK
| | - Michael Stringer
- Centre for Clinical Brain Sciences, Edinburgh Imaging, Row Fogo Centre for Research into Ageing and the Brain, University of Edinburgh, Edinburgh, EH16 4SB, UK
| | - Maurits A Jansen
- Centre for Cardiovascular Science, University of Edinburgh, Edinburgh, EH16 4SB, UK
| | - Antoine Vallatos
- Centre for Clinical Brain Sciences, Edinburgh Imaging, Row Fogo Centre for Research into Ageing and the Brain, University of Edinburgh, Edinburgh, EH16 4SB, UK
| | - Ylenia Giarratano
- College of Medicine and Veterinary Medicine, College of Science and Engineering, Bayes Centre, Usher Institute, University of Edinburgh, Edinburgh, EH16 4UX, UK
| | - Miguel O Bernabeu
- College of Medicine and Veterinary Medicine, College of Science and Engineering, Bayes Centre, Usher Institute, University of Edinburgh, Edinburgh, EH16 4UX, UK
| | - Joanna M Wardlaw
- Centre for Clinical Brain Sciences, Edinburgh Imaging, Row Fogo Centre for Research into Ageing and the Brain, University of Edinburgh, Edinburgh, EH16 4SB, UK
- UK Dementia Research Institute, University of Edinburgh, Edinburgh, EH16 4SB, UK
| | - Anna Williams
- Centre for Regenerative Medicine, Institute for Regeneration and Repair, University of Edinburgh, Edinburgh, EH16 4UU, UK.
- UK Dementia Research Institute, University of Edinburgh, Edinburgh, EH16 4SB, UK.
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3
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van Ham WB, Kessler EL, Oerlemans MI, Handoko ML, Sluijter JP, van Veen TA, den Ruijter HM, de Jager SC. Clinical Phenotypes of Heart Failure With Preserved Ejection Fraction to Select Preclinical Animal Models. JACC Basic Transl Sci 2022; 7:844-857. [PMID: 36061340 PMCID: PMC9436760 DOI: 10.1016/j.jacbts.2021.12.009] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/18/2021] [Revised: 12/20/2021] [Accepted: 12/31/2021] [Indexed: 11/21/2022]
Abstract
To better define HFpEF clinically, patients are nowadays often clustered into phenogroups, based on their comorbidities and symptoms Many animal models claim to mimic HFpEF, but phenogroups are not yet regularly used to cluster them HFpEF animals models often lack reports of clinical symptoms of HF, therefore mainly presenting as extended models of LVDD, clinically seen as a prestate of HFpEF We investigated if clinically relevant phenogroups can guide selection of animal models aiming at better defined animal research
At least one-half of the growing heart failure population consists of heart failure with preserved ejection fraction (HFpEF). The limited therapeutic options, the complexity of the syndrome, and many related comorbidities emphasize the need for adequate experimental animal models to study the etiology of HFpEF, as well as its comorbidities and pathophysiological changes. The strengths and weaknesses of available animal models have been reviewed extensively with the general consensus that a “1-size-fits-all” model does not exist, because no uniform HFpEF patient exists. In fact, HFpEF patients have been categorized into HFpEF phenogroups based on comorbidities and symptoms. In this review, we therefore study which animal model is best suited to study the different phenogroups—to improve model selection and refinement of animal research. Based on the published data, we extrapolated human HFpEF phenogroups into 3 animal phenogroups (containing small and large animals) based on reports and definitions of the authors: animal models with high (cardiac) age (phenogroup aging); animal models focusing on hypertension and kidney dysfunction (phenogroup hypertension/kidney failure); and models with hypertension, obesity, and type 2 diabetes mellitus (phenogroup cardiometabolic syndrome). We subsequently evaluated characteristics of HFpEF, such as left ventricular diastolic dysfunction parameters, systemic inflammation, cardiac fibrosis, and sex-specificity in the different models. Finally, we scored these parameters concluded how to best apply these models. Based on our findings, we propose an easy-to-use classification for future animal research based on clinical phenogroups of interest.
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Affiliation(s)
- Willem B. van Ham
- Department of Medical Physiology, University Medical Center Utrecht, Utrecht, the Netherlands
| | - Elise L. Kessler
- Laboratory for Experimental Cardiology, Department of Cardiology, University Medical Center Utrecht, Utrecht, the Netherlands
- Utrecht Regenerative Medicine Center, Circulatory Health Laboratory, University of Utrecht, Utrecht, the Netherlands
| | | | - M. Louis Handoko
- Department of Cardiology, Amsterdam University Medical Center, Vrije Universiteit Amsterdam, Amsterdam, the Netherlands
| | - Joost P.G. Sluijter
- Laboratory for Experimental Cardiology, Department of Cardiology, University Medical Center Utrecht, Utrecht, the Netherlands
- Utrecht Regenerative Medicine Center, Circulatory Health Laboratory, University of Utrecht, Utrecht, the Netherlands
| | - Toon A.B. van Veen
- Department of Medical Physiology, University Medical Center Utrecht, Utrecht, the Netherlands
| | - Hester M. den Ruijter
- Laboratory for Experimental Cardiology, Department of Cardiology, University Medical Center Utrecht, Utrecht, the Netherlands
| | - Saskia C.A. de Jager
- Laboratory for Experimental Cardiology, Department of Cardiology, University Medical Center Utrecht, Utrecht, the Netherlands
- Address for correspondence: Dr Saskia C.A. de Jager, Laboratory for Experimental Cardiology, Department of Cardiology, University Medical Center Utrecht, Heidelberglaan 100, Utrecht 3584 CX, the Netherlands.
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Rabaglino MB, Wakabayashi M, Pearson JT, Jensen LJ. Effect of age on the vascular proteome in middle cerebral arteries and mesenteric resistance arteries in mice. Mech Ageing Dev 2021; 200:111594. [PMID: 34756926 DOI: 10.1016/j.mad.2021.111594] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2021] [Revised: 10/11/2021] [Accepted: 10/26/2021] [Indexed: 10/20/2022]
Abstract
Aging is associated with hypertension and brain blood flow dysregulation, which are major risk factors for cardiovascular and neurodegenerative diseases. Structural remodeling, endothelial dysfunction, or hypercontractility of resistance vessels may cause increased total peripheral resistance and hypertension. Recent studies showed that G protein- and RhoA/Rho-kinase pathways are involved in increased mean arterial pressure (MAP) and arterial tone in middle-aged mice. We aimed to characterize the age-dependent changes in the vascular proteome in normal laboratory mice using mass spectrometry and bioinformatics analyses on middle cerebral arteries and mesenteric resistance arteries from young (3 months) vs. middle-aged (14 months) mice. In total, 31 proteins were significantly affected by age whereas 172 proteins were differentially expressed by vessel type. Hierarchical clustering revealed that 207 proteins were significantly changed or clustered by age. Vitamin B6 pathway, Biosynthesis of antibiotics, Regulation of actin cytoskeleton and Endocytosis were the top enriched KEGG pathways by age. Several proteins in the RhoA/Rho-kinase pathway changed in a manner consistent with hypertension and dysregulation of cerebral perfusion. Although aging had a less profound effect than vessel type on the resistance artery proteome, regulation of actin cytoskeleton, including the RhoA/Rho-kinase pathway, is an important target for age-dependent hypertension.
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Affiliation(s)
- Maria Belen Rabaglino
- Dept. of Applied Mathematics and Computer Science, Danish Technical University, Denmark
| | - Masaki Wakabayashi
- Omics Research Center, National Cerebral and Cardiovascular Center, Osaka, Japan
| | - James Todd Pearson
- Dept. of Cardiac Physiology, National Cerebral and Cardiovascular Center Research Institute, Osaka, Japan; Monash Biomedicine Discovery Institute and Department of Physiology, Monash University, Clayton, Australia
| | - Lars Jørn Jensen
- Dept. of Veterinary and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Denmark.
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5
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Nguyen ITN, Brandt MM, van de Wouw J, van Drie RWA, Wesseling M, Cramer MJ, de Jager SCA, Merkus D, Duncker DJ, Cheng C, Joles JA, Verhaar MC. Both male and female obese ZSF1 rats develop cardiac dysfunction in obesity-induced heart failure with preserved ejection fraction. PLoS One 2020; 15:e0232399. [PMID: 32374790 PMCID: PMC7202634 DOI: 10.1371/journal.pone.0232399] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2019] [Accepted: 04/14/2020] [Indexed: 12/11/2022] Open
Abstract
Heart failure with a preserved ejection fraction (HFpEF) is associated with multiple comorbidities, such as old age, hypertension, type 2 diabetes and obesity and is more prevalent in females. Although the male obese ZSF1 rat has been proposed as a suitable model to study the development of diastolic dysfunction and early HFpEF, studies in female animals have not been performed yet. Therefore, we aimed to characterize the cardiac phenotype in female obese ZSF1 rats and their lean counterparts. Additionally, we aimed to investigate whether differences exist in disease progression in obese male and female ZSF1 rats. Therefore, male and female ZSF1 rats, lean as well as obese (N = 6-9/subgroup), were used. Every two weeks, from 12 to 26 weeks of age, systolic blood pressure and echocardiographic measurements were performed, and venous blood was sampled. Female obese ZSF1 rats, as compared to female lean ZSF1 rats, developed diastolic dysfunction with cardiac hypertrophy and fibrosis in the presence of severe dyslipidemia, increased plasma growth differentiation factor 15 and mild hypertension, and preservation of systolic function. Although obese female ZSF1 rats did not develop hyperglycemia, their diastolic dysfunction was as severe as in the obese males. Taken together, the results from the present study suggest that the female obese ZSF1 rat is a relevant animal model for HFpEF with multiple comorbidities, suitable for investigating novel therapeutic interventions.
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Affiliation(s)
- Isabel T. N. Nguyen
- Department of Nephrology and Hypertension, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Maarten M. Brandt
- Division of Experimental Cardiology, Department of Cardiology, Erasmus MC, University Medical Center Rotterdam, Rotterdam, The Netherlands
| | - Jens van de Wouw
- Division of Experimental Cardiology, Department of Cardiology, Erasmus MC, University Medical Center Rotterdam, Rotterdam, The Netherlands
| | - Ruben W. A. van Drie
- Division of Experimental Cardiology, Department of Cardiology, Erasmus MC, University Medical Center Rotterdam, Rotterdam, The Netherlands
| | - Marian Wesseling
- Laboratory of Experimental Cardiology, University Medical Center Utrecht, Utrecht University, Utrecht, The Netherlands
| | - Maarten J. Cramer
- Department of Cardiology, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Saskia C. A. de Jager
- Laboratory of Experimental Cardiology, University Medical Center Utrecht, Utrecht University, Utrecht, The Netherlands
| | - Daphne Merkus
- Division of Experimental Cardiology, Department of Cardiology, Erasmus MC, University Medical Center Rotterdam, Rotterdam, The Netherlands
- Walter Brendel Center of Experimental Medicine (WBex), Munich, Germany
- German Center for Cardiovascular Research (DZHK), Partner Site Munich, Munich Heart Alliance (MHA), Munich, Germany
| | - Dirk J. Duncker
- Division of Experimental Cardiology, Department of Cardiology, Erasmus MC, University Medical Center Rotterdam, Rotterdam, The Netherlands
| | - Caroline Cheng
- Department of Nephrology and Hypertension, University Medical Center Utrecht, Utrecht, The Netherlands
- Division of Experimental Cardiology, Department of Cardiology, Erasmus MC, University Medical Center Rotterdam, Rotterdam, The Netherlands
| | - Jaap. A. Joles
- Department of Nephrology and Hypertension, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Marianne C. Verhaar
- Department of Nephrology and Hypertension, University Medical Center Utrecht, Utrecht, The Netherlands
- * E-mail:
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6
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Kooiman J, Terstappen F, van Wagensveld L, Franx A, Wever KE, Roseboom TJ, Joles JA, Gremmels H, Lely AT. Conflicting Effects of Fetal Growth Restriction on Blood Pressure Between Human and Rat Offspring: A Meta-Analysis. Hypertension 2020; 75:806-818. [PMID: 31983304 DOI: 10.1161/hypertensionaha.119.14111] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Low birth weight is associated with hypertension. Low birth weight can result from fetal growth restriction (FGR) or prematurity. FGR is postulated to impact blood pressure (BP) by developmental programming. This systematic review and meta-analysis studies BP in human and animal offspring following FGR. Pubmed and Web of Science were searched for studies reporting on BP after placental insufficiency induced FGR compared with normal growth controls. Primary outcome was mean absolute BP difference (ΔBP mm Hg [95% CI]). Meta-analysis was performed using random-effects models. Subgroup analyses were executed on species, sex, age, pregnancy duration, and stress during BP readings. Due to large interspecies heterogeneity, analyses were performed separately for human (n=41) and animal (n=31) studies, the latter restricted to rats (n=27). Human studies showed a ΔBP between FGR and controls of -0.6 mm Hg ([95% CI, -1.7 to 0.6]; I2=91%). Mean ΔBP was -2.6 mm Hg (95% CI, -5.7 to 0.4) in women versus -0.5 mm Hg (95% CI, -3.7 to 2.7) in men. Subgroup analyses did not indicate age, gestational age, and stress during measurements as sources of heterogeneity. In rats, mean BP was 12.0 mm Hg ([95% CI, 8.8-15.2]; I2=81%) higher in FGR offspring. This difference was more pronounced in FGR males (13.6 mm Hg [95% CI, 10.3-17.0] versus 9.1 mm Hg [95% CI, 5.3-12.8]). Subgroup analyses on age showed no statistical interaction. BP readings under restrained conditions resulted in larger BP differences between FGR and control rats (15.3 mm Hg [95% CI, 11.6-18.9] versus 5.7 mm Hg [95% CI, 1.1-10.3]). Rat studies confirm the relation between FGR and offspring BP, while observational studies in humans do not show such differences. This may be due to the observational nature of human studies, methodological limitations, or an absence of this phenomenon in humans. Clinical Trial Registration URL: http://www.clinicaltrials.gov. Unique identifier: CRD42018091819.
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Affiliation(s)
- Judith Kooiman
- From the Department of Obstetrics (J.K., F.T., L.v.W., A.F., A.T.L.), University Medical Center Utrecht, the Netherlands
| | - Fieke Terstappen
- From the Department of Obstetrics (J.K., F.T., L.v.W., A.F., A.T.L.), University Medical Center Utrecht, the Netherlands.,Department of Developmental Origin of Disease (F.T.), University Medical Center Utrecht, the Netherlands
| | - Lilian van Wagensveld
- From the Department of Obstetrics (J.K., F.T., L.v.W., A.F., A.T.L.), University Medical Center Utrecht, the Netherlands
| | - Arie Franx
- From the Department of Obstetrics (J.K., F.T., L.v.W., A.F., A.T.L.), University Medical Center Utrecht, the Netherlands
| | - Kimberley E Wever
- Systematic Review Center for Laboratory animal Experimentation (SYRCLE), Department for Health Evidence, Radboud University Medical Center, Nijmegen, the Netherlands (K.E.W.)
| | - Tessa J Roseboom
- Department of Clinical Epidemiology, Biostatistics and Bioinformatics, Obstetrics and Gynecology, Amsterdam Public Health Research Institute, Amsterdam Reproduction and Development Research Institute, Amsterdam UMC, University of Amsterdam, the Netherlands (T.J.R.)
| | - Jaap A Joles
- Wilhelmina Children's Hospital and Department of Nephrology and Hypertension (J.A.J., H.G.), University Medical Center Utrecht, the Netherlands
| | - Hendrik Gremmels
- Wilhelmina Children's Hospital and Department of Nephrology and Hypertension (J.A.J., H.G.), University Medical Center Utrecht, the Netherlands
| | - A Titia Lely
- From the Department of Obstetrics (J.K., F.T., L.v.W., A.F., A.T.L.), University Medical Center Utrecht, the Netherlands
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7
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Willeman MN, Chawla MK, Zempare MA, Biwer LA, Hoang LT, Uprety AR, Fitzhugh MC, De Both M, Coleman PD, Trouard TP, Alexander GE, Mitchell KD, Barnes CA, Hale TM, Huentelman M. Gradual hypertension induction in middle-aged Cyp1a1-Ren2 transgenic rats produces significant impairments in spatial learning. Physiol Rep 2019; 7:e14010. [PMID: 30916484 PMCID: PMC6436186 DOI: 10.14814/phy2.14010] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2018] [Revised: 12/16/2018] [Accepted: 12/18/2018] [Indexed: 12/30/2022] Open
Abstract
Hypertension is a major health concern in the developed world, and its prevalence increases with advancing age. The impact of hypertension on the function of the renal and cardiovascular systems is well studied; however, its influence on the brain regions important for cognition has garnered less attention. We utilized the Cyp1a1-Ren2 xenobiotic-inducible transgenic rat model to mimic both the age of onset and rate of induction of hypertension observed in humans. Male, 15-month-old transgenic rats were fed 0.15% indole-3-carbinol (I3C) chow to slowly induce renin-dependent hypertension over a 6-week period. Systolic blood pressure significantly increased, eventually reaching 200 mmHg by the end of the study period. In contrast, transgenic rats fed a control diet without I3C did not show significant changes in blood pressure (145 mmHg at the end of study). Hypertension was associated with cardiac, aortic, and renal hypertrophy as well as increased collagen deposition in the left ventricle and kidney of the I3C-treated rats. Additionally, rats with hypertension showed reduced savings from prior spatial memory training when tested on the hippocampus-dependent Morris swim task. Motor and sensory functions were found to be unaffected by induction of hypertension. Taken together, these data indicate a profound effect of hypertension not only on the cardiovascular-renal axis but also on brain systems critically important for learning and memory. Future use of this model and approach may empower a more accurate investigation of the influence of aging on the systems responsible for cardiovascular, renal, and neurological health.
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Affiliation(s)
- Mari N. Willeman
- Evelyn F. McKnight Brain InstituteUniversity of ArizonaTucsonArizona
- Neurogenomics DivisionThe Translational Genomics Research Institute (TGen)PhoenixArizona
- Arizona Alzheimer's ConsortiumPhoenixArizona
| | - Monica K. Chawla
- Evelyn F. McKnight Brain InstituteUniversity of ArizonaTucsonArizona
- Arizona Alzheimer's ConsortiumPhoenixArizona
| | - Marc A. Zempare
- Evelyn F. McKnight Brain InstituteUniversity of ArizonaTucsonArizona
- Arizona Alzheimer's ConsortiumPhoenixArizona
| | - Lauren A Biwer
- Department of Basic Medical SciencesUniversity of ArizonaCollege of Medicine – PhoenixPhoenixArizona
| | - Lan T. Hoang
- Evelyn F. McKnight Brain InstituteUniversity of ArizonaTucsonArizona
- Arizona Alzheimer's ConsortiumPhoenixArizona
| | - Ajay R. Uprety
- Evelyn F. McKnight Brain InstituteUniversity of ArizonaTucsonArizona
- Arizona Alzheimer's ConsortiumPhoenixArizona
| | - Megan C. Fitzhugh
- Evelyn F. McKnight Brain InstituteUniversity of ArizonaTucsonArizona
- Arizona Alzheimer's ConsortiumPhoenixArizona
- Department of PsychologyUniversity of ArizonaTucsonArizona
| | - Matthew De Both
- Neurogenomics DivisionThe Translational Genomics Research Institute (TGen)PhoenixArizona
- Arizona Alzheimer's ConsortiumPhoenixArizona
| | - Paul D. Coleman
- Arizona Alzheimer's ConsortiumPhoenixArizona
- Center for Neurodegenerative Disease ResearchBiodesign InstituteArizona State UniversityTempeArizona
| | - Theodore P. Trouard
- Evelyn F. McKnight Brain InstituteUniversity of ArizonaTucsonArizona
- Department of Biomedical Engineering and Medical ImagingUniversity of ArizonaTucsonArizona
| | - Gene E. Alexander
- Evelyn F. McKnight Brain InstituteUniversity of ArizonaTucsonArizona
- Arizona Alzheimer's ConsortiumPhoenixArizona
- Department of PsychologyUniversity of ArizonaTucsonArizona
- Neuroscience and Physiological Sciences Graduate Interdisciplinary ProgramsUniversity of ArizonaTucsonArizona
| | - Kenneth D. Mitchell
- Department of PhysiologyTulane University Health Sciences CenterNew OrleansLos Angeles
| | - Carol A. Barnes
- Evelyn F. McKnight Brain InstituteUniversity of ArizonaTucsonArizona
- Arizona Alzheimer's ConsortiumPhoenixArizona
- Department of PsychologyUniversity of ArizonaTucsonArizona
| | - Taben M. Hale
- Department of Basic Medical SciencesUniversity of ArizonaCollege of Medicine – PhoenixPhoenixArizona
| | - Matthew Huentelman
- Evelyn F. McKnight Brain InstituteUniversity of ArizonaTucsonArizona
- Neurogenomics DivisionThe Translational Genomics Research Institute (TGen)PhoenixArizona
- Arizona Alzheimer's ConsortiumPhoenixArizona
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8
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Abstract
Neonatal nephron loss may follow hypoxic-ischemic events or nephrotoxic medications. Its long-term effects on the kidney are still unclear. Unlike term infants, preterm neonates less than 36 weeks gestational age show ongoing nephrogenesis. We hypothesized that nephron loss during nephrogenesis leads to more severe renal sequelae than nephron loss shortly after the completion of nephrogenesis. Rats show nephrogenesis until day 10 of life resembling the situation of preterm infants. Animals were uninephrectomized at day 1 (UNX d1) resulting in nephron reduction during nephrogenesis and at day 14 of life (UNX d14) inducing nephron loss after the completion of nephrogenesis. 28 days after uninephrectomy the compensatory renal growth was higher in UNX d1 compared to UNX d14. Nephrin was reduced and collagen deposition increased in UNX d1. At 1 year of age, glomerulosclerosis and markers of tubulointerstitial damage were most prevalent in UNX d1. Moreover, the number of desmin-positive podocytes was higher and nephrin was reduced in UNX d1 indicating podocyte damage. Infiltration of inflammatory cells was heightened after UNX d1. Uninephrectomized animals showed no arterial hypertension. We conclude that neonatal nephron loss during active nephrogenesis leads to more severe glomerular and tubulointerstitial damage, which is not a consequence of compensatory arterial hypertension.
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9
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Perez SD, Silva D, Millar AB, Molinaro CA, Carter J, Bassett K, Lorton D, Garcia P, Tan L, Gross J, Lubahn C, Thyagarajan S, Bellinger DL. Sympathetic innervation of the spleen in male Brown Norway rats: a longitudinal aging study. Brain Res 2009; 1302:106-17. [PMID: 19748498 DOI: 10.1016/j.brainres.2009.09.012] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2009] [Revised: 09/02/2009] [Accepted: 09/04/2009] [Indexed: 12/27/2022]
Abstract
Aging leads to reduced cellular immunity with consequent increased rates of infectious disease, cancer, and autoimmunity in the elderly. The sympathetic nervous system (SNS) modulates innate and adaptive immunity via innervation of lymphoid organs. In aged Fischer 344 (F344) rats, noradrenergic (NA) nerve density in secondary lymphoid organs declines, which may contribute to immunosenescence with aging. These studies suggest there is SNS involvement in age-induced immune dysregulation. The purpose of this study was to longitudinally characterize age-related change in sympathetic innervation of the spleen and sympathetic activity/tone in male Brown Norway (BN) rats, which live longer and have a strikingly different immune profile than F344 rats, the traditional animal model for aging research. Splenic sympathetic neurotransmission was evaluated between 8 and 32 months of age by assessing (1) NA nerve fiber density, (2) splenic norepinephrine (NE) concentration, and (3) circulating catecholamine levels after decapitation. We report a decline in NA nerve density in splenic white pulp (45%) at 15 months of age compared with 8-month-old (M) rats, which is followed by a much slower rate of decline between 24 and 32 months. Lower splenic NE concentrations between 15 and 32 months of age compared with 8M rats were consistent with morphometric findings. Circulating catecholamine levels after decapitation stress generally dropped with increasing age. These findings suggest there is a sympathetic-to-immune system dysregulation beginning at middle age. Given the unique T-helper-2 bias in BN rats, altered sympathetic-immune communication may be important for understanding the age-related rise in asthma and autoimmunity.
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Affiliation(s)
- Sam D Perez
- Department of Physiology and Pharmacology, Loma Linda University School of Medicine, Loma Linda, CA 92350, USA
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10
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Yang HT, Chou HJ, Han BC, Huang SY. Lifelong inorganic arsenic compounds consumption affected blood pressure in rats. Food Chem Toxicol 2007; 45:2479-87. [PMID: 17688991 DOI: 10.1016/j.fct.2007.05.024] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2006] [Revised: 04/16/2007] [Accepted: 05/23/2007] [Indexed: 11/24/2022]
Abstract
Chronic arsenic exposure is a known risk factor for cardiovascular disease and has a strong correlation with hypertension. Oxidative stress may be one of the major contributors to arsenic-induced hypertension. To investigate the antioxidative and CYP systems through which inorganic arsenic compounds may contribute to blood pressure elevation in rats, we administered 50ppm arsenic (as arsenite and arsenate) in drinking water to Wistar rats for 200 successive days. Systolic blood pressure was determined every 20 days, and blood samples and tissues were collected at each time point for biological analysis. Compared to the control group, weight gain in the arsenic-exposed animals was slightly but significantly lower, whereas the relative weights of the various tissues was higher. Blood pressure was elevated until day 80 in both arsenic groups followed by a time-dependent change in the antioxidative enzyme system. The hypertensive effect remained until day 200 for arsenite when the change by arsenate was minimized. Patterns of antioxidative enzyme change differed between arsenite and arsenate. However, the most common marker of hypertension, the angiotensin-converting enzyme, showed no significant change in either arsenic group. CYP4A was highly expressed in both arsenic groups, particularly in the arsenite group. These results indicate that low but chronic arsenic exposure might cause elevated blood pressure and antioxidative interference. Furthermore, CYP4A might be more important than ACE in contributing to arsenic-induced hypertension.
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Affiliation(s)
- Hui-Ting Yang
- School of Pharmaceutical Science, Taipei Medical University, Taipei 110, Taiwan
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11
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Li M, Ratcliffe SJ, Knoll F, Wu J, Ances B, Mardini W, Floyd TF. Aging: Impact Upon Local Cerebral Oxygenation and Blood Flow With Acute Isovolemic Hemodilution. J Neurosurg Anesthesiol 2006; 18:125-31. [PMID: 16628066 DOI: 10.1097/00008506-200604000-00006] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Data from the neurosurgical critical care arena demonstrate a correlation between cerebral oxygenation, survival, and cognitive function. Transfusion may increase and hemodilution decrease cerebral oxygenation. Both acute and chronic anemia have been associated with cognitive dysfunction. Aggressive blood conservation protocols have been instituted across all age groups without conclusive evidence for their impact upon outcome. Aged subjects are at the greatest risk of cognitive sequelae after major surgery associated with significant blood loss. We hypothesize that cerebral physiologic changes associated with "normal" aging may compromise cerebral oxygenation in the presence of severe anemia.Fischer 344 rats, the NIH National Institute of Aging normal aging rat model, underwent a stepwise isovolemic hemodilution protocol. Age groups (Age Grp) studied were as follows: Age Grp-A (3 months), n=14; Age Grp-B (9 to 12 months), n=14; and Age Grp-C (24 months), n=14. Brain oxygen tension (PBrO2), laser Doppler flow, and mean arterial pressure were measured. Final hemoglobin averaged 6.1+/-0.9 g/dL. PBrO2 levels decreased from a baseline of 18.1+/-4.1 to 17.5+/-6.8 mm Hg (P=0.49), and laser Doppler flow increased by 18+/-20% (P<0.0001) after hemodilution. Employing repeated measures multiple regression, Age Grp (P=0.30) was not a significant controlling covariate of PBrO2 in response to isovolemic hemodilution. PBrO2 levels were actually higher in Age Grp-C animals at all time points of the hemodilution protocol, although this was not statistically significant. Aged animals were also fully capable of mounting a robust local cerebral hyperemic response to the anemic challenge that was not separable from the response of younger animals.
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Affiliation(s)
- Min Li
- Department of Anesthesiology and Critical Care, Hospital of the University of Pennsylvania, 3400 Spruce Street, Philadelphia, PA 19104, USA
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12
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Simon G, Danneman KJ. Dilation and reduced distensibility of rat carotid artery with aging. Clin Exp Hypertens 2005; 27:459-66. [PMID: 16081338 DOI: 10.1081/ceh-200067652] [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: 11/03/2022]
Abstract
To better understand the pathogenesis of increased arterial stiffening with aging, the relative contribution of geometry (lumen diameter) and stiffening of wall components (elastic modulus) to reduced distensibility of rat carotid artery in the early stages of aging was investigated. Pressure-volume (distensibility) relationships were measured in excised, in vitro perfused right carotid artery of 7-. 10- and 20-month old, male Sprague-Dawley rats. The left carotid artery of rats was perfusion-fixed in situ at 100 mm Hg and then embedded in epoxy for morphometric measurements. Compared to 7- and 10-month old rats, there was dilation (increased lumen diameter), increased wall thickness, and reduced distensibility and unchanged elastic moduli of carotid artery in 20-month old rats. Dilation (with early recruitment of collagen fibrils during pressure rise) rather than increased stiffness of wall components appears to be the cause of reduced distensibility of rat carotid artery in the early stages of aging.
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Affiliation(s)
- Geza Simon
- Department of Medicine, VA Medical Center, Minneapolis, Minnesota 55417, USA.
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13
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Abstract
OBJECTIVE Inherited differences in renal function underlie the effect of high salt diets on blood pressure in Dahl rats. We probed the kidneys of inbred Dahl SS/Jr and SR/Jr for anonymous and candidate genes whose expression was regulated by dietary sodium. METHODS mRNA quantitation of both candidate genes implicated in sodium excretion and anonymous gene products found by differential hybridization in the kidneys of salt-resistant (SR) and salt sensitive (SS) inbred Dahl rats on high and low salt diets for 21 days. RESULTS Differential screening revealed a cDNA clone (H1) that showed increased dietary salt-dependent expression only in SS rats. Sequencing of the H1 cDNA showed it was the Dahl rat homologue to a perchloric acid soluble protein expressed in liver and kidney. Among candidate genes, transcript levels of arginosuccinate synthetase (AS) and arginosuccinate lyase (AL) were higher in SS on low salt diets, and AS mRNA increased in response to a high salt diet in SR. Renal mRNA for the ANP-A and the vasopressin type II receptors did not differ by strain or dietary conditions. CONCLUSIONS Three new salt-sensitive genes were detected in the kidneys of inbred Dahl rats. Two genes encode enzymes in the biosynthesis of L-arginine. The upregulation of these genes by dietary salt indicates increased demand and biosynthesis of L-arginine in Dahl SS rats. A third gene encodes a small acid-soluble protein thought to influence the transcription/translation of numerous genes. Further studies will be needed to determine the nature of the association of these genes with salt-sensitivity and blood pressure.
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Affiliation(s)
- Geoffrey K Lighthall
- Department of Physiology and Medicine, University of Maryland, Veterans Administration Medical Center, Baltimore, Maryland 21201, USA
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14
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Aileru AA, Logan E, Callahan M, Ferrario CM, Ganten D, Diz DI. Alterations in Sympathetic Ganglionic Transmission in Response to Angiotensin II in (mRen2)27 Transgenic Rats. Hypertension 2004; 43:270-5. [PMID: 14732737 DOI: 10.1161/01.hyp.0000112422.81661.f3] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Hypertension in (mRen2)27 transgenic rats is partly dependent on activation of the sympathetic nervous system, but the role of ganglionic transmission is unknown. We assessed indices of synaptic plasticity (post-tetanic short-term potentiation [PTP] and long-term potentiation [LTP]) and sympathetic ganglionic transmission without tetany in superior cervical ganglia (SCG) of Hannover Sprague-Dawley rats (HnSD) versus (mRen2)27 rats. There were no differences in decay time constants [PTP=9 minutes; LTP=120 to 150 minutes in both (mRen2)27 and HnSD]. However, angiotensin (Ang) II increased PTP and LTP in SCG isolated from (mRen2)27 rats to a greater extent than HnSD. Candesartan (an AT
1
antagonist) blocked the potentiation in both groups. Without a preceding tetanic pulse, 16-nM Ang II induced similar significant increases in ganglionic transmission of ≈14% in both strains. Assessment of Ang II receptors by
125
I-[Sar
1
Thr
8
]-Ang II binding showed that the AT
1
-receptor subtype predominates in the ganglia. The density of receptors in the SCG was comparable in (mRen2)27 and HnSD rats, whether measured in tissue from ganglia removed and frozen versus ganglia used in the transmission testing, suggesting that upregulation of receptors in vitro after removal of SCG did not occur. The divergence of effects of Ang II on LTP and PTP [greater in (mRen2)27 than HnSD] and nontetany ganglionic transmission (similar in both strains) may reflect different locations of receptors (pre- versus postsynaptic) or different signaling mechanisms involved in the two responses. We suggest that functional Ang II receptors in SCG mediate physiological actions of Ang II on ganglionic transmission and may play a pivotal role in hypertension.
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Affiliation(s)
- Azeez A Aileru
- Biomedical Research Infrastructure Center, Winston-Salem State University, 115 S Chestnut St, Winston-Salem, NC 27101, USA.
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Saupe KW, Sobol SC, Koh SG, Apstein CS. Effects of AT1 Receptor Block Begun Late in Life on Normal Cardiac Aging in Rats. J Cardiovasc Pharmacol 2003; 42:573-80. [PMID: 14508245 DOI: 10.1097/00005344-200310000-00017] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
The goal of this study was to determine how short-term (12 weeks) angiotensin type I (AT1) block begun late in life affects aspects of myocardial biology and physiologic function altered by normal aging. Exercise capacity, myocardial morphology, histopathology, and coronary vascular function (degree of coronary vasodilation in response to adenosine) were evaluated in 53 Fischer 344 rats. Adult (6 months of age) and old (21 months of age) rats were studied after 12 weeks of either control drinking water, a low dose of candesartan that did not significantly lower blood pressure (1 mg/kg/d), or a high dose of candesartan (10 mg/kg/d). Significant age-associated changes in exercise capacity (38% decrease), coronary dilation in response to adenosine (41% decrease), and histopathology occurred but were not affected by candesartan treatment. Age-associated myocardial hypertrophy occurred as indicated by an increase in heart weight-to-tibia length ratio from 0.27 g/cm +/- 0.01 in the adult controls to 0.34 g/cm +/- 0.02 in the old controls (P < 0.05). This hypertrophy in the aged hearts was significantly attenuated by both low-dose (0.30 g/cm +/- 0.01) and high-dose (0.29 g/cm +/- 0.01) candesartan (P < 0.05). Echocardiographic measurements indicate that the candesartan-induced decrease in hypertrophy occurred concomitantly with slight decreases in septal wall thickness and left ventricular (LV) chamber diameter. It is concluded that short-term AT1 block, even when initiated late in life, can decrease age-associated LV hypertrophy independent of blood pressure-lowering effects.
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Affiliation(s)
- Kurt W Saupe
- Cardiovascular Medicine Section, Department of Medicine, University of Wisconsin, Madison, Wisconsin 53706, USA.
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16
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17
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Sofola OA, Knill A, Hainsworth R, Drinkhill M. Change in endothelial function in mesenteric arteries of Sprague-Dawley rats fed a high salt diet. J Physiol 2002; 543:255-60. [PMID: 12181296 PMCID: PMC2290484 DOI: 10.1113/jphysiol.2002.022277] [Citation(s) in RCA: 95] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
A high salt diet in some species results in elevated arterial blood pressure and alterations in vascular smooth muscle responses to agonists. Weanling male Sprague-Dawley rats were given either a high salt diet containing 8 % or a low salt diet of 0.4 % sodium chloride for a period of 4 weeks. At the end of the feeding period, tail systolic pressure was higher in the high salt than in low salt rats. The rats were then killed and the intestines removed. Vascular smooth muscle (VSM) responses were estimated from the changes in lumenal diameter of pressurised second order mesenteric resistance arteries. High salt diet resulted in enhanced VSM responses to noradrenaline. The vessels dilated in response both to acetylcholine and to sodium nitroprusside and the responses were similar in vessels from both high and low salt rats. However, vessels from high salt rats were resistant to the blocking of endothelium derived nitric oxide (EDNO) with L-NAME and the responses were instead abolished by blocking endothelium derived hyperpolarising factor (EDHF) with apamin and charybdotoxin. These results show that in Sprague-Dawley rats, a high salt diet enhances the vasoconstriction in response to noradrenaline. The vasodilatory responses to acetylcholine were not significantly changed. However, they appeared to be mediated mainly by EDHF rather than by EDNO as in the low salt animals.
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Affiliation(s)
- O A Sofola
- Institute for Cardiovascular Research, University of Leeds, Leeds LS2 9JT, UK
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18
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Aileru AA, De Albuquerque A, Hamlyn JM, Manunta P, Shah JR, Hamilton MJ, Weinreich D. Synaptic plasticity in sympathetic ganglia from acquired and inherited forms of ouabain-dependent hypertension. Am J Physiol Regul Integr Comp Physiol 2001; 281:R635-44. [PMID: 11448869 DOI: 10.1152/ajpregu.2001.281.2.r635] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Altered sympathetic nervous system activity has been implicated often in hypertension. We examined short-term potentiation [posttetanic potentiation (PTP)] and long-term potentiation (LTP) in the isolated superior cervical ganglia (SCG) from Sprague-Dawley (SD) rats given vehicle, digoxin, or ouabain by subcutaneous implants as well as in animals with ouabain-induced hypertension (OHR), and inbred Baltimore ouabain-resistant (BOR) and Baltimore ouabain-sensitive (BOS) strains of rats. Postganglionic compound action potentials (CAP) were used to determine PTP and LTP following a tetanic stimulus (20 Hz, 20 s). Baseline CAP magnitude was greater in ganglia from OHR than in vehicle-treated SD rats before tetanus, but the decay time constant of PTP was significantly decreased in OHR and in rats infused with digoxin that were normotensive. In hypertensive BOS and OHR, the time constants for the decay of both PTP and LTP (t(L)) were increased and correlated with blood pressure (slope = 0.15 min/mmHg, r = 0.52, P < 0.047 and 6.7 min/mmHg, r = 0.906, P < 0.0001, respectively). In BOS and OHR, t(L) (minutes) was 492 +/- 40 (n = 7) and 539 +/- 41 (n = 5), respectively, and differed (P < 0.05) from BOR (257 +/- 48, n = 4), SD vehicle rats (240 +/- 18, n = 4), and captopril-treated OHR (370 +/- 52, n = 5). After the tetanus, the CAP at 90 min in BOS and OHR SCG declined less rapidly vs. SD vehicle rats or BOR. Captopril normalized blood pressure and t(L) in OHR. We conclude that the duration of ganglionic LTP and blood pressure are tightly linked in ouabain-dependent hypertension. Our results favor the possibility that enhanced duration of LTP in sympathetic neurons contributes to the increase in sympathetic nerve activity in ouabain-dependent hypertension and suggest that a captopril-sensitive step mediates the link of ouabain with LTP.
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Affiliation(s)
- A A Aileru
- Department of Pharmacology, University of Maryland School of Medicine, 685 West Baltimore St., Baltimore, MD 21201-1559, USA
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Michalkiewicz M, Michalkiewicz T, Kreulen DL, McDougall SJ. Increased blood pressure responses in neuropeptide Y transgenic rats. Am J Physiol Regul Integr Comp Physiol 2001; 281:R417-26. [PMID: 11448843 DOI: 10.1152/ajpregu.2001.281.2.r417] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Considering the coexistence of neuropeptide Y (NPY) and norepinephrine in perivascular sympathetic nerves and the known vasoconstrictor cooperation of NPY with norepinephrine, we investigated the involvement of NPY in long-term control of cardiovascular functions using NPY transgenic (NPY-tg) rats. These rats were developed by injection of the rat (Sprague-Dawley) pronuclei with a 14.5-kb clone of the rat structural NPY gene. When compared with nontransgenic littermates, NPY concentrations were significantly increased in a number of cardiovascular tissues of NPY-tg hemizygotes. Direct basal mean arterial pressure and heart rate were not changed, but calculated total vascular resistance was significantly increased in NPY-tg subjects. Arterial pressure increases, in response to norepinephrine injection, were greater in the NPY-tg rats. Also, the hypotension and bradycardia in response to hemorrhage were significantly reduced in NPY-tg subjects. These results indicate that NPY, when expressed in increased amounts, potentiates the pressor effects of norepinephrine and contributes to maintaining blood pressure during hemorrhage, but it does not alter resting blood pressure. These transgenic rats will facilitate studies of the role of NPY signaling in cardiovascular regulation, particularly regarding its functional cooperation with norepinephrine.
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Affiliation(s)
- M Michalkiewicz
- Department of Physiology, West Virginia University, Morgantown, WV 26506-9229, USA
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20
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Harder T, Plagemann A, Rohde W, Dörner G. Syndrome X-like alterations in adult female rats due to neonatal insulin treatment. Metabolism 1998; 47:855-62. [PMID: 9667235 DOI: 10.1016/s0026-0495(98)90126-3] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Hypothalamic structures are decisively involved in the regulation of body weight and metabolism. In syndrome X, complex metabolic alterations are present, which in women are found to be associated with disturbances of reproductive function and altered androgen levels. In previous experiments in rats, it was shown that a temporary intrahypothalamic hyperinsulinism during early life predisposes to overweight and diabetogenic disturbances later in life, associated with disorganization of hypothalamic regulatory centers. To investigate the possible long-term consequences of elevated peripheral insulin levels during ontogenesis, the following experiment was performed. Newborn female Wistar rats were treated during neonatal life with daily subcutaneous injections of long-acting insulin ([IRI group] 0.3 IU on days 8 and 9 of life and 0.1 IU on days 10 and 11 of life), whereas control animals (CO) received daily NaCl injections. This temporary exposure to increased insulin levels during a critical developmental period resulted in an increased body weight gain including juvenile life and adulthood (P < .01), accompanied by hyperinsulinemia (P < .01), impaired glucose tolerance (P < .05), and increased systolic blood pressure in adulthood (P < .025). No significant alterations were detected either in cyclicity and fertility or in the levels of testosterone, androstenedione, or dehydroepiandrosterone (DHEA) in IRI rats. Morphometric evaluation of hypothalamic nuclei showed a reduced numerical density of neurons (P < .025) and a decreased neuronal volume density (P < .025) within the ventromedial hypothalamic nucleus (VMN) of the IRI rats, whereas the antagonistic lateral hypothalamic area (LHA) was morphometrically unchanged. Newborn offspring of IRI rats (F1 generation) were overweight (P < .05) and had an increased pancreatic insulin concentration (P < .02). In conclusion, perinatal hyperinsulinism seems to predispose to the later development of syndrome X-like changes in female rats, possibly due to impaired organization of hypothalamic regulators of body weight and metabolism.
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Affiliation(s)
- T Harder
- Institute of Experimental Endocrinology, Humboldt University Medical School (Charité), Berlin, Germany
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21
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Arribas SM, Vila E, McGrath JC. Impairment of vasodilator function in basilar arteries from aged rats. Stroke 1997; 28:1812-20. [PMID: 9303030 DOI: 10.1161/01.str.28.9.1812] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
BACKGROUND AND PURPOSE Aging is associated with a reduction in cerebral perfusion. Impaired vasodilatation in large brain arteries could be implicated. This study sought age-related changes in vasodilator responses to norepinephrine in rat basilar artery and investigated which aspects of norepinephrine's action are responsible. To study the effect of aging per se, we used the rat, an animal with resistance to development of age-related pathologies. METHODS Vascular responses were studied in basilar arteries from young (3 to 4 months old) and old (20 to 22 months old) normotensive Sprague-Dawley rats with wire myography. Endothelial structure was assessed with confocal microscopy. RESULTS There was no age-related difference in blood pressure and in KCl or 5-hydroxytryptamine (5-HT) contractions. Relaxation to bradykinin or its absence predicted an intact or denuded endothelium, confirmed by confocal microscopy. Norepinephrine produced concentration-dependent relaxation that was significantly smaller in old rats, with or without endothelium. This response was significantly smaller in endothelium-denuded vessels, or after preincubation with NG-nitro-L-arginine methyl ester or propranolol, but not with rauwolscine. CONCLUSIONS In old and young rats the vasodilator action of norepinephrine in basilar artery is dependent on beta-adrenoceptors and nitric oxide. The impaired vasodilatation to norepinephrine found in the basilar artery from old rats might be caused by (1) a reduction in nitric oxide production and/or release or (2) beta-adrenoceptor alteration at the endothelium and/or the vascular smooth muscle. This impairment of vasodilator function can be ascribed to the aging process per se and not to other age-related alterations, such as hypertension.
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Affiliation(s)
- S M Arribas
- Institute of Biomedical and Life Sciences, University of Glasgow, UK.
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Sundaram K, Johnson SM, Felder RB. Altered expression of delayed excitation in medial NTS neurons of spontaneously hypertensive rats. Neurosci Lett 1997; 225:205-9. [PMID: 9147406 DOI: 10.1016/s0304-3940(97)00214-0] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
The spontaneously hypertensive (SH) rat has an exaggerated sympathetic discharge which may result from an enhanced neuronal excitability in the central nervous system. To test this hypothesis, we examined the electrophysiological properties of neurons in the medial region of the nucleus of the solitary tract (mNTS), a central nucleus involved in the processing of baroreceptor afferent information, in SH rats and normotensive Sprague-Dawley (SD) rats. An in vitro brainstem slice preparation was used to record intracellularly from 18 neurons in 4-5-month-old SH rats and 16 neurons in 4-5-month-old SD rats. Between the two groups there was no significant differences in resting membrane potential, input resistance, and spontaneous firing frequency, or in action potential amplitude, duration, and after-hyperpolarization (AHP). There were no significant differences in spike frequency adaptation and post-tetanic hyperpolarization (PTH). Delayed excitation (DE), a manifestation of A-current, occurred in 88% in SH and SD mNTS neurons, but the duration of DE was significantly (P < 0.05) shorter in SH mNTS neurons. We propose that attenuated expression of A-current may contribute to increased sympathetic drive in SH rats.
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Affiliation(s)
- K Sundaram
- Department of Internal Medicine, College of Medicine, University of Iowa, Iowa City 52242, USA
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23
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Buñag RD, Davidow LW. Aging impairs heart rate reflexes earlier in female than in male Sprague-Dawley rats. Neurobiol Aging 1996; 17:87-93. [PMID: 8786808 DOI: 10.1016/0197-4580(95)02031-4] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
We compared heart rate reflexes in conscious male or female Sprague-Dawley rats at ages of 4, 14, or 24 months to determine whether, with advancing age, baroreflex sensitivity diminishes uniformly in both sexes. Phenylephrine or sodium nitroprusside was infused intravenously to elevate or lower systemic arterial pressure and thereby elicit reflex changes in heart rate. Ensuing blood pressure responses to either drug were smaller at 24 months than at 4 or 14 months in males but did not differ between age groups in females. By contrast, reductions in reflex tachycardia or bradycardia were significant at 14 and 24 months in females but only at 24 months in males. Regression slopes from 4 to 14 months of age, though unaltered in males, fell significantly in females (from 2.35 +/- 0.2 to 1.28 +/- 0.2 for tachycardia, and from -2.17 +/- 0.1 to -1.46 +/- 0.1 for bradycardia). Thus, heart rate reflexes though eventually impaired in both sexes, were impaired earlier in females than in males.
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Affiliation(s)
- R D Buñag
- Department of Pharmacology, Toxicology and Therapeutics, University of Kansas Medical Center, Kansas City, 66160, USA
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Li M, Martin A, Wen C, Turner SW, Lewis LK, Whitworth JA. Long-term ouabain administration does not alter blood pressure in conscious Sprague-Dawley rats. Clin Exp Pharmacol Physiol 1995; 22:919-23. [PMID: 8846513 DOI: 10.1111/j.1440-1681.1995.tb02327.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
1. We tested the ability of ouabain to cause chronic hypertension by continuously infusing ouabain for 28 days (miniosmotic pump implantation; i.p.). The blood pressure and metabolic effects of sham (150 mmol/L NaCl; n = 12) or ouabain infusion (10 micrograms/kg per day; n = 14; 100 micrograms/kg per day; n = 14) were examined in conscious Sprague-Dawley rats. 2. Plasma ouabain concentrations measured after 28 days of ouabain infusion were as follows: sham, not detectable (n = 11); ouabain 10 micrograms/kg per day, 0.60 +/- 0.07 nmol/L (n = 14); and ouabain 100 micrograms/kg per day, 7.17 +/- 0.57 nmol/L (n = 14; P < 0.001). 3. Sham or ouabain infusion did not alter food intake, bodyweight, water intake or urine output in conscious rats. 4. Blood pressure was not altered by sham treatment. Ouabain at 10 micrograms/kg per day or 100 micrograms/kg per day did not produce consistent rises in blood pressure. Ouabain at 10 micrograms/kg per day increased blood pressure on treatment day 12 only (+6 mmHg; P < 0.05), while at 100 micrograms/kg per day blood pressure increased on treatment days 16 (+9 mmHg; P < 0.05) and day 18 (+8 mmHg; P < 0.05) only. There was no significant difference in blood pressure between sham and ouabain groups. 5. Renal blood flow was decreased in rats infused with ouabain at 10 micrograms/kg per day (2.0 +/- 0.3 mL/min per 100 g bodyweight; n = 5; P < 0.01) and 100 micrograms/kg per day (2.2 +/- 0.4 mL/min per 100 g bodyweight; n = 7; P < 0.05) compared with sham treatment (3.5 +/- 0.2 mL/min per 100 g bodyweight; n = 6). Renal vascular resistance was increased in rats treated with ouabain at 10 micrograms/kg per day (65.5 +/- 12.6 mmHg/mL per min per 100 g bodyweight; n = 5; P < 0.01) and 100 micrograms/kg per day (66.0 +/- 15.6 mmHg/mL per min per 100 g bodyweight; n = 7; P < 0.05) compared with sham treatment (32.6 +/- 2.5 mmHg/mL per min per 100 g bodyweight; n = 6). 6. High plasma concentrations of ouabain do not cause consistent increases in blood pressure in conscious Sprague-Dawley rats.
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Affiliation(s)
- M Li
- Department of Medicine, St. George Hospital, University of New South Wales, Australia
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Clark JT. Sexual function in altered physiological states: comparison of effects of hypertension, diabetes, hyperprolactinemia, and others to "normal" aging in male rats. Neurosci Biobehav Rev 1995; 19:279-302. [PMID: 7630583 DOI: 10.1016/0149-7634(94)00058-9] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
In this review, we examine the changes in sexual function that accompany deviations from "normal" physiological states. We propose that the changes one observes in many altered physiological states should not be viewed in isolation. We describe our paradigms for assessing sexual function, and proceed to evaluate how sexual function changes with hormonal deprivation and aging, in rat models for hypertension, in severe hyperprolactinemia, in streptozotocin-induced diabetes, after chronic alcohol intake, after chronic morphine administration, and after exposure to the heavy metal, cadmium. We will provide evidence for the involvement of adrenergic transmitters and two neuropeptides, neuropeptide Y and somatostatin, in the neuroendocrine regulation of sexual behavior. Finally, we compare and contrast the changes observed relative to the changes seen in "normal" aging in rats. The sequence of age-related changes in sexual function is distinct. The first change observed is a decrement in ex copula erectile reflexes. Next are decreases in ejaculatory threshold, followed shortly by increases in initiation and reinitiation of copulation after ejaculation. This is followed by a decrement in the number of males copulating to ejaculation. Finally, there is a failure to initiate the copulatory process. This sequelae is relatively common, being evident after castration, with hyperprolactinemia, and after exposure to cadmium. The data available for sexual function in hypertension is incomplete and modified by the etiology, but a suggestion for this sequelae is seen in SHR. In contrast, sexual dysfunction associated with chronic morphine administration appears to be due to an initial deficit in motivational aspects. Testosterone reverses sexual dysfunction associated with castration, but not with idiopathic sexual inactivity, nor with sexual dysfunction associated with aging, diabetes, or chronic morphine administration. Comparing sexual function in rat models for hypertension, diabetes and chronic ethanol leads to the conclusion that increases in blood pressure, like decreases in testosterone, cannot be the primary causal factor for sexual dysfunction. Age, hormonal history of the subject, and the age at castration influence changes in sexual function. Age-related sexual dysfunction appears to be contributed to by changes in adrenergic-neuropeptidergic, to include sympathetic, systems. Site-specific administration of NPY induces alterations in parameters of copulatory behavior which mimic those seen in aging and the retention of ejaculatory behavior with aging is associated with site-selective attenuation (or reversal) of age-associated changes in NPY content. Yohimbine enhances copulatory activity in castrated and aging rats, and attenuates or reverses the antisexual effects of clonidine, epinephrine and somatostatin.(ABSTRACT TRUNCATED AT 400 WORDS)
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Affiliation(s)
- J T Clark
- Department of Physiology, Meharry Medical College, Nashville, TN 37208, USA
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Mehta RS, Gunnett CA, Harris SR, Bunce OR, Hartle DK. High fish oil diet increases oxidative stress potential in mammary gland of spontaneously hypertensive rats. Clin Exp Pharmacol Physiol 1994; 21:881-9. [PMID: 7882579 DOI: 10.1111/j.1440-1681.1994.tb02459.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
1. The purpose of this study was to determine whether high omega-3 (19% menhaden oil, 1% corn oil) or high omega-6 (20% corn oil) fatty acid diets would decrease expression of hypertension in the female spontaneously hypertensive rat (SHR), promote tumourigenesis in the rat 7,12-dimethylbenz[a]anthracene (DMBA) model of mammary cancer or increase the susceptibility of the mammary gland to lipid peroxidation. A group of rats on a 5% corn oil diet served as the low fat control group. 2. We found that the high omega-3 and high omega-6 fatty acid diets did not significantly decrease mean arterial pressure. Marked differences occurred between the effects of omega-3 and omega-6 high fatty acid diets on baseline oxidation, auto-oxidation and iron-ascorbate catalyzed oxidation. The omega-3 diet showed 675% increase in basal oxidation, a 2624% increase in auto-oxidation and a 4244% increase in iron-ascorbate catalyzed oxidation compared to the omega-6 diet in mammary tissue homogenates. Although all rats were given 5 mg DMBA (i.g.), no mammary tumours were observed in any of the dietary groups. 3. We conclude that: (i) high polyunsaturated fatty acid diets do not decrease blood pressure in the female SHR; (ii) high fish oil diet markedly increases oxidative potential in the mammary gland; and (iii) the female SHR is resistant to DMBA-induced tumourigenesis.
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Affiliation(s)
- R S Mehta
- Department of Pharmacology and Toxicology, College of Pharmacy, University of Georgia, Athens 30605-2356
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Molina R, Sánchez M, Hidalgo A, García de Boto MJ. Influences of age and sex on endothelium-dependent vascular responses and arterial blood pressure in the rat. GENERAL PHARMACOLOGY 1994; 25:753-9. [PMID: 7958738 DOI: 10.1016/0306-3623(94)90256-9] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
1. Vascular reactivity related to age and sex on two endothelium-dependent effects in isolated rat aorta (acetylcholine-induced relaxation and modulation of noradrenaline response) and blood pressure decreases by acetylcholine administration were studied. Group of male Wistar rats aged 2, 4, 8, 16 and 24 months plus female rats of 4 months were used. 2. Blood pressure was measured by using a standard tail-cuff technique. Acetylcholine in vivo administration (0.002 mg/kg i.v.) significantly reduced diastolic pressures in the 2 month old males and 4 month old females, but not in other age groups. 3. Isolated helical strips of rat aorta were used to determine the endothelium-dependent reactivity. The maximal relaxation from different groups of male rats induced by acetylcholine was: 100% in those of 2 months; 53.2 +/- 6.0% in those of 4 months; 61.8 +/- 6.1% in those of 8 months; 57.6 +/- 5.0% in those of 16 months and 31.0 +/- 4.9% in those of 24 months. Concentration-response curves to noradrenaline were significantly greater only when endothelial cells were removed from aorta strips of 2 month old rats. In aorta strips with endothelium the maximal contraction to noradrenaline was significantly greater in 2 month old rats when compared with the other groups and smaller in aorta strips from 24 month old rats. 4. These results suggest that the endothelium-dependent effects studied and the noradrenaline-induced contraction decreased according to the age of the rats.
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Affiliation(s)
- R Molina
- Laboratorio de Farmacología, Departamento Medicina Facultad Medicina, Oviedo, Spain
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Atkinson J, Tatchum-Talom R, Capdeville-Atkinson C. Reduction of endothelial function with age in the mesenteric arterial bed of the normotensive rat. Br J Pharmacol 1994; 111:1184-8. [PMID: 8032604 PMCID: PMC1910149 DOI: 10.1111/j.1476-5381.1994.tb14870.x] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
1. Age-related changes in endothelial vasodilator function were studied in an in vitro preparation of the mesenteric arterial bed removed from male, normotensive, Wistar rats. 2. Animals were killed at 2, 12 or 22 months of age, the superior mesenteric artery was cannulated and the gut removed. The mesenteric arterial bed was perfused at a constant flow rate of 4 ml min-1 and perfusion pressure was taken as an index of arteriolar tone. 3. The muscarinic agonist, carbachol, antagonized noradrenaline-induced vasoconstriction in the presence, but not in the absence, of endothelium. This cholinoceptor agonist-induced release of endothelial-derived relaxing factor (EDRF) was impaired in 22 month old rats. 4. Noradrenaline-induced vasoconstriction increased following removal of endothelium suggesting that agonist-induced release of EDRF attenuates vasoconstrictor responses to noradrenaline measured in the presence of endothelium. 5. Removal of endothelium had less effect on noradrenaline-induced vasoconstriction in old rats suggesting once again that agonist-induced release of EDRF is impaired in old rats. 6. The noradrenaline dose-response curve established in the presence of endothelium was shifted to the left in 22 month old rats. 7. In conclusion, aging in the rat appears to lead to a reduction in endothelial vasodilator function in a resistance vessel.
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Affiliation(s)
- J Atkinson
- Laboratoire de Pharmacologie Cardio-vasculaire, Faculté de Pharmacie de l'Université de Nancy I, France
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Clark JT. Aging-induced decrements in neuropeptide Y: the retention of ejaculatory behavior is associated with site-selective differences. Neurobiol Aging 1994; 15:191-6. [PMID: 7838290 DOI: 10.1016/0197-4580(94)90111-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Neuropeptide Y (NPY) has been implicated in the control of reproductive and cardiovascular function. We observed an age-related decrease in the number of males copulating to ejaculation and a moderate systolic hypertension in middle-aged (16- to 17-month-old) rats. NPY content was examined in microdissected brain nuclei in 5 groups of rats: 2 groups of young rats, 1 heterosexually naive and the other ejaculating in 3 successive mating test; 3 groups of middle-aged rats, 1 heterosexually naive, 1 group that had extensive sexual experience but failed to ejaculate in tests at 16.5 months of age, and the third continuing to ejaculate at 16.5 months of age. NPY levels were found to vary depending on the brain area, the age of the animals, and the maintenance of ejaculatory behavior. In sexually naive middle-aged males, NPY levels were uniformly lower than in younger males. There were no differences in NPY levels of young animals, regardless of sexual experience. In the medial preoptic area, the group that retained ejaculatory behavior through 16.5 months of age, had higher levels of NPY than those observed in young sexually experienced rats. In sexually experienced rats that were no longer ejaculating at 16.5 months of age levels were lower than all other groups except the sexually naive middle-aged group. In the hypothalamic arcuate nucleus, levels were equivalent in the young groups and in the middle-aged rats that retained ejaculatory behavior, being greater than in the middle-aged rats that were no longer ejaculating or were sexually naive.(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- J T Clark
- Department of Physiology, Meharry Medical College, Nashville, TN 37208
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