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Al-Nuaimi DA, Rütsche D, Abukar A, Hiebert P, Zanetti D, Cesarovic N, Falk V, Werner S, Mazza E, Giampietro C. Hydrostatic pressure drives sprouting angiogenesis via adherens junction remodelling and YAP signalling. Commun Biol 2024; 7:940. [PMID: 39097636 PMCID: PMC11297954 DOI: 10.1038/s42003-024-06604-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2023] [Accepted: 07/17/2024] [Indexed: 08/05/2024] Open
Abstract
Endothelial cell physiology is governed by its unique microenvironment at the interface between blood and tissue. A major contributor to the endothelial biophysical environment is blood hydrostatic pressure, which in mechanical terms applies isotropic compressive stress on the cells. While other mechanical factors, such as shear stress and circumferential stretch, have been extensively studied, little is known about the role of hydrostatic pressure in the regulation of endothelial cell behavior. Here we show that hydrostatic pressure triggers partial and transient endothelial-to-mesenchymal transition in endothelial monolayers of different vascular beds. Values mimicking microvascular pressure environments promote proliferative and migratory behavior and impair barrier properties that are characteristic of a mesenchymal transition, resulting in increased sprouting angiogenesis in 3D organotypic model systems ex vivo and in vitro. Mechanistically, this response is linked to differential cadherin expression at the adherens junctions, and to an increased YAP expression, nuclear localization, and transcriptional activity. Inhibition of YAP transcriptional activity prevents pressure-induced sprouting angiogenesis. Together, this work establishes hydrostatic pressure as a key modulator of endothelial homeostasis and as a crucial component of the endothelial mechanical niche.
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Affiliation(s)
| | - Dominic Rütsche
- Empa, Swiss Federal Laboratories for Materials Science and Technology, Experimental Continuum Mechanics, Dübendorf, 8600, Switzerland
| | - Asra Abukar
- ETH Zürich, DMAVT, Experimental Continuum Mechanics, Zürich, 8092, Switzerland
| | - Paul Hiebert
- Department of Biology, ETH Zürich, Institute of Molecular Health Sciences, 8093, Zürich, Switzerland
- Centre for Biomedicine, Hull York Medical School, The University of Hull, Hull, HU6 7RX, UK
| | - Dominik Zanetti
- Department of Biology, ETH Zürich, Institute of Molecular Health Sciences, 8093, Zürich, Switzerland
| | - Nikola Cesarovic
- Department of Cardiothoracic and Vascular Surgery, German Heart Center Berlin, 13353, Berlin, Germany
- Department of Health Sciences and Technology, ETH Zürich, 8093, Zürich, Switzerland
| | - Volkmar Falk
- Department of Cardiothoracic and Vascular Surgery, German Heart Center Berlin, 13353, Berlin, Germany
- Department of Health Sciences and Technology, ETH Zürich, 8093, Zürich, Switzerland
| | - Sabine Werner
- Department of Biology, ETH Zürich, Institute of Molecular Health Sciences, 8093, Zürich, Switzerland
| | - Edoardo Mazza
- ETH Zürich, DMAVT, Experimental Continuum Mechanics, Zürich, 8092, Switzerland.
- Empa, Swiss Federal Laboratories for Materials Science and Technology, Experimental Continuum Mechanics, Dübendorf, 8600, Switzerland.
| | - Costanza Giampietro
- ETH Zürich, DMAVT, Experimental Continuum Mechanics, Zürich, 8092, Switzerland.
- Empa, Swiss Federal Laboratories for Materials Science and Technology, Experimental Continuum Mechanics, Dübendorf, 8600, Switzerland.
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Haq KT, McLean K, Salameh S, Swift LM, Posnack NG. Electroanatomical adaptations in the guinea pig heart from neonatal to adulthood. Europace 2024; 26:euae158. [PMID: 38864516 PMCID: PMC11218563 DOI: 10.1093/europace/euae158] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2024] [Accepted: 06/06/2024] [Indexed: 06/13/2024] Open
Abstract
AIMS Electroanatomical adaptations during the neonatal to adult phase have not been comprehensively studied in preclinical animal models. To explore the impact of age as a biological variable on cardiac electrophysiology, we employed neonatal and adult guinea pigs, which are a recognized animal model for developmental research. METHODS AND RESULTS Electrocardiogram recordings were collected in vivo from anaesthetized animals. A Langendorff-perfusion system was employed for the optical assessment of action potentials and calcium transients. Optical data sets were analysed using Kairosight 3.0 software. The allometric relationship between heart weight and body weight diminishes with age, it is strongest at the neonatal stage (R2 = 0.84) and abolished in older adults (R2 = 1E-06). Neonatal hearts exhibit circular activation, while adults show prototypical elliptical shapes. Neonatal conduction velocity (40.6 ± 4.0 cm/s) is slower than adults (younger: 61.6 ± 9.3 cm/s; older: 53.6 ± 9.2 cm/s). Neonatal hearts have a longer action potential duration (APD) and exhibit regional heterogeneity (left apex; APD30: 68.6 ± 5.6 ms, left basal; APD30: 62.8 ± 3.6), which was absent in adults. With dynamic pacing, neonatal hearts exhibit a flatter APD restitution slope (APD70: 0.29 ± 0.04) compared with older adults (0.49 ± 0.04). Similar restitution characteristics are observed with extrasystolic pacing, with a flatter slope in neonates (APD70: 0.54 ± 0.1) compared with adults (younger: 0.85 ± 0.4; older: 0.95 ± 0.7). Neonatal hearts display unidirectional excitation-contraction coupling, while adults exhibit bidirectionality. CONCLUSION Postnatal development is characterized by transient changes in electroanatomical properties. Age-specific patterns can influence cardiac physiology, pathology, and therapies for cardiovascular diseases. Understanding heart development is crucial to evaluating therapeutic eligibility, safety, and efficacy.
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Affiliation(s)
- Kazi T Haq
- Sheikh Zayed Institute for Pediatric Surgical Innovation, Children’s National Hospital, 111 Michigan Avenue, NW, Washington, DC 20010, USA
- Children’s National Heart Institute, Children’s National Hospital, Washington, DC, USA
| | - Kate McLean
- Sheikh Zayed Institute for Pediatric Surgical Innovation, Children’s National Hospital, 111 Michigan Avenue, NW, Washington, DC 20010, USA
| | - Shatha Salameh
- Sheikh Zayed Institute for Pediatric Surgical Innovation, Children’s National Hospital, 111 Michigan Avenue, NW, Washington, DC 20010, USA
- Children’s National Heart Institute, Children’s National Hospital, Washington, DC, USA
- Department of Pharmacology and Physiology, The George Washington University School of Medicine and Health Sciences, Washington, DC, USA
| | - Luther M Swift
- Sheikh Zayed Institute for Pediatric Surgical Innovation, Children’s National Hospital, 111 Michigan Avenue, NW, Washington, DC 20010, USA
- Children’s National Heart Institute, Children’s National Hospital, Washington, DC, USA
| | - Nikki Gillum Posnack
- Sheikh Zayed Institute for Pediatric Surgical Innovation, Children’s National Hospital, 111 Michigan Avenue, NW, Washington, DC 20010, USA
- Children’s National Heart Institute, Children’s National Hospital, Washington, DC, USA
- Department of Pharmacology and Physiology, The George Washington University School of Medicine and Health Sciences, Washington, DC, USA
- Department of Pediatrics, The George Washington University School of Medicine and Health Sciences, Washington, DC, USA
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DiNuzzo M, Dienel GA, Behar KL, Petroff OA, Benveniste H, Hyder F, Giove F, Michaeli S, Mangia S, Herculano-Houzel S, Rothman DL. Neurovascular coupling is optimized to compensate for the increase in proton production from nonoxidative glycolysis and glycogenolysis during brain activation and maintain homeostasis of pH, pCO 2, and pO 2. J Neurochem 2024; 168:632-662. [PMID: 37150946 PMCID: PMC10628336 DOI: 10.1111/jnc.15839] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2022] [Revised: 04/22/2023] [Accepted: 05/02/2023] [Indexed: 05/09/2023]
Abstract
During transient brain activation cerebral blood flow (CBF) increases substantially more than cerebral metabolic rate of oxygen consumption (CMRO2) resulting in blood hyperoxygenation, the basis of BOLD-fMRI contrast. Explanations for the high CBF versus CMRO2 slope, termed neurovascular coupling (NVC) constant, focused on maintenance of tissue oxygenation to support mitochondrial ATP production. However, paradoxically the brain has a 3-fold lower oxygen extraction fraction (OEF) than other organs with high energy requirements, like heart and muscle during exercise. Here, we hypothesize that the NVC constant and the capillary oxygen mass transfer coefficient (which in combination determine OEF) are co-regulated during activation to maintain simultaneous homeostasis of pH and partial pressure of CO2 and O2 (pCO2 and pO2). To test our hypothesis, we developed an arteriovenous flux balance model for calculating blood and brain pH, pCO2, and pO2 as a function of baseline OEF (OEF0), CBF, CMRO2, and proton production by nonoxidative metabolism coupled to ATP hydrolysis. Our model was validated against published brain arteriovenous difference studies and then used to calculate pH, pCO2, and pO2 in activated human cortex from published calibrated fMRI and PET measurements. In agreement with our hypothesis, calculated pH, pCO2, and pO2 remained close to constant independently of CMRO2 in correspondence to experimental measurements of NVC and OEF0. We also found that the optimum values of the NVC constant and OEF0 that ensure simultaneous homeostasis of pH, pCO2, and pO2 were remarkably similar to their experimental values. Thus, the high NVC constant is overall determined by proton removal by CBF due to increases in nonoxidative glycolysis and glycogenolysis. These findings resolve the paradox of the brain's high CBF yet low OEF during activation, and may contribute to explaining the vulnerability of brain function to reductions in blood flow and capillary density with aging and neurovascular disease.
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Affiliation(s)
| | - Gerald A Dienel
- Department of Neurology, University of Arkansas for Medical Sciences, Little Rock, AR, 72205 USA
- Department of Cell Biology and Physiology, University of New Mexico School of Medicine, Albuquerque, NM, 87131 USA
| | - Kevin L Behar
- Department of Psychiatry, Yale University School of Medicine, New Haven, CT, 06511 USA
| | - Ognen A Petroff
- Department of Psychiatry, Yale University School of Medicine, New Haven, CT, 06511 USA
| | - Helene Benveniste
- Department of Anesthesiology, Yale University, New Haven, CT, 06520 USA
- Department of Biomedical Engineering, Yale University, New Haven, CT, 06520 USA
| | - Fahmeed Hyder
- Department of Biomedical Engineering, Yale University, New Haven, CT, 06520 USA
- Department of Radiology, Magnetic Resonance Research Center (MRRC), Yale University, New Haven, CT, 06520 USA
| | - Federico Giove
- Centro Ricerche Enrico Fermi, Rome, RM, 00184 Italy
- Fondazione Santa Lucia IRCCS, Rome, RM, 00179 Italy
| | - Shalom Michaeli
- Department of Radiology, Center for Magnetic Resonance Research (CMRR), University of Minnesota, Minneapolis, MN, 55455 USA
| | - Silvia Mangia
- Department of Radiology, Center for Magnetic Resonance Research (CMRR), University of Minnesota, Minneapolis, MN, 55455 USA
| | - Suzana Herculano-Houzel
- Department of Psychology, Vanderbilt University, Nashville, TN
- Department of Biological Sciences, Vanderbilt University, Nashville, TN
- Vanderbilt Brain Institute, Vanderbilt University, Nashville, TN
| | - Douglas L Rothman
- Department of Biomedical Engineering, Yale University, New Haven, CT, 06520 USA
- Department of Radiology, Magnetic Resonance Research Center (MRRC), Yale University, New Haven, CT, 06520 USA
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Rego BV, Murtada SI, Li G, Tellides G, Humphrey JD. Multiscale insights into postnatal aortic development. Biomech Model Mechanobiol 2024; 23:687-701. [PMID: 38151614 DOI: 10.1007/s10237-023-01800-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2023] [Accepted: 11/27/2023] [Indexed: 12/29/2023]
Abstract
Despite its vital importance for establishing proper cardiovascular function, the process through which the vasculature develops and matures postnatally remains poorly understood. From a clinical perspective, an ability to mechanistically model the developmental time course in arteries and veins, as well as to predict how various pathologies and therapeutic interventions alter the affected vessels, promises to improve treatment strategies and long-term clinical outcomes, particularly in pediatric patients suffering from congenital heart defects. In the present study, we conducted a multiscale investigation into the postnatal development of the murine thoracic aorta, examining key allometric relations as well as relationships between in vivo mechanical stresses, collagen and elastin expression, and the gradual accumulation of load-bearing constituents within the aortic wall. Our findings suggest that the production of fibrillar collagens in the developing aorta associates strongly with the ratio of circumferential stresses between systole and diastole, hence emphasizing the importance of a pulsatile mechanobiological stimulus. Moreover, rates of collagen turnover and elastic fiber compaction can be inferred directly by synthesizing transcriptional data and quantitative histological measurements of evolving collagen and elastin content. Consistent with previous studies, we also observed that wall shear stresses acting on the aorta are similar at birth and in maturity, supporting the hypothesis that at least some stress targets are established early in development and maintained thereafter, thus providing a possible homeostatic basis to guide future experiments and inform future predictive modeling.
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Affiliation(s)
- Bruno V Rego
- Department of Biomedical Engineering, Yale University, New Haven, CT, USA
- Department of Biological & Agricultural Engineering, Louisiana State University, Baton Rouge, LA, USA
| | - Sae-Il Murtada
- Department of Biomedical Engineering, Yale University, New Haven, CT, USA
| | - Guangxin Li
- Department of Surgery, Yale School of Medicine, New Haven, CT, USA
| | - George Tellides
- Department of Surgery, Yale School of Medicine, New Haven, CT, USA
- Vascular Biology and Therapeutics Program, Yale School of Medicine, New Haven, CT, USA
| | - Jay D Humphrey
- Department of Biomedical Engineering, Yale University, New Haven, CT, USA.
- Vascular Biology and Therapeutics Program, Yale School of Medicine, New Haven, CT, USA.
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Haq KT, McLean K, Salameh S, Swift L, Posnack NG. Electroanatomical Adaptations in the Guinea Pig Heart from Neonatal to Adulthood. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.01.26.577234. [PMID: 38352347 PMCID: PMC10862765 DOI: 10.1101/2024.01.26.577234] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2024]
Abstract
Background Electroanatomical adaptations during the neonatal to adult phase have not been comprehensively studied in preclinical animal models. To explore the impact of age as a biological variable on cardiac electrophysiology, we employed neonatal and adult guinea pigs, which are a recognized animal model for developmental research. Methods Healthy guinea pigs were categorized into three age groups (neonates, n=10; younger adults, n=13; and older adults, n=26). Electrocardiogram (ECG) recordings were collected in vivo from anesthetized animals (2-3% isoflurane). A Langendorff-perfusion system was employed for optical assessment of epicardial action potentials and calcium transients, using intact excised heart preparations. Optical data sets were analyzed and metric maps were constructed using Kairosight 3.0. Results The allometric relationship between heart weight and body weight diminishes with age, as it is strongest at the neonatal stage (R 2 = 0.84) and completely abolished in older adults (R 2 = 1E-06). Neonatal hearts exhibit circular activation waveforms, while adults show prototypical elliptical shapes. Neonatal conduction velocity (40.6±4.0 cm/s) is slower than adults (younger adults: 61.6±9.3 cm/s; older adults: 53.6±9.2 cm/s). Neonatal hearts have a longer action potential duration (APD) and exhibit regional heterogeneity (left apex; APD30: 68.6±5.6 ms, left basal; APD30: 62.8±3.6), which was absent in adult epicardium. With dynamic pacing, neonatal hearts exhibit a flatter APD restitution slope (APD70: 0.29±0.04) compared to older adults (0.49±0.04). Similar restitution characteristics are observed with extrasystolic pacing, with a flatter slope in neonatal hearts (APD70: 0.54±0.1) compared to adults (Younger adults: 0.85±0.4; Older adults: 0.95±0.7). Finally, neonatal hearts display unidirectional excitation-contraction coupling, while adults exhibit bidirectionality. Conclusion The transition from neonatal to adulthood in guinea pig hearts is characterized by transient changes in electroanatomic properties. Age-specific patterns can influence cardiac physiology, pathology, and therapies for cardiovascular diseases. Understanding postnatal heart development is crucial to evaluating therapeutic eligibility, safety, and efficacy. What is Known Age-specific cardiac electroanatomical characteristics have been documented in humans and some preclinical animal models. These age-specific patterns can influence cardiac physiology, pathology, and therapies for cardiovascular diseases. What the Study Adds Cardiac electroanatomical characteristics are age-specific in guinea pigs, a well-known preclinical model for developmental studies. Age-dependent adaptations in cardiac electrophysiology are readily observed in the electrocardiogram recordings and via optical mapping of epicardial action potentials and calcium transients. Our findings reveal unique activation and repolarization characteristics between neonatal and adult animals.
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Kraskura K, Hardison EA, Eliason EJ. Body size and temperature affect metabolic and cardiac thermal tolerance in fish. Sci Rep 2023; 13:17900. [PMID: 37857749 PMCID: PMC10587238 DOI: 10.1038/s41598-023-44574-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2023] [Accepted: 10/10/2023] [Indexed: 10/21/2023] Open
Abstract
Environmental warming is associated with reductions in ectotherm body sizes, suggesting that larger individuals may be more vulnerable to climate change. The mechanisms driving size-specific vulnerability to temperature are unknown but are required to finetune predictions of fisheries productivity and size-structure community responses to climate change. We explored the potential metabolic and cardiac mechanisms underlying these body size vulnerability trends in a eurythermal fish, barred surfperch. We acutely exposed surfperch across a large size range (5-700 g) to four ecologically relevant temperatures (16 °C, 12 °C, 20 °C, and 22 °C) and subsequently, measured their metabolic capacity (absolute and factorial aerobic scopes, maximum and resting metabolic rates; AAS, FAS, MMR, RMR). Additionally, we estimated the fish's cardiac thermal tolerance by measuring their maximum heart rates (fHmax) across acutely increasing temperatures. Barred surfperch had parallel hypoallometric scaling of MMR and RMR (exponent 0.81) and a weaker hypoallometric scaling of fHmax (exponent - 0.05) across all test temperatures. In contrast to our predictions, the fish's aerobic capacity was maintained across sizes and acute temperatures, and larger fish had greater cardiac thermal tolerance than smaller fish. These results demonstrate that thermal performance may be limited by different physiological constraints depending on the size of the animal and species of interest.
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Affiliation(s)
- Krista Kraskura
- Department of Ecology, Evolution and Marine Biology, University of California, Santa Barbara, CA, 93106, USA.
| | - Emily A Hardison
- Department of Ecology, Evolution and Marine Biology, University of California, Santa Barbara, CA, 93106, USA
| | - Erika J Eliason
- Department of Ecology, Evolution and Marine Biology, University of California, Santa Barbara, CA, 93106, USA
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Turcanu S, Gusetu G, Ciobanu DM, Istratoaie S, Rosu R, Alexandru MI, Muresan L, Lazea C, Pop D, Zdrenghea D, Cismaru G, Barsu C, Negru AG, Cismaru A, Cainap SS. Body size influences heart rate in children aged 6 to 18 years old. Medicine (Baltimore) 2023; 102:e32602. [PMID: 36701713 PMCID: PMC9857381 DOI: 10.1097/md.0000000000032602] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
Previous research established age-related normal limits for children's heart rates (HRs). However, children of the same age can have significantly different HRs, depending on whether they are overweight or underweight, tall or short. Studies on children HR have failed to find a clear correlation between HR and body size. The goal of our study was to create Z scores for HR based on weight (W), height (H), body mass index (BMI), and body surface area (BSA) and compare them to normal age-related HR limits. Electrocardiograms were recorded from a total of 22,460 healthy children ranging in age from 6 to 18 years old using BTL machines. A comparison was made between different age groups, in function of W, H, BMI, and BSA, based on the HR that was automatically detected by using the digitally stored electrocardiogram. Z scores were computed for each of the categories that were mentioned. Incremental Z score values between -2.5 and 2.5 were calculated to establish upper and lower limits of HR. The BSA's estimation of HR is the most accurate of the available methods and can be utilized with accuracy in clinical practice. Z scores for HR in children differ in function of the age, W, H, BMI and BSA. The best estimation is based on BSA. The novelty of our study is that we developed Z scores for HR in relation to body size, age and sex, producing a standardized, consistent, and reproducible result without requiring practitioners to learn and remember cutoff values for a wide range of variables across age groups and sexes. Z scores minimize observer and institutional bias, hence generating uniform and reproducible standards.
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Affiliation(s)
- Simona Turcanu
- 5th Department of Internal Medicine, Cardiology Rehabilitation, “Iuliu Hatieganu” University of Medicine and Pharmacy, Cluj-Napoca, Romania
| | - Gabriel Gusetu
- 5th Department of Internal Medicine, Cardiology Rehabilitation, “Iuliu Hatieganu” University of Medicine and Pharmacy, Cluj-Napoca, Romania
| | - Dana Mihaela Ciobanu
- Department of Diabetes and Nutrition Diseases, Iuliu Hatieganu University of Medicine and Pharmacy, Cluj-Napoca, Romania
| | - Sabina Istratoaie
- Department of Pharmacology, Toxicology and Clinical Pharmacology, Iuliu Hatieganu University of Medicine and Pharmacy, Cluj-Napoca, Romania
| | - Radu Rosu
- 5th Department of Internal Medicine, Cardiology Rehabilitation, “Iuliu Hatieganu” University of Medicine and Pharmacy, Cluj-Napoca, Romania
| | - Minciuna Ioan Alexandru
- 5th Department of Internal Medicine, Cardiology Rehabilitation, “Iuliu Hatieganu” University of Medicine and Pharmacy, Cluj-Napoca, Romania
| | - Lucian Muresan
- Cardiology Department, “Emile Muller” Hospital, Mulhouse, France
| | - Cecilia Lazea
- Department of Pediatrics I, Emergency Clinic Hospital for Children, “Iuliu Hatieganu” University of Medicine and Pharmacy, Cluj-Napoca, Romania
| | - Dana Pop
- 5th Department of Internal Medicine, Cardiology Rehabilitation, “Iuliu Hatieganu” University of Medicine and Pharmacy, Cluj-Napoca, Romania
| | - Dumitru Zdrenghea
- 5th Department of Internal Medicine, Cardiology Rehabilitation, “Iuliu Hatieganu” University of Medicine and Pharmacy, Cluj-Napoca, Romania
| | - Gabriel Cismaru
- 5th Department of Internal Medicine, Cardiology Rehabilitation, “Iuliu Hatieganu” University of Medicine and Pharmacy, Cluj-Napoca, Romania
- * Correspondence: Gabriel Cismaru, 5th Department of Internal Medicine, Cardiology Rehabilitation, “Iuliu Hatieganu” University of Medicine and Pharmacy, Cluj-Napoca, Romania (e-mail: )
| | - Cristian Barsu
- Department of Abilities - Humanistic Sciences, “Iuliu Hatieganu” University of Medicine and Pharmacy, Cluj-Napoca, Romania
| | - Alina Gabriela Negru
- Department of Cardiology, “Victor Babeș” University of Medicine and Pharmacy of Timisoara, Timisoara, Romania
| | - Andrei Cismaru
- Research Center for Functional Genomics, Biomedicine and Translational Medicine, The “Iuliu Hatieganu” University of Medicine and Pharmacy, Cluj-Napoca, Romania
| | - Simona Sorana Cainap
- Department of Pediatrics II, Emergency Clinic Hospital for Children, “Iuliu Hatieganu” University of Medicine and Pharmacy, Cluj-Napoca, Romania
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Palgen JL, Perrillat-Mercerot A, Ceres N, Peyronnet E, Coudron M, Tixier E, Illigens BMW, Bosley J, L’Hostis A, Monteiro C. Integration of Heterogeneous Biological Data in Multiscale Mechanistic Model Calibration: Application to Lung Adenocarcinoma. Acta Biotheor 2022; 70:19. [PMID: 35796890 PMCID: PMC9261258 DOI: 10.1007/s10441-022-09445-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2022] [Accepted: 06/15/2022] [Indexed: 11/26/2022]
Abstract
Mechanistic models are built using knowledge as the primary information source, with well-established biological and physical laws determining the causal relationships within the model. Once the causal structure of the model is determined, parameters must be defined in order to accurately reproduce relevant data. Determining parameters and their values is particularly challenging in the case of models of pathophysiology, for which data for calibration is sparse. Multiple data sources might be required, and data may not be in a uniform or desirable format. We describe a calibration strategy to address the challenges of scarcity and heterogeneity of calibration data. Our strategy focuses on parameters whose initial values cannot be easily derived from the literature, and our goal is to determine the values of these parameters via calibration with constraints set by relevant data. When combined with a covariance matrix adaptation evolution strategy (CMA-ES), this step-by-step approach can be applied to a wide range of biological models. We describe a stepwise, integrative and iterative approach to multiscale mechanistic model calibration, and provide an example of calibrating a pathophysiological lung adenocarcinoma model. Using the approach described here we illustrate the successful calibration of a complex knowledge-based mechanistic model using only the limited heterogeneous datasets publicly available in the literature.
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Affiliation(s)
| | | | - Nicoletta Ceres
- Novadiscovery, Pl. Giovanni da Verrazzano, Lyon, 69009 Rhône France
| | | | - Matthieu Coudron
- Novadiscovery, Pl. Giovanni da Verrazzano, Lyon, 69009 Rhône France
| | - Eliott Tixier
- Novadiscovery, Pl. Giovanni da Verrazzano, Lyon, 69009 Rhône France
| | - Ben M. W. Illigens
- Novadiscovery, Pl. Giovanni da Verrazzano, Lyon, 69009 Rhône France
- Dresden International University, Freiberger Str. 37, Dresden, 01067 Germany
| | - Jim Bosley
- Novadiscovery, Pl. Giovanni da Verrazzano, Lyon, 69009 Rhône France
| | - Adèle L’Hostis
- Novadiscovery, Pl. Giovanni da Verrazzano, Lyon, 69009 Rhône France
| | - Claudio Monteiro
- Novadiscovery, Pl. Giovanni da Verrazzano, Lyon, 69009 Rhône France
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A high-throughput study of visceral organs in CT-scanned pigs. Sci Rep 2022; 12:9154. [PMID: 35650423 PMCID: PMC9160241 DOI: 10.1038/s41598-022-13253-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2021] [Accepted: 05/23/2022] [Indexed: 11/08/2022] Open
Abstract
It has been debated whether intensive selection for growth and carcass yield in pig breeding programmes can affect the size of internal organs, and thereby reduce the animal’s ability to handle stress and increase the risk of sudden deaths. To explore the respiratory and circulatory system in pigs, a deep learning based computational pipeline was built to extract the size of lungs and hearts from CT-scan images. This pipeline was applied on CT images from 11,000 boar selection candidates acquired during the last decade. Further, heart and lung volumes were analysed genetically and correlated with production traits. Both heart and lung volumes were heritable, with h2 estimated to 0.35 and 0.34, respectively, in Landrace, and 0.28 and 0.4 in Duroc. Both volumes were positively correlated with lean meat percentage, and lung volume was negatively genetically correlated with growth (rg = − 0.48 ± 0.07 for Landrace and rg = − 0.44 ± 0.07 for Duroc). The main findings suggest that the current pig breeding programs could, as an indirect response to selection, affect the size of hearts- and lungs. The presented methods can be used to monitor the development of internal organs in the future.
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10
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Le TTY, Kiwitt G, Nahar N, Nachev M, Grabner D, Sures B. What contributes to the metal-specific partitioning in the chub-acanthocephalan system? AQUATIC TOXICOLOGY (AMSTERDAM, NETHERLANDS) 2022; 247:106178. [PMID: 35489172 DOI: 10.1016/j.aquatox.2022.106178] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/09/2022] [Revised: 03/29/2022] [Accepted: 04/21/2022] [Indexed: 06/14/2023]
Abstract
Physiologically based pharmacokinetic (PBPK) models have been applied to simulate the absorption, distribution, metabolism, and elimination of various toxicants in fish. This approach allows for considering metal accumulation in intestinal parasites. Unlike "semi" physiologically-based models developed for metals, metal accumulation in fish was characterised based on metal-specific parameters (the fraction in blood plasma and the tissue-blood partition coefficient) and physiological characteristics of the fish (the blood flow and the tissue weight) in our PBPK model. In the model, intestinal parasites were considered a sink of metals from the host intestine. The model was calibrated with data for the system of the chub Squalius cephalus and the acanthocephalan Pomphorhynchus tereticolliis. Metal concentrations in this fish-parasite system were monitored in Ag and Co treatments in duplicate during a 48-day exposure phase (Ag and Co were added to tap water at concentrations of 1 and 2 µg/L, respectively) and a 51-day depuration phase. Their concentrations in the gills increased during the exposure phase and decreased in the depuration phase. A similar pattern was observed for Ag concentrations in other chub organs, while a relatively stable pattern for Co indicates regulations in the accumulation of essential metals by chubs. The metals were taken up by the acanthocephalans at similar rate constants. These results indicate that metal availability to parasites, which is determined by the internal distribution and fate, is critical to metal accumulation in the acanthocephalans. The high concentration of Ag in the liver as well as the high rate of Ag excretion from the liver to the intestine might contribute to higher concentrations of metals in the bile complexes in the intestine, which are available to the parasites, but not to the reabsorption by the host intestine. The opposite pattern might explain the lower availability of Co to the acanthocephalans.
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Affiliation(s)
- T T Yen Le
- Department of Aquatic Ecology and Centre for Water and Environmental Research (ZWU), Faculty of Biology, University of Duisburg-Essen, D-45141 Essen, Germany
| | - Gina Kiwitt
- Department of Aquatic Ecology and Centre for Water and Environmental Research (ZWU), Faculty of Biology, University of Duisburg-Essen, D-45141 Essen, Germany
| | - Nazmun Nahar
- Department of Aquatic Ecology and Centre for Water and Environmental Research (ZWU), Faculty of Biology, University of Duisburg-Essen, D-45141 Essen, Germany
| | - Milen Nachev
- Department of Aquatic Ecology and Centre for Water and Environmental Research (ZWU), Faculty of Biology, University of Duisburg-Essen, D-45141 Essen, Germany
| | - Daniel Grabner
- Department of Aquatic Ecology and Centre for Water and Environmental Research (ZWU), Faculty of Biology, University of Duisburg-Essen, D-45141 Essen, Germany
| | - Bernd Sures
- Department of Aquatic Ecology and Centre for Water and Environmental Research (ZWU), Faculty of Biology, University of Duisburg-Essen, D-45141 Essen, Germany
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11
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Árpádffy-Lovas T, Mohammed ASA, Naveed M, Koncz I, Baláti B, Bitay M, Jost N, Nagy N, Baczkó I, Virág L, Varró A. Species dependent differences in the inhibition of various potassium currents and in their effects on repolarization in cardiac ventricular muscle. Can J Physiol Pharmacol 2022; 100:880-889. [PMID: 35442802 DOI: 10.1139/cjpp-2022-0028] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Even though rodents are accessible model animals, their electrophysiological properties are deeply different from that of human, making the translation of rat studies to human rather difficult. We compared the mechanisms of ventricular repolarization in various animal models to those of human by measuring cardiac ventricular action potentials from ventricular papillary muscle preparations using conventional microelectrodes, and applying selective inhibitors of various potassium transmembrane ion currents. Inhibition of the IK1 current (10 µM barium chloride) significantly prolonged rat ventricular repolarization, but only slightly prolonged it in dog, and did not affect it in human. On the contrary, IKr inhibition (50 nM dofetilide) significantly prolonged repolarization in human, rabbit, and dog, but not in rat. Inhibition of the IKur current (1 µM XEN-D0101) only prolonged rat ventricular repolarization, and had no effect in human or dog. Inhibition of the IKs (500 nM HMR-1556) and Ito currents (100 µM chromanol-293B) elicited similar effects in all investigated species. We conclude that dog ventricular preparations have the strongest, and rat ventricular preparations have the weakest translational value in cardiac electrophysiological experiments.
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Affiliation(s)
- Tamás Árpádffy-Lovas
- University of Szeged Albert Szent-Györgyi Faculty of Medicine, 37443, Department of Pharmacology and Pharmacotherapy, Szeged, Csongrád, Hungary;
| | - Aiman Saleh A Mohammed
- University of Szeged Albert Szent-Györgyi Faculty of Medicine, 37443, Department of Pharmacology and Pharmacotherapy, Szeged, Csongrád, Hungary;
| | - Muhammad Naveed
- University of Szeged Albert Szent-Györgyi Faculty of Medicine, 37443, Department of Pharmacology and Pharmacotherapy, Szeged, Csongrád, Hungary;
| | - István Koncz
- University of Szeged Albert Szent-Györgyi Faculty of Medicine, 37443, Department of Pharmacology and Pharmacotherapy, Szeged, Csongrád, Hungary;
| | - Beáta Baláti
- University of Szeged Albert Szent-Györgyi Faculty of Medicine, 37443, Department of Pharmacology and Pharmacotherapy, Szeged, Csongrád, Hungary;
| | - Miklós Bitay
- University of Szeged Albert Szent-Györgyi Faculty of Medicine, 37443, Department of Cardiac Surgery, Second Department of Internal Medicine and Cardiology Center, Szeged, Csongrád, Hungary;
| | - Norbert Jost
- University of Szeged Albert Szent-Györgyi Faculty of Medicine, 37443, Department of Pharmacology and Pharmacotherapy, Szeged, Csongrád, Hungary.,Eötvös Loránd Research Network, 579839, ELKH-SZTE Research Group of Cardiovascular Pharmacology, Szeged, Hungary, Budapest, Hungary;
| | - Norbert Nagy
- University of Szeged Albert Szent-Györgyi Faculty of Medicine, 37443, Department of Pharmacology and Pharamacotherapy, Szeged, Csongrád, Hungary.,Eötvös Loránd Research Network, 579839, ELKH-SZTE Research Group of Cardiovascular Pharmacology, Szeged, Hungary, Budapest, Hungary;
| | - István Baczkó
- University of Szeged Albert Szent-Györgyi Faculty of Medicine, 37443, Department of Pharmacology and Pharmacotherapy, Szeged, Csongrád, Hungary;
| | - László Virág
- University of Szeged Albert Szent-Györgyi Faculty of Medicine, 37443, Department of Pharmacology and Pharmacotherapy, Szeged, Csongrád, Hungary;
| | - András Varró
- University of Szeged Albert Szent-Györgyi Faculty of Medicine, 37443, Department of Pharmacology and Pharmacotherapy, Szeged, Csongrád, Hungary.,Eötvös Loránd Research Network, 579839, ELKH-SZTE Research Group of Cardiovascular Pharmacology, Budapest, Hungary;
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12
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Herculano-Houzel S, Rothman DL. From a Demand-Based to a Supply-Limited Framework of Brain Metabolism. Front Integr Neurosci 2022; 16:818685. [PMID: 35431822 PMCID: PMC9012138 DOI: 10.3389/fnint.2022.818685] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2021] [Accepted: 01/10/2022] [Indexed: 12/20/2022] Open
Abstract
What defines the rate of energy use by the brain, as well as per neurons of different sizes in different structures and animals, is one fundamental aspect of neuroscience for which much has been theorized, but very little data are available. The prevalent theories and models consider that energy supply from the vascular system to different brain regions is adjusted both dynamically and in the course of development and evolution to meet the demands of neuronal activity. In this perspective, we offer an alternative view: that regional rates of energy use might be mostly constrained by supply, given the properties of the brain capillary network, the highly stable rate of oxygen delivery to the whole brain under physiological conditions, and homeostatic constraints. We present evidence that these constraints, based on capillary density and tissue oxygen homeostasis, are similar between brain regions and mammalian species, suggesting they derive from fundamental biophysical limitations. The same constraints also determine the relationship between regional rates of brain oxygen supply and usage over the full physiological range of brain activity, from deep sleep to intense sensory stimulation, during which the apparent uncoupling of blood flow and oxygen use is still a predicted consequence of supply limitation. By carefully separating "energy cost" into energy supply and energy use, and doing away with the problematic concept of energetic "demands," our new framework should help shine a new light on the neurovascular bases of metabolic support of brain function and brain functional imaging. We speculate that the trade-offs between functional systems and even the limitation to a single attentional spot at a time might be consequences of a strongly supply-limited brain economy. We propose that a deeper understanding of brain energy supply constraints will provide a new evolutionary understanding of constraints on brain function due to energetics; offer new diagnostic insight to disturbances of brain metabolism; lead to clear, testable predictions on the scaling of brain metabolic cost and the evolution of brains of different sizes; and open new lines of investigation into the microvascular bases of progressive cognitive loss in normal aging as well as metabolic diseases.
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Affiliation(s)
- Suzana Herculano-Houzel
- Department of Psychology, Vanderbilt University, Nashville, TN, United States
- Department of Biological Sciences, Vanderbilt University, Nashville, TN, United States
- Vanderbilt Brain Institute, Vanderbilt University, Nashville, TN, United States
| | - Douglas L. Rothman
- Department of Radiology and Biomedical Imaging, Yale University, New Haven, CT, United States
- Department of Biomedical Engineering, Yale University, New Haven, CT, United States
- Magnetic Resonance Research Center, Yale University, New Haven, CT, United States
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13
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Phenomenological-based model of glucose transport from liver to abdominal subcutaneous adipose tissue. J Theor Biol 2021; 530:110883. [PMID: 34478744 DOI: 10.1016/j.jtbi.2021.110883] [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: 03/03/2021] [Revised: 08/09/2021] [Accepted: 08/23/2021] [Indexed: 11/22/2022]
Abstract
BACKGROUND A good treatment for type 1 diabetes mellitus (T1DM) requires accurate measurements of blood glucose levels. Continuous glucose monitors (CGM) measure the glucose concentration in the interstitial fluid of the abdominal subcutaneous adipose tissue. However, glucose measured in the abdominal interstitial fluid does not represent blood glucose concentrations accurately due to the complex blood transport through the body and glucose diffusion in interstitial fluid. METHODS To gain insight into this problem, a phenomenological-based semiphysical model (PBSM) of glucose transport by volumetric flow and diffusion from the bloodstream to interstitial fluid was constructed. A published 10-step modeling procedure was used to obtain a model for glucose transport time through the blood vessels and from the blood capillaries to the interstitial fluid, glucose diffusion within the interstitial fluid, and glucose diffusion through the semipermeable coating of the sensor needle. For this model, a healthy person is considered at rest with average parameters. RESULTS The simulations performed using the PBSM allow obtaining the glucose transport time from the liver to the sensor needle. In this way, it is possible to reconstruct an accurate dynamic measurement of blood glucose from the measurements in the interstitial fluid of the abdominal subcutaneous adipose tissue. CONCLUSIONS PBSMs with parameters interpretability illustrate the connection of glucose concentrations in the interstitial fluid with that currently in the blood. Implementing this model in a CGM will result in more reliable measurements of blood glucose levels for T1DM treatment.
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14
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Gavrilov VM, Golubeva TB, Bushuev AV. Evolution of metabolic scaling among the tetrapod: Effect of phylogeny, the geologic time of class formation and uniformity of species within a class. Integr Zool 2021; 17:904-917. [PMID: 34751509 DOI: 10.1111/1749-4877.12611] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
The metabolic scaling in the animal has been discussed for over 90 years, but no consensus has been reached. Our analysis of 2,126 species of vertebrates reveals a significant allometric exponent heterogeneity. We show that classes of terrestrial vertebrates exhibit the evolution of metabolic scaling. Both the allometric coefficient "a" and the allometric exponent "b" change naturally, but differently depending on the geological time of group formation. The allometric coefficient "a" shows the measure of the evolutionary development of systems that forms resting metabolism in animals. Endothermic classes, such as birds and mammals, have a metabolic rate that is in an order of magnitude higher than that in ectothermic classes, including amphibians and reptiles. In the terrestrial vertebrate phylogeny, we find that the metabolic scaling is characterized by three main allometric exponent values: b = 3/4 (mammals), b > 3/4 (ectotherms, such as amphibians and reptiles), and b < 3/4 (birds). The heterogeneity of the allometric exponent is a natural phenomenon associated with the general evolution of vertebrates. The scaling factor decreases depending on both the external design and the size (birds vs mammals) of the animal. The metabolic rate and uniformity of species within a class increase as the geological start date of formation of the class approaches the present time. The higher the mass-specific standard metabolic rate in the class, the slower metabolic rate grows with increasing body size in this class. Our results lay the groundwork for further exploration of the evolutionary and ecological aspects of the development of metabolic scaling in animals. This article is protected by copyright. All rights reserved.
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Affiliation(s)
- Valery M Gavrilov
- Department of Vertebrate Zoology, M.V. Lomonosov Moscow State University, Moscow, Russia.,Zvenigorod Biological Station, M.V. Lomonosov Moscow State University, Moscow, Russia
| | - Tatiana B Golubeva
- Department of Vertebrate Zoology, M.V. Lomonosov Moscow State University, Moscow, Russia
| | - Andrey V Bushuev
- Department of Vertebrate Zoology, M.V. Lomonosov Moscow State University, Moscow, Russia
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15
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Jawde SB, Karrobi K, Roblyer D, Vicario F, Herrmann J, Casey D, Lutchen KR, Stamenović D, Bates JHT, Suki B. Inflation instability in the lung: an analytical model of a thick-walled alveolus with wavy fibres under large deformations. J R Soc Interface 2021; 18:20210594. [PMID: 34637644 DOI: 10.1098/rsif.2021.0594] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Inflation of hollow elastic structures can become unstable and exhibit a runaway phenomenon if the tension in their walls does not rise rapidly enough with increasing volume. Biological systems avoid such inflation instability for reasons that remain poorly understood. This is best exemplified by the lung, which inflates over its functional volume range without instability. The goal of this study was to determine how the constituents of lung parenchyma determine tissue stresses that protect alveoli from instability-related overdistension during inflation. We present an analytical model of a thick-walled alveolus composed of wavy elastic fibres, and investigate its pressure-volume behaviour under large deformations. Using second-harmonic generation imaging, we found that collagen waviness follows a beta distribution. Using this distribution to fit human pressure-volume curves, we estimated collagen and elastin effective stiffnesses to be 1247 kPa and 18.3 kPa, respectively. Furthermore, we demonstrate that linearly elastic but wavy collagen fibres are sufficient to achieve inflation stability within the physiological pressure range if the alveolar thickness-to-radius ratio is greater than 0.05. Our model thus identifies the constraints on alveolar geometry and collagen waviness required for inflation stability and provides a multiscale link between alveolar pressure and stresses on fibres in healthy and diseased lungs.
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Affiliation(s)
- Samer Bou Jawde
- Department of Biomedical Engineering, Boston University, 44 Cummington Mall, Boston, MA 02215, USA
| | - Kavon Karrobi
- Department of Biomedical Engineering, Boston University, 44 Cummington Mall, Boston, MA 02215, USA
| | - Darren Roblyer
- Department of Biomedical Engineering, Boston University, 44 Cummington Mall, Boston, MA 02215, USA
| | | | - Jacob Herrmann
- Department of Biomedical Engineering, Boston University, 44 Cummington Mall, Boston, MA 02215, USA
| | - Dylan Casey
- Pulmonary/Critical Care Division, University of Vermont, Burlington, VT, USA
| | - Kenneth R Lutchen
- Department of Biomedical Engineering, Boston University, 44 Cummington Mall, Boston, MA 02215, USA
| | - Dimitrije Stamenović
- Department of Biomedical Engineering, Boston University, 44 Cummington Mall, Boston, MA 02215, USA
| | - Jason H T Bates
- Pulmonary/Critical Care Division, University of Vermont, Burlington, VT, USA
| | - Béla Suki
- Department of Biomedical Engineering, Boston University, 44 Cummington Mall, Boston, MA 02215, USA
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16
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Meyer TW, Hostetter TH. Why Is the GFR So High?: Implications for the Treatment of Kidney Failure. Clin J Am Soc Nephrol 2021; 16:980-987. [PMID: 33303581 PMCID: PMC8216625 DOI: 10.2215/cjn.14300920] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
The high GFR in vertebrates obligates large energy expenditure. Homer Smith's teleologic argument that this high GFR was needed to excrete water as vertebrates evolved in dilute seas is outdated. The GFR is proportional to the metabolic rate among vertebrate species and higher in warm-blooded mammals and birds than in cold-blooded fish, amphibians, and reptiles. The kidney clearance of some solutes is raised above the GFR by tubular secretion, and we presume secretion evolved to eliminate particularly toxic compounds. In this regard, high GFRs may provide a fluid stream into which toxic solutes can be readily secreted. Alternatively, the high GFR may be required to clear solutes that are too large or too varied to be secreted, especially bioactive small proteins and peptides. These considerations have potentially important implications for the understanding and treatment of kidney failure.
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Affiliation(s)
- Timothy W. Meyer
- Departments of Medicine, Veterans Affairs Palo Alto Health Care System and Stanford University, Palo Alto, California
| | - Thomas H. Hostetter
- Department of Medicine, University of North Carolina, Chapel Hill, North Carolina,University of North Carolina Kidney Center, University of North Carolina, Chapel Hill, North Carolina
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17
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Species differences in cardiovascular physiology that affect pharmacology and toxicology. CURRENT OPINION IN TOXICOLOGY 2020. [DOI: 10.1016/j.cotox.2020.07.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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18
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Virot E, Spandan V, Niu L, van Rees WM, Mahadevan L. Elastohydrodynamic Scaling Law for Heart Rates. PHYSICAL REVIEW LETTERS 2020; 125:058102. [PMID: 32794888 DOI: 10.1103/physrevlett.125.058102] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/16/2019] [Accepted: 06/04/2020] [Indexed: 06/11/2023]
Abstract
Animal hearts are soft shells that actively pump blood to oxygenate tissues. Here, we propose an allometric scaling law for the heart rate based on the idea of elastohydrodynamic resonance of a fluid-loaded soft active elastic shell that buckles and contracts axially when twisted periodically. We show that this picture is consistent with numerical simulations of soft cylindrical shells that twist-buckle while pumping a viscous fluid, yielding optimum ejection fractions of 35%-40% when driven resonantly. Our scaling law is consistent with experimental measurements of heart rates over 2 orders of magnitude, and provides a mechanistic basis for how metabolism scales with organism size. In addition to providing a physical rationale for the heart rate and metabolism of an organism, our results suggest a simple design principle for soft fluidic pumps.
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Affiliation(s)
- E Virot
- John A. Paulson School of Engineering and Applied Sciences, Harvard University
| | - V Spandan
- John A. Paulson School of Engineering and Applied Sciences, Harvard University
| | - L Niu
- Department of Physics, Harvard University, Cambridge, Massachusetts 02139, USA
| | - W M van Rees
- Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02138, USA
| | - L Mahadevan
- John A. Paulson School of Engineering and Applied Sciences, Harvard University
- Department of Physics, Harvard University, Cambridge, Massachusetts 02139, USA
- Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, Massachusetts 02138, USA
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19
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Hirose K, Payumo AY, Cutie S, Hoang A, Zhang H, Guyot R, Lunn D, Bigley RB, Yu H, Wang J, Smith M, Gillett E, Muroy SE, Schmid T, Wilson E, Field KA, Reeder DM, Maden M, Yartsev MM, Wolfgang MJ, Grützner F, Scanlan TS, Szweda LI, Buffenstein R, Hu G, Flamant F, Olgin JE, Huang GN. Evidence for hormonal control of heart regenerative capacity during endothermy acquisition. Science 2019; 364:184-188. [PMID: 30846611 DOI: 10.1126/science.aar2038] [Citation(s) in RCA: 218] [Impact Index Per Article: 43.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2017] [Revised: 11/15/2018] [Accepted: 02/21/2019] [Indexed: 12/11/2022]
Abstract
Tissue regenerative potential displays striking divergence across phylogeny and ontogeny, but the underlying mechanisms remain enigmatic. Loss of mammalian cardiac regenerative potential correlates with cardiomyocyte cell-cycle arrest and polyploidization as well as the development of postnatal endothermy. We reveal that diploid cardiomyocyte abundance across 41 species conforms to Kleiber's law-the ¾-power law scaling of metabolism with bodyweight-and inversely correlates with standard metabolic rate, body temperature, and serum thyroxine level. Inactivation of thyroid hormone signaling reduces mouse cardiomyocyte polyploidization, delays cell-cycle exit, and retains cardiac regenerative potential in adults. Conversely, exogenous thyroid hormones inhibit zebrafish heart regeneration. Thus, our findings suggest that loss of heart regenerative capacity in adult mammals is triggered by increasing thyroid hormones and may be a trade-off for the acquisition of endothermy.
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Affiliation(s)
- Kentaro Hirose
- Cardiovascular Research Institute and Department of Physiology, University of California, San Francisco, San Francisco, CA 94158, USA.,Eli and Edythe Broad Center for Regeneration Medicine and Stem Cell Research, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Alexander Y Payumo
- Cardiovascular Research Institute and Department of Physiology, University of California, San Francisco, San Francisco, CA 94158, USA.,Eli and Edythe Broad Center for Regeneration Medicine and Stem Cell Research, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Stephen Cutie
- Cardiovascular Research Institute and Department of Physiology, University of California, San Francisco, San Francisco, CA 94158, USA.,Eli and Edythe Broad Center for Regeneration Medicine and Stem Cell Research, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Alison Hoang
- Cardiovascular Research Institute and Department of Physiology, University of California, San Francisco, San Francisco, CA 94158, USA.,Eli and Edythe Broad Center for Regeneration Medicine and Stem Cell Research, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Hao Zhang
- Department of Medicine, Division of Cardiology, University of California San Francisco, San Francisco, CA 94158, USA
| | - Romain Guyot
- Department of Internal Medicine, Institut de Génomique Fonctionnelle de Lyon, Institut National de la Recherche Agronomique, Université Lyon 1, CNRS, École Normale Superieure de Lyon, 69 007 France
| | - Dominic Lunn
- Cardiovascular Research Institute and Department of Physiology, University of California, San Francisco, San Francisco, CA 94158, USA.,Eli and Edythe Broad Center for Regeneration Medicine and Stem Cell Research, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Rachel B Bigley
- Cardiovascular Research Institute and Department of Physiology, University of California, San Francisco, San Francisco, CA 94158, USA.,Eli and Edythe Broad Center for Regeneration Medicine and Stem Cell Research, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Hongyao Yu
- Epigenetics and Stem Cell Biology Laboratory, National Institute of Environmental Health Sciences, Research Triangle Park, NC 27709, USA
| | - Jiajia Wang
- Epigenetics and Stem Cell Biology Laboratory, National Institute of Environmental Health Sciences, Research Triangle Park, NC 27709, USA
| | - Megan Smith
- Calico Life Sciences, 1170 Veterans Boulevard, South San Francisco, CA 94080, USA
| | - Ellen Gillett
- School of Biological Sciences, University of Adelaide, South Australia, Adelaide 5005, Australia
| | - Sandra E Muroy
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94708, USA
| | - Tobias Schmid
- Helen Wills Neuroscience Institute and Department of Bioengineering, University of California, Berkeley, Berkeley, CA 94708, USA
| | - Emily Wilson
- Department of Medicine, Division of Cardiology, University of California San Francisco, San Francisco, CA 94158, USA
| | - Kenneth A Field
- Department of Biology, Bucknell University, Lewisburg, PA 17837, USA
| | - DeeAnn M Reeder
- Department of Biology, Bucknell University, Lewisburg, PA 17837, USA
| | - Malcom Maden
- Department of Biology and UF Genetics Institute, University of Florida, Gainesville, FL 32611, USA
| | - Michael M Yartsev
- Helen Wills Neuroscience Institute and Department of Bioengineering, University of California, Berkeley, Berkeley, CA 94708, USA
| | - Michael J Wolfgang
- Department of Biological Chemistry, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Frank Grützner
- School of Biological Sciences, University of Adelaide, South Australia, Adelaide 5005, Australia
| | - Thomas S Scanlan
- Department of Physiology and Pharmacology, Oregon Health & Science University, 3181 SW Sam Jackson Park Road, Portland, OR 97239, USA
| | - Luke I Szweda
- Division of Cardiology, University of Texas Southwestern Medical Center, Dallas, TX 75390-8573, USA
| | - Rochelle Buffenstein
- Calico Life Sciences, 1170 Veterans Boulevard, South San Francisco, CA 94080, USA
| | - Guang Hu
- Epigenetics and Stem Cell Biology Laboratory, National Institute of Environmental Health Sciences, Research Triangle Park, NC 27709, USA
| | - Frederic Flamant
- Department of Internal Medicine, Institut de Génomique Fonctionnelle de Lyon, Institut National de la Recherche Agronomique, Université Lyon 1, CNRS, École Normale Superieure de Lyon, 69 007 France
| | - Jeffrey E Olgin
- Cardiovascular Research Institute and Department of Physiology, University of California, San Francisco, San Francisco, CA 94158, USA.,Department of Medicine, Division of Cardiology, University of California San Francisco, San Francisco, CA 94158, USA
| | - Guo N Huang
- Cardiovascular Research Institute and Department of Physiology, University of California, San Francisco, San Francisco, CA 94158, USA. .,Eli and Edythe Broad Center for Regeneration Medicine and Stem Cell Research, University of California, San Francisco, San Francisco, CA 94158, USA
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20
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Wagenseil JE. Reduced amount or integrity of arterial elastic fibers alters allometric scaling exponents for aortic diameter, but not cardiac function in maturing mice. J Biomech Eng 2019; 141:2724664. [PMID: 30729980 DOI: 10.1115/1.4042766] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2018] [Indexed: 01/20/2023]
Abstract
Allometric scaling laws relate physiologic parameters to body weight. Genetically modified mice allow investigation of allometric scaling laws when fundamental cardiovascular components are altered. Elastin haploinsufficient (Eln+/-) mice have reduced elastin amounts and fibulin-5 knockout (Fbln5-/-) mice have compromised elastic fiber integrity in the large arteries which may alter cardiovascular scaling laws. Previously published echocardiography data used to investigate aortic and left ventricular function in Eln+/- and Fbln5-/- mice throughout postnatal development and early adulthood were reanalyzed to determine cardiovascular scaling laws. Aortic diameter, heart weight, stroke volume, and cardiac output have scaling exponents within 1 - 32% of the predicted theoretical range, indicating that the scaling laws apply to maturing mice. For aortic diameter, Eln+/- and Eln+/+ mice have similar scaling exponents, but different scaling constants, suggesting a shift in starting diameter, but no changes in aortic growth with body weight. In contrast, the scaling exponent for aortic diameter in Fbln5-/- mice is lower than Fbln5+/+ mice, but the scaling constant is similar, suggesting that aortic growth with body weight is compromised in Fbln5-/- mice. For both Eln+/- and Fbln5-/- groups, the scaling constant for heart weight is increased compared to the respective control group, suggesting an increase in starting heart weight, but no change in the increase with body weight during maturation. The scaling exponents and constants for stroke volume and cardiac output are not significantly affected by reduced elastin amounts or compromised elastic fiber integrity in the large arteries, highlighting a robust cardiac adaptation despite arterial defects.
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Affiliation(s)
- Jessica E Wagenseil
- Department of Mechanical Engineering and Materials Science, Washington University in St. Louis, St. Louis, MO
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21
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Le TTY, García MR, Nachev M, Grabner D, Balsa-Canto E, Hendriks AJ, Sures B. Development of a PBPK Model for Silver Accumulation in Chub Infected with Acanthocephalan Parasites. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2018; 52:12514-12525. [PMID: 30251844 DOI: 10.1021/acs.est.8b04022] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Simultaneous presence of metals and parasites in fish might lead to potential risks to human health. Parasites might influence metal accumulation and disturb detoxification in fish, thereby affecting biomarkers of fish responses as well as metal biomagnification in humans. It is, therefore, of importance to take into account parasite infection when investigating metal accumulation in fish. However, mechanisms of metal accumulation and distribution in fish-parasite systems are not integrated into current approaches. The present study proposes a new physiologically based pharmacokinetic model for mechanistic simulation of metal partitioning between intestinal parasites and their hosts. As a particular case, Ag accumulation in the system of chub Squalius cephalus and the acanthocephalan Pomphorhynchus tereticollis was investigated. As a novelty, fish cardiac output and organ-specific blood flow distribution were incorporated in our model. This approach distinguishes the current model from the ones developed previously. It also facilitates model extrapolation and application to varying conditions. In general, the model explained Ag accumulation in the system well, especially in chub gill, storage (including skin, muscle, and carcass), and liver. The highest concentration of Ag was found in the liver. The accumulation of Ag in the storage, liver, and gill compartments followed a similar pattern, i.e., increasing during the exposure and decreasing during the depuration. The model also generated this observed trend. However, the model had a weaker performance for simulating Ag accumulation in the intestine and the kidney. Silver accumulation in these organs was less evident with considerable variations.
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Affiliation(s)
- T T Yen Le
- Department of Aquatic Ecology and Centre for Water and Environmental Research (ZWU) , University of Duisburg-Essen , D-45141 Essen , Germany
| | - Míriam R García
- Process Engineering Group , Spanish Council for Scientific Research, IIM-CSIC , 36208 Vigo , Spain
| | - Milen Nachev
- Department of Aquatic Ecology and Centre for Water and Environmental Research (ZWU) , University of Duisburg-Essen , D-45141 Essen , Germany
| | - Daniel Grabner
- Department of Aquatic Ecology and Centre for Water and Environmental Research (ZWU) , University of Duisburg-Essen , D-45141 Essen , Germany
| | - Eva Balsa-Canto
- Process Engineering Group , Spanish Council for Scientific Research, IIM-CSIC , 36208 Vigo , Spain
| | - A Jan Hendriks
- Department of Environmental Science, Faculty of Science , Radboud University Nijmegen , 6525 HP Nijmegen , The Netherlands
| | - Bernd Sures
- Department of Aquatic Ecology and Centre for Water and Environmental Research (ZWU) , University of Duisburg-Essen , D-45141 Essen , Germany
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22
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Andreev-Andrievskiy AA, Popova AS, Lagereva EA, Vinogradova OL. Fluid shift versus body size: changes of hematological parameters and body fluid volume in hindlimb-unloaded mice, rats and rabbits. ACTA ACUST UNITED AC 2018; 221:jeb.182832. [PMID: 29950449 DOI: 10.1242/jeb.182832] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2018] [Accepted: 06/11/2018] [Indexed: 01/12/2023]
Abstract
The cardiovascular system is adapted to gravity, and reactions to the loss of gravity in space are presumably dependent on body size. The dependence of hematological parameters and body fluid volume on simulated microgravity have never been studied as an allometric function before. Thus, we estimated red blood cell (RBC), blood and extracellular fluid volume in hindlimb-unloaded (HLU) or control (attached) mice, rats and rabbits. RBC decrease was found to be size independent, and the allometric dependency for RBC loss in HLU and control animals shared a common power (-0.054±0.008) but a different Y0 coefficient (8.66±0.40 and 10.73±0.49, respectively, P<0.05). Blood volume in HLU animals was unchanged compared with that of controls, disregarding body size. The allometric dependency of interstitial fluid volume in HLU and control mice shared Y0 (1.02±0.09) but had different powers N (0.708±0.017 and 0.648±0.016, respectively, P<0.05), indicating that the interstitial fluid volume increase during hindlimb unloading is more pronounced in larger animals. Our data underscore the importance of size-independent mechanisms of cardiovascular adaptation to weightlessness. Despite the fact that the use of mice hampers application of a straightforward translational approach, this species is useful for gravitational biology as a tool to investigate size-independent mechanisms of mammalian adaptation to microgravity.
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Affiliation(s)
- Alexander A Andreev-Andrievskiy
- Institute of Biomedical Problems, Russian Academy of Sciences, Moscow 123007, Russia .,M.V. Lomonosov Moscow State University, Biology Faculty, Moscow 119991, Russia
| | - Anfisa S Popova
- Institute of Biomedical Problems, Russian Academy of Sciences, Moscow 123007, Russia.,M.V. Lomonosov Moscow State University, Biology Faculty, Moscow 119991, Russia
| | - Evgeniia A Lagereva
- Institute of Biomedical Problems, Russian Academy of Sciences, Moscow 123007, Russia
| | - Olga L Vinogradova
- Institute of Biomedical Problems, Russian Academy of Sciences, Moscow 123007, Russia
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23
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Lillie MA, Vogl AW, Raverty S, Haulena M, McLellan WA, Stenson GB, Shadwick RE. The caval sphincter in cetaceans and its predicted role in controlling venous flow during a dive. ACTA ACUST UNITED AC 2018; 221:jeb.177212. [PMID: 29674378 DOI: 10.1242/jeb.177212] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2018] [Accepted: 04/10/2018] [Indexed: 11/20/2022]
Abstract
A sphincter on the inferior vena cava can protect the heart of a diving mammal from overload when elevated abdominal pressures increase venous return, yet sphincters are reported incompetent or absent in some cetacean species. We previously hypothesized that abdominal pressures are elevated and pulsatile in fluking cetaceans, and that collagen is deposited on the diaphragm according to pressure levels to resist deformation. Here, we tested the hypothesis that cetaceans generating high abdominal pressures need a more robust sphincter than those generating low pressures. We examined diaphragm morphology in seven cetacean and five pinniped species. All odontocetes had morphologically similar sphincters despite large differences in collagen content, and mysticetes had muscle that could modulate caval flow. These findings do not support the hypothesis that sphincter structure correlates with abdominal pressures. To understand why a sphincter is needed, we simulated the impact of oscillating abdominal pressures on caval flow. Under low abdominal pressures, simulated flow oscillated with each downstroke. Under elevated pressures, a vascular waterfall formed, greatly smoothing flow. We hypothesize that cetaceans maintain high abdominal pressures to moderate venous return and protect the heart while fluking, and use their sphincters only during low-fluking periods when abdominal pressures are low. We suggest that pinnipeds, which do not fluke, maintain low abdominal pressures. Simulations also showed that retrograde oscillations could be transmitted upstream from the cetacean abdomen and into the extradural veins, with potentially adverse repercussions for the cerebral circulation. We propose that locomotion-generated pressures have influenced multiple aspects of the cetacean vascular system.
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Affiliation(s)
- Margo A Lillie
- Department of Zoology, University of British Columbia, Vancouver, BC V6T 1Z4, Canada
| | - A Wayne Vogl
- Department of Cellular and Physiological Sciences, University of British Columbia, Vancouver, BC V6T 1Z3, Canada
| | - Stephen Raverty
- Animal Health Centre, 1767 Angus Campbell Road, Abbotsford, BC V3G 2M3, Canada
| | - Martin Haulena
- Vancouver Aquarium Marine Science Centre, PO Box 3232, Vancouver, BC V6G 3E2, Canada
| | - William A McLellan
- Department of Biology and Marine Biology, University of North Carolina Wilmington, Wilmington, NC 28403, USA
| | | | - Robert E Shadwick
- Department of Zoology, University of British Columbia, Vancouver, BC V6T 1Z4, Canada
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24
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van Essen GJ, Te Lintel Hekkert M, Sorop O, Heinonen I, van der Velden J, Merkus D, Duncker DJ. Cardiovascular Function of Modern Pigs Does not Comply with Allometric Scaling Laws. Sci Rep 2018; 8:792. [PMID: 29335617 PMCID: PMC5768797 DOI: 10.1038/s41598-017-18775-z] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2017] [Accepted: 12/18/2017] [Indexed: 12/31/2022] Open
Abstract
Growing concerns have been expressed regarding cardiovascular performance in modern farm pigs, which has been proposed as a critical factor contributing to the reduced adaptability of modern pigs to stress. Here we tested the hypothesis that cardiac dimensions and pump function in modern heavy farm pigs are disproportionally low for their body weight, and investigated potential underlying mechanisms. The results from the present study indeed demonstrate disproportionally low values for stroke volume and cardiac output in pigs with bodyweights over 150 kg. Importantly, these low values were not the result of impaired left ventricular (LV) systolic contractile function, but were due to a disproportionally small LV end-diastolic volume. The latter was associated with changes in determinants of LV passive stiffness, including (i) an increase in LV myocardial collagen, (ii) a shift from the compliant N2BA titin isoform towards the stiff N2B, and (iii) a marked elevation of aortic blood pressure. Taken together, these results demonstrate reduced pumping capacity of the hearts of heavy modern pigs, due to structural abnormalities in the LV myocardium.
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Affiliation(s)
- Gerard J van Essen
- Division of Experimental Cardiology, Department of Cardiology, Thoraxcenter, Cardiovascular Research School COEUR, Erasmus MC, University Medical Center Rotterdam, Rotterdam, The Netherlands
| | - Maaike Te Lintel Hekkert
- Division of Experimental Cardiology, Department of Cardiology, Thoraxcenter, Cardiovascular Research School COEUR, Erasmus MC, University Medical Center Rotterdam, Rotterdam, The Netherlands
| | - Oana Sorop
- Division of Experimental Cardiology, Department of Cardiology, Thoraxcenter, Cardiovascular Research School COEUR, Erasmus MC, University Medical Center Rotterdam, Rotterdam, The Netherlands
| | - Ilkka Heinonen
- Division of Experimental Cardiology, Department of Cardiology, Thoraxcenter, Cardiovascular Research School COEUR, Erasmus MC, University Medical Center Rotterdam, Rotterdam, The Netherlands.,Turku PET Centre, and Department of Clinical Physiology and Nuclear Medicine, University of Turku, Turku, Finland
| | - Jolanda van der Velden
- Department of Physiology, Amsterdam Cardiovascular Sciences, VU University Medical Center, Amsterdam, The Netherlands.,Netherlands Heart Institute, Utrecht, The Netherlands
| | - Daphne Merkus
- Division of Experimental Cardiology, Department of Cardiology, Thoraxcenter, Cardiovascular Research School COEUR, Erasmus MC, University Medical Center Rotterdam, Rotterdam, The Netherlands
| | - Dirk J Duncker
- Division of Experimental Cardiology, Department of Cardiology, Thoraxcenter, Cardiovascular Research School COEUR, Erasmus MC, University Medical Center Rotterdam, Rotterdam, The Netherlands. .,Netherlands Heart Institute, Utrecht, The Netherlands.
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25
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Pulse wave travel distance as a novel marker of ventricular-arterial coupling. Heart Vessels 2017; 33:279-290. [PMID: 28975398 DOI: 10.1007/s00380-017-1058-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/28/2017] [Accepted: 09/22/2017] [Indexed: 01/09/2023]
Abstract
Each stroke volume ejected by the heart is distributed along the arterial system as a pressure waveform. How far the front of the pressure waveform travels within the arterial system depends both on the pulse wave velocity (PWV) and the ejection time (ET). We tested the hypothesis that ET and PWV are coupled together, in order to produce a pulse wave travel distance (PWTD = PWV × ET) which would match the distance from the heart to the most distant site in the arterial system. The study was conducted in 11 healthy volunteers. We recorded lead II of the ECG along with pulse plethysmography at ear, finger and toe. The ET at the ear and pulse arrival time to each peripheral site were extracted. We then calculated PWV followed by PWTD for each location. Taken into account the individual subject variability PWTDToe in the supine position was 153 cm (95% CI 146-160 cm). It was not different from arterial pathway distance from the heart to the toe (D Toe 153 cm). The PWTDFinger and PWTDEar were longer than the distance from the heart to the finger and ear irrespective of body position. ETEar and PWVToe appear to be coupled in healthy subjects to produce a PWTD that is roughly equivalent to the arterial pathway distance to the toe. We propose that PWTD should be evaluated further to test its potential as a noninvasive parameter of ventricular-arterial coupling in subjects with cardiovascular diseases.
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26
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Parsons SP, Huizinga JD. The phase response and state space of slow wave contractions in the small intestine. Exp Physiol 2017; 102:1118-1132. [DOI: 10.1113/ep086373] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2017] [Accepted: 06/29/2017] [Indexed: 12/28/2022]
Affiliation(s)
- Sean P. Parsons
- Farncombe Family Digestive Health Research Institute; McMaster University; Hamilton Ontario Canada
| | - Jan D. Huizinga
- Farncombe Family Digestive Health Research Institute; McMaster University; Hamilton Ontario Canada
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27
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Boyer DM, Kirk EC, Silcox MT, Gunnell GF, Gilbert CC, Yapuncich GS, Allen KL, Welch E, Bloch JI, Gonzales LA, Kay RF, Seiffert ER. Internal carotid arterial canal size and scaling in Euarchonta: Re-assessing implications for arterial patency and phylogenetic relationships in early fossil primates. J Hum Evol 2016; 97:123-44. [DOI: 10.1016/j.jhevol.2016.06.002] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2016] [Revised: 06/03/2016] [Accepted: 06/04/2016] [Indexed: 01/31/2023]
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28
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Nguyen PH, Tuzun E, Quick CM. Aortic pulse pressure homeostasis emerges from physiological adaptation of systemic arteries to local mechanical stresses. Am J Physiol Regul Integr Comp Physiol 2016; 311:R522-31. [PMID: 27306830 DOI: 10.1152/ajpregu.00402.2015] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2015] [Accepted: 06/13/2016] [Indexed: 11/22/2022]
Abstract
Aortic pulse pressure arises from the interaction of the heart, the systemic arterial system, and peripheral microcirculations. The complex interaction between hemodynamics and arterial remodeling precludes the ability to experimentally ascribe changes in aortic pulse pressure to particular adaptive responses. Therefore, the purpose of the present work was to use a human systemic arterial system model to test the hypothesis that pulse pressure homeostasis can emerge from physiological adaptation of systemic arteries to local mechanical stresses. First, we assumed a systemic arterial system that had a realistic topology consisting of 121 arterial segments. Then the relationships of pulsatile blood pressures and flows in arterial segments were characterized by standard pulse transmission equations. Finally, each arterial segment was assumed to remodel to local stresses following three simple rules: 1) increases in endothelial shear stress increases radius, 2) increases in wall circumferential stress increases wall thickness, and 3) increases in wall circumferential stress decreases wall stiffness. Simulation of adaptation by iteratively calculating pulsatile hemodynamics, mechanical stresses, and vascular remodeling led to a general behavior in response to mechanical perturbations: initial increases in pulse pressure led to increased arterial compliances, and decreases in pulse pressure led to decreased compliances. Consequently, vascular adaptation returned pulse pressures back toward baseline conditions. This behavior manifested when modeling physiological adaptive responses to changes in cardiac output, changes in peripheral resistances, and changes in local arterial radii. The present work, thus, revealed that pulse pressure homeostasis emerges from physiological adaptation of systemic arteries to local mechanical stresses.
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Affiliation(s)
- Phuc H Nguyen
- Michael E. DeBakey Institute, Texas A&M University, College Station, Texas; and
| | - Egemen Tuzun
- Texas A&M Institute for Preclinical Studies, College Station, Texas
| | - Christopher M Quick
- Michael E. DeBakey Institute, Texas A&M University, College Station, Texas; and
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