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Cole JE, Dadone L, Rao S, Bapodra-Villaverde P, Schilz A, Johnston M. Venous blood gas and lactate values in adult giraffe trained for voluntary jugular phlebotomy. Zoo Biol 2024; 43:371-375. [PMID: 38566545 DOI: 10.1002/zoo.21831] [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: 05/09/2023] [Revised: 02/23/2024] [Accepted: 03/18/2024] [Indexed: 04/04/2024]
Abstract
Blood gas analyses have previously been performed for giraffe under anesthesia and with physical restraint in a chute; however, reference values for giraffe that are trained to participate in venipuncture without chemical or physical restraint have not previously been described. Using a point-of-care blood gas and lactate analyzer and 20 giraffe trained for voluntary phlebotomy, values were determined for venous blood gasses and plasma lactate concentration. Ninety-five percent confidence in the mean values for venous pH (7.34-7.46), partial pressure of carbon dioxide (PCO2; 28.5-37.8 mmHg), partial pressure of oxygen (PO2; 56-102 mmHg), bicarbonate (HCO3 -; 18.9-21.0 mmol/L), base excess (BE; -6.0 to -3.6 mmol/L), total carbon dioxide (TCO2; 19.9-22.0 mmol/L), and lactate (0.32-0.56 mmol/L) were calculated. This is the first report on venous blood gas analysis values for giraffe without chemical or physical restraint. These data will provide a reference for clinical interpretation of venous blood gas and lactate values in giraffe and demonstrate some of the potential diagnostic benefits to training giraffe and other zoo species for voluntary medical procedures.
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Affiliation(s)
| | - Liza Dadone
- Cheyenne Mountain Zoo, Colorado Springs, Colorado, USA
| | - Sangeeta Rao
- Colorado State University, Fort Collins, Colorado, USA
| | | | - Amy Schilz
- Cheyenne Mountain Zoo, Colorado Springs, Colorado, USA
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2
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Paulson OB, Schousboe A, Hultborn H. The history of Danish neuroscience. Eur J Neurosci 2023; 58:2893-2960. [PMID: 37477973 DOI: 10.1111/ejn.16062] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2022] [Revised: 05/04/2023] [Accepted: 05/29/2023] [Indexed: 07/22/2023]
Abstract
The history of Danish neuroscience starts with an account of impressive contributions made at the 17th century. Thomas Bartholin was the first Danish neuroscientist, and his disciple Nicolaus Steno became internationally one of the most prominent neuroscientists in this period. From the start, Danish neuroscience was linked to clinical disciplines. This continued in the 19th and first half of the 20th centuries with new initiatives linking basic neuroscience to clinical neurology and psychiatry in the same scientific environment. Subsequently, from the middle of the 20th century, basic neuroscience was developing rapidly within the preclinical university sector. Clinical neuroscience continued and was even reinforced during this period with important translational research and a close co-operation between basic and clinical neuroscience. To distinguish 'history' from 'present time' is not easy, as many historical events continue in present time. Therefore, we decided to consider 'History' as new major scientific developments in Denmark, which were launched before the end of the 20th century. With this aim, scientists mentioned will have been born, with a few exceptions, no later than the early 1960s. However, we often refer to more recent publications in documenting the developments of initiatives launched before the end of the last century. In addition, several scientists have moved to Denmark after the beginning of the present century, and they certainly are contributing to the present status of Danish neuroscience-but, again, this is not the History of Danish neuroscience.
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Affiliation(s)
- Olaf B Paulson
- Neurobiology Research Unit, Department of Neurology, Rigshospitalet, 9 Blegdamsvej, Copenhagen, Denmark
- Department of Clinical Medicine, University of Copenhagen, Copenhagen, Denmark
| | - Arne Schousboe
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Hans Hultborn
- Department of Neuroscience, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
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3
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Aalkjær C, Wang T. The cardiovascular challenges in giraffes. J Muscle Res Cell Motil 2023; 44:53-60. [PMID: 35879488 DOI: 10.1007/s10974-022-09626-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2022] [Accepted: 07/10/2022] [Indexed: 11/30/2022]
Abstract
Giraffes are the highest living animals on Earth and therefore are challenged by gravity more than any other species. In particular the cardiovascular system needs to adapt to this challenge. Giraffes have a mean blood pressure around 200 mmHg, which ensures a mean arterial pressure near the head of 100 mmHg when the giraffe is standing with the neck in a near vertical position. This immediately raises several questions. How do giraffes avoid edema in the legs where the arterial pressure is 300 mmHg or higher? How does the heart produce a pressure of 200 mmHg, and what is the energy required for this endeavor? How can the kidney tolerate a pressure of about 200 mmHg and does this mean that giraffes have a high glomerular filtration rate? What is the arterial pressure in the head of giraffes when they drink, and how is perfusion of the brain maintained when they lift their head after drinking? In this short review, we present some answers to these questions.
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Affiliation(s)
- Christian Aalkjær
- Department of Biomedicine, Aarhus University, 8000, Aarhus C, Denmark.
- Department of Biomedical Sciences, University of Copenhagen, Copenhagen, Denmark.
| | - Tobias Wang
- Zoophysiology, Department of Biological Sciences, Aarhus University, 8000, Aarhus C, Denmark
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4
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Trimmel NE, Podgoršak A, Oertel MF, Jucker S, Arras M, Schmid Daners M, Weisskopf M. Venous dynamics in anesthetized sheep govern postural-induced changes in cerebrospinal fluid pressure comparable to those in humans. Physiol Rep 2022; 10:e15525. [PMID: 36541216 PMCID: PMC9768641 DOI: 10.14814/phy2.15525] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2022] [Revised: 11/01/2022] [Accepted: 11/11/2022] [Indexed: 06/17/2023] Open
Abstract
Sheep are popular large animals in which to model human disorders and to study physiological processes such as cerebrospinal fluid dynamics. However, little is known about vascular compensatory mechanisms affecting cerebrospinal fluid pressures during acute postural changes in sheep. Six female white Alpine sheep were anesthetized to investigate the interactions of the vascular and cerebrospinal fluid system by acquiring measurements of intracranial pressure and central and jugular venous pressure during passive postural changes induced by a tilt table. The cross-sectional area of the common jugular vein and venous blood flow velocity was recorded. Anesthetized sheep showed bi-phasic effects of postural changes on intracranial pressure during tilting. A marked collapse of the jugular vein was observed during head-over-body tilting; this is in accordance with findings in humans. Active regulatory effects of the arterial system on maintaining cerebral perfusion pressure were observed independent of tilting direction. Conclusion: Anesthetized sheep show venous dynamics in response to posture-induced changes in intracranial pressure that are comparable with those in humans.
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Affiliation(s)
- Nina Eva Trimmel
- Center for Surgical ResearchUniversity Hospital Zurich, University of ZurichZurichSwitzerland
| | - Anthony Podgoršak
- Department of Mechanical and Process Engineering, ETH ZurichZurichSwitzerland
| | - Markus Florian Oertel
- Department of NeurosurgeryUniversity Hospital Zurich, University of ZurichZurichSwitzerland
| | - Simone Jucker
- Center for Surgical ResearchUniversity Hospital Zurich, University of ZurichZurichSwitzerland
| | - Margarete Arras
- Center for Surgical ResearchUniversity Hospital Zurich, University of ZurichZurichSwitzerland
| | | | - Miriam Weisskopf
- Center for Surgical ResearchUniversity Hospital Zurich, University of ZurichZurichSwitzerland
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5
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A Preliminary Study on the Siphon Mechanism in Giraffe ( Giraffa camelopardalis). Animals (Basel) 2022; 12:ani12233348. [PMID: 36496868 PMCID: PMC9740075 DOI: 10.3390/ani12233348] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2022] [Revised: 11/23/2022] [Accepted: 11/26/2022] [Indexed: 12/04/2022] Open
Abstract
Adult giraffes reach heights of 4.5 m with a heart-to-head distance of over 2 m, making cranial blood supply challenging. Ultrasound confirmed that the giraffe jugular vein collapses during head movement from ground level to fully erect, negating the possibility of a siphon mechanism in the neck. We showed that a short-length siphon structure over a simulated head-to-heart distance for a giraffe significantly influences flow in a collapsible tube. The siphon structure is determined according to brain case measurements. The short-length siphon structure in a shorter-necked ostrich showed no significant increase in flow. The shorter head-to-heart distance might be the reason for the lack of effect in ostriches. A siphon mechanism situated in the cranium is certainly possible, with a significant effect exerted on the amount of pressure the heart must generate to allow adequate cranial blood perfusion in a long-necked giraffe. The study validated that a cranial-bound siphon structure can operate and will be of significant value for adequate cranial blood perfusion in long-necked species such as giraffes and might also have existed in extinct species of long-necked dinosaurs.
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6
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Nishiyama A, Kitada K, Suzuki M. Blood pressure adaptation in vertebrates: Comparative biology. Kidney Int 2022; 102:242-247. [PMID: 35671910 DOI: 10.1016/j.kint.2022.03.032] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2022] [Revised: 03/18/2022] [Accepted: 03/30/2022] [Indexed: 11/26/2022]
Abstract
With evolution from water to land, the osmotic regulation of body fluids and cardiovascular systems of vertebrates evolved to cope with dryness and gravity. While aquatic vertebrates can use buoyancy to compensate for the effects of gravity, terrestrial vertebrates cannot, and must circulate blood throughout their body - a necessity that likely led to the development of strong hearts and high blood pressure. These changes may be supported by anatomical evolution of the cardiovascular system and by functional evolution, with alterations in hormonal systems. Thus, during the evolution of terrestrial animals, increased performance of body functions to endure harsher environments was required, necessitating increased blood pressure. In an age of overeating and insufficient exercise, modern man does not fully utilize the high levels of physical functions acquired through evolution. Drastic changes in our living environment cause hypertension, the pathogenesis of which remains unknown. To survive in new environments, as might be expected in outer space or underwater, an understanding is required of how changes in blood pressure have occurred that enabled adaptation through evolution in vertebrates.
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Affiliation(s)
- Akira Nishiyama
- Department of Pharmacology, Faculty of Medicine, Kagawa University, Kagawa, Japan.
| | - Kento Kitada
- Department of Pharmacology, Faculty of Medicine, Kagawa University, Kagawa, Japan
| | - Miwa Suzuki
- Department of Marine Science and Resources, College of Bioresource Sciences, Nihon University, Fujisawa, Japan
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7
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Natterson-Horowitz B, Baccouche BM, Mary J, Shivkumar T, Bertelsen MF, Aalkjær C, Smerup MH, Ajijola OA, Hadaya J, Wang T. Did giraffe cardiovascular evolution solve the problem of heart failure with preserved ejection fraction? EVOLUTION MEDICINE AND PUBLIC HEALTH 2021; 9:248-255. [PMID: 34447575 PMCID: PMC8385250 DOI: 10.1093/emph/eoab016] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/29/2020] [Accepted: 06/04/2021] [Indexed: 11/18/2022]
Abstract
The evolved adaptations of other species can be a source of insight for novel biomedical innovation. Limitations of traditional animal models for the study of some pathologies are fueling efforts to find new approaches to biomedical investigation. One emerging approach recognizes the evolved adaptations in other species as possible solutions to human pathology. The giraffe heart, for example, appears resistant to pathology related to heart failure with preserved ejection fraction (HFpEF)—a leading form of hypertension-associated cardiovascular disease in humans. Here, we postulate that the physiological pressure-induced left ventricular thickening in giraffes does not result in the pathological cardiovascular changes observed in humans with hypertension. The mechanisms underlying this cardiovascular adaptation to high blood pressure in the giraffe may be a bioinspired roadmap for preventive and therapeutic strategies for human HFpEF.
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Affiliation(s)
- Barbara Natterson-Horowitz
- Department of Medicine, Harvard Medical School, Boston, MA, USA.,Department of Human Evolutionary Biology, Harvard University, Cambridge, MA, USA.,Division of Cardiology, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA
| | - Basil M Baccouche
- Department of Human Evolutionary Biology, Harvard University, Cambridge, MA, USA.,Department of Public Health and Primary Care, University of Cambridge, Cambridge, UK
| | - Jennifer Mary
- Zoobiquity Research Initiative at UCLA, Los Angeles, CA 90024, USA
| | | | | | | | - Morten H Smerup
- Department of Cardiothoracic Surgery, Copenhagen University Hospital, Rigshospitalet, Copenhagen, Denmark
| | - Olujimi A Ajijola
- UCLA Cardiac Arrhythmia Center, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA
| | - Joseph Hadaya
- UCLA Cardiac Arrhythmia Center, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA.,Molecular, Cellular and Integrative Physiology Program, UCLA, Los Angeles, CA, USA
| | - Tobias Wang
- Zoophysiology, Department of Biology, Aarhus University, Aarhus, Denmark
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8
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Liu C, Gao J, Cui X, Li Z, Chen L, Yuan Y, Zhang Y, Mei L, Zhao L, Cai D, Hu M, Zhou B, Li Z, Qin T, Si H, Li G, Lin Z, Xu Y, Zhu C, Yin Y, Zhang C, Xu W, Li Q, Wang K, Gilbert MTP, Heller R, Wang W, Huang J, Qiu Q. A towering genome: Experimentally validated adaptations to high blood pressure and extreme stature in the giraffe. SCIENCE ADVANCES 2021; 7:7/12/eabe9459. [PMID: 33731352 PMCID: PMC7968835 DOI: 10.1126/sciadv.abe9459] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/30/2020] [Accepted: 02/02/2021] [Indexed: 05/02/2023]
Abstract
The suite of adaptations associated with the extreme stature of the giraffe has long interested biologists and physiologists. By generating a high-quality chromosome-level giraffe genome and a comprehensive comparison with other ruminant genomes, we identified a robust catalog of giraffe-specific mutations. These are primarily related to cardiovascular, bone growth, vision, hearing, and circadian functions. Among them, the giraffe FGFRL1 gene is an outlier with seven unique amino acid substitutions not found in any other ruminant. Gene-edited mice with the giraffe-type FGFRL1 show exceptional hypertension resistance and higher bone mineral density, both of which are tightly connected with giraffe adaptations to high stature. Our results facilitate a deeper understanding of the molecular mechanism underpinning distinct giraffe traits, and may provide insights into the study of hypertension in humans.
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Affiliation(s)
- Chang Liu
- School of Ecology and Environment, Northwestern Polytechnical University, Xi'an 710072, China
| | - Jianbo Gao
- Department of Orthopaedics, Xijing Hospital, The Fourth Military Medical University, Xi'an 710032, China
| | - Xinxin Cui
- School of Ecology and Environment, Northwestern Polytechnical University, Xi'an 710072, China
| | - Zhipeng Li
- College of Animal Science and Technology, Jilin Agricultural University, Changchun 130118, China
| | - Lei Chen
- School of Ecology and Environment, Northwestern Polytechnical University, Xi'an 710072, China
| | - Yuan Yuan
- School of Ecology and Environment, Northwestern Polytechnical University, Xi'an 710072, China
| | - Yaolei Zhang
- BGI-Qingdao, BGI-Shenzhen, Qingdao 266555, China
| | - Liangwei Mei
- Department of Orthopaedics, Xijing Hospital, The Fourth Military Medical University, Xi'an 710032, China
| | - Lan Zhao
- Shaanxi Key Laboratory for Animal Conservation, College of Life Sciences, Xi'an 710069, China
| | - Dan Cai
- BGI-Qingdao, BGI-Shenzhen, Qingdao 266555, China
| | - Mingliang Hu
- School of Ecology and Environment, Northwestern Polytechnical University, Xi'an 710072, China
| | - Botong Zhou
- School of Ecology and Environment, Northwestern Polytechnical University, Xi'an 710072, China
| | - Zihe Li
- School of Ecology and Environment, Northwestern Polytechnical University, Xi'an 710072, China
| | - Tao Qin
- School of Ecology and Environment, Northwestern Polytechnical University, Xi'an 710072, China
| | - Huazhe Si
- College of Animal Science and Technology, Jilin Agricultural University, Changchun 130118, China
| | - Guangyu Li
- College of Animal Science and Technology, Jilin Agricultural University, Changchun 130118, China
| | - Zeshan Lin
- School of Ecology and Environment, Northwestern Polytechnical University, Xi'an 710072, China
| | - Yicheng Xu
- Jiaxing SynBioLab. Co. Ltd., Jiaxing 314000, China
| | - Chenglong Zhu
- School of Ecology and Environment, Northwestern Polytechnical University, Xi'an 710072, China
| | - Yuan Yin
- School of Ecology and Environment, Northwestern Polytechnical University, Xi'an 710072, China
| | - Chenzhou Zhang
- School of Ecology and Environment, Northwestern Polytechnical University, Xi'an 710072, China
| | - Wenjie Xu
- School of Ecology and Environment, Northwestern Polytechnical University, Xi'an 710072, China
| | - Qingjie Li
- Research Center of Traditional Chinese Medicine, The Affiliated Hospital to Changchun University of Chinese Medicine, Changchun 130021, China
| | - Kun Wang
- School of Ecology and Environment, Northwestern Polytechnical University, Xi'an 710072, China
| | - M Thomas P Gilbert
- Center for Evolutionary Hologenomics, GLOBE Institute, University of Copenhagen, Øster Voldgade 5-7, Copenhagen 1350, Denmark
- Norwegian University of Science and Technology, University Museum, 7491 Trondheim, Norway
| | - Rasmus Heller
- Section for Computational and RNA Biology, Department of Biology, University of Copenhagen, Copenhagen N 2200, Denmark.
| | - Wen Wang
- School of Ecology and Environment, Northwestern Polytechnical University, Xi'an 710072, China.
- Center for Excellence in Animal Evolution and Genetics, Chinese Academy of Sciences, Kunming 650223, China
| | - Jinghui Huang
- Department of Orthopaedics, Xijing Hospital, The Fourth Military Medical University, Xi'an 710032, China.
| | - Qiang Qiu
- School of Ecology and Environment, Northwestern Polytechnical University, Xi'an 710072, China.
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9
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Abstract
Gravity affects the physiology of many animals, and the effect is, for good reason, most pronounced in tall species. The physiology-in particular, cardiovascular function-of giraffes has therefore captivated the interest of physiologists for centuries. Several studies document high mean arterial blood pressure of giraffes of about 200 mm Hg. This appears necessary to establish a cerebral perfusion pressure on the order of 100 mm Hg at the cranial end of the carotid arteries. Here, we discuss the unique characteristics of blood vessels, the heart, and the kidney of giraffes and how these functional and structural adaptations are related to very high blood pressure. We also discuss how the cerebral circulation of giraffes is established and what we know about how the blood flow and arterial and venous pressures in giraffes change when they stop to drink and subsequently lift their heads 5-6 m in one sweeping movement.
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Affiliation(s)
- Christian Aalkjær
- Department of Biomedicine, Aarhus University, Aarhus C 8000, Denmark; .,Department of Biomedical Sciences, University of Copenhagen, Copenhagen 2200, Denmark
| | - Tobias Wang
- Department of Biology, Aarhus University, Aarhus C 8000, Denmark;
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10
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Michel JB. Phylogenic Determinants of Cardiovascular Frailty, Focus on Hemodynamics and Arterial Smooth Muscle Cells. Physiol Rev 2020; 100:1779-1837. [DOI: 10.1152/physrev.00022.2019] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
The evolution of the circulatory system from invertebrates to mammals has involved the passage from an open system to a closed in-parallel system via a closed in-series system, accompanying the increasing complexity and efficiency of life’s biological functions. The archaic heart enables pulsatile motion waves of hemolymph in invertebrates, and the in-series circulation in fish occurs with only an endothelium, whereas mural smooth muscle cells appear later. The present review focuses on evolution of the circulatory system. In particular, we address how and why this evolution took place from a closed, flowing, longitudinal conductance at low pressure to a flowing, highly pressurized and bifurcating arterial compartment. However, although arterial pressure was the latest acquired hemodynamic variable, the general teleonomy of the evolution of species is the differentiation of individual organ function, supported by specific fueling allowing and favoring partial metabolic autonomy. This was achieved via the establishment of an active contractile tone in resistance arteries, which permitted the regulation of blood supply to specific organ activities via its localized function-dependent inhibition (active vasodilation). The global resistance to viscous blood flow is the peripheral increase in frictional forces caused by the tonic change in arterial and arteriolar radius, which backscatter as systemic arterial blood pressure. Consequently, the arterial pressure gradient from circulating blood to the adventitial interstitium generates the unidirectional outward radial advective conductance of plasma solutes across the wall of conductance arteries. This hemodynamic evolution was accompanied by important changes in arterial wall structure, supported by smooth muscle cell functional plasticity, including contractility, matrix synthesis and proliferation, endocytosis and phagocytosis, etc. These adaptive phenotypic shifts are due to epigenetic regulation, mainly related to mechanotransduction. These paradigms actively participate in cardio-arterial pathologies such as atheroma, valve disease, heart failure, aneurysms, hypertension, and physiological aging.
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11
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Ogoh S, Washio T, Paton JFR, Fisher JP, Petersen LG. Gravitational effects on intracranial pressure and blood flow regulation in young men: a potential shunting role for the external carotid artery. J Appl Physiol (1985) 2020; 129:901-908. [PMID: 32816640 DOI: 10.1152/japplphysiol.00369.2020] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
We sought to determine whether gravity-induced changes in intracranial pressure influence cerebral blood flow regulation. Accordingly, nine young healthy men were studied while supine (0°) and during mild changes in hydrostatic pressure induced by head-up tilt at +20° and +10° (HUT+20 and HUT+10) and head-down tilt at -20° and -10° (HDT-20, HDT-10). Blood flows were measured in the internal and external carotid and vertebral arteries (ICA, ECA, and VA). Intraocular pressure (IOP) was measured as an indicator of hydrostatic changes in intracranial pressure. A posture change from HUT+20 to HDT-20 increased IOP by +5.1 ± 1.9 mmHg (P < 0.001) and ECA blood flow (from 61.7 ± 26.1 to 87.6 ± 46.4 mL/min, P = 0.004) but did not affect ICA (P = 0.528) or VA (P = 0.101) blood flow. The increase in ECA flow correlated with the tilt angle and resultant changes in intracranial pressures (by IOP), thus indicating a passive hydrostatic gravitational dependence (r = 0.371, P = 0.012). On the contrary, ICA flow remained constant and thus well protected against moderate orthostatic stress. When ICA flow was corrected for the gravitational changes in intracranial pressures (by IOP), it demonstrated the same magnitude of gravitational dependence as ECA. These findings suggest that passive hydrostatic increases in intracranial pressure outbalance the concurrent increase in arterial feeding pressure to the brain and thus prevent cerebral hyperperfusion during HDT. The mechanism for maintaining constant cerebral flow was by increased ECA flow, thus supporting the role of these vascular beds as a shunting pathway.NEW & NOTEWORTHY We investigated whether gravity-induced changes in intracranial pressure influence cerebral blood flow regulation in young men. We recorded extra- and intracerebral blood flow during changes in posture, and data indicate that the external carotid artery may serve as an overflow pathway to prevent cerebral hyperperfusion during increases in cerebral arterial blood pressure.
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Affiliation(s)
- Shigehiko Ogoh
- Department of Biomedical Engineering, Toyo University, Kawagoe-Shi, Saitama, Japan
| | - Takuro Washio
- Department of Biomedical Engineering, Toyo University, Kawagoe-Shi, Saitama, Japan.,Japan Society for the Promotion of Science, Tokyo, Japan
| | - Julian F R Paton
- Department of Physiology, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand
| | - James P Fisher
- Department of Physiology, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand
| | - Lonnie G Petersen
- Department of Biomedical Science, Faculty of Health Science, University of Copenhagen, Copenhagen, Denmark.,Department of Radiology, University of California, San Diego, California.,Department of Mechanical and Aerospace Engineering, University of California, San Diego, California
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12
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Muller Z, Lee DE, Scheijen CPJ, Strauss MKL, Carter KD, Deacon F. Giraffe translocations: A review and discussion of considerations. Afr J Ecol 2020. [DOI: 10.1111/aje.12727] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Affiliation(s)
- Zoe Muller
- School of Biological Sciences Life Sciences Building University of Bristol Bristol UK
- Giraffe Research & Conservation Trust Nairobi Kenya
| | - Derek E. Lee
- Wild Nature Institute Concord NH USA
- Mueller Laboratory Department of Biology Pennsylvania State University State College PA USA
| | - Ciska P. J. Scheijen
- Wildlife and Grassland Sciences University of the Free State Bloemfontein South Africa
- Rockwood Conservation Griekwastad South Africa
| | | | - Kerryn D. Carter
- Elephant Connection Kavango Zambezi Transfrontier Conservation Area Mwandi Zambia
| | - Francois Deacon
- Wildlife and Grassland Sciences University of the Free State Bloemfontein South Africa
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13
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Lauridsen H, Gonzales S, Hedwig D, Perrin KL, Williams CJA, Wrege PH, Bertelsen MF, Pedersen M, Butcher JT. Extracting physiological information in experimental biology via Eulerian video magnification. BMC Biol 2019; 17:103. [PMID: 31831016 PMCID: PMC6907275 DOI: 10.1186/s12915-019-0716-7] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2019] [Accepted: 10/30/2019] [Indexed: 12/13/2022] Open
Abstract
BACKGROUND Videographic material of animals can contain inapparent signals, such as color changes or motion that hold information about physiological functions, such as heart and respiration rate, pulse wave velocity, and vocalization. Eulerian video magnification allows the enhancement of such signals to enable their detection. The purpose of this study is to demonstrate how signals relevant to experimental physiology can be extracted from non-contact videographic material of animals. RESULTS We applied Eulerian video magnification to detect physiological signals in a range of experimental models and in captive and free ranging wildlife. Neotenic Mexican axolotls were studied to demonstrate the extraction of heart rate signal of non-embryonic animals from dedicated videographic material. Heart rate could be acquired both in single and multiple animal setups of leucistic and normally colored animals under different physiological conditions (resting, exercised, or anesthetized) using a wide range of video qualities. Pulse wave velocity could also be measured in the low blood pressure system of the axolotl as well as in the high-pressure system of the human being. Heart rate extraction was also possible from videos of conscious, unconstrained zebrafish and from non-dedicated videographic material of sand lizard and giraffe. This technique also allowed for heart rate detection in embryonic chickens in ovo through the eggshell and in embryonic mice in utero and could be used as a gating signal to acquire two-phase volumetric micro-CT data of the beating embryonic chicken heart. Additionally, Eulerian video magnification was used to demonstrate how vocalization-induced vibrations can be detected in infrasound-producing Asian elephants. CONCLUSIONS Eulerian video magnification provides a technique to extract inapparent temporal signals from videographic material of animals. This can be applied in experimental and comparative physiology where contact-based recordings (e.g., heart rate) cannot be acquired.
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Affiliation(s)
- Henrik Lauridsen
- Nancy E. and Peter C. Meinig School of Biomedical Engineering, Cornell University, 304 Weill Hall, Ithaca, NY 14853-7202 USA
- Department of Clinical Medicine, Aarhus University, Palle Juul-Jensens Boulevard 99, 8200 Aarhus N, Denmark
| | - Selina Gonzales
- Nancy E. and Peter C. Meinig School of Biomedical Engineering, Cornell University, 304 Weill Hall, Ithaca, NY 14853-7202 USA
- California State University, 333 S Twin Oaks Valley Rd, San Marcos, CA 92096 USA
| | - Daniela Hedwig
- Cornell Lab of Ornithology, Cornell University, 159 Sapsucker Woods Road, Ithaca, NY 14850 USA
| | - Kathryn L. Perrin
- Center for Zoo and Wild Animal Health, Copenhagen Zoo, Roskildevej 32, 2000 Frederiksberg, Denmark
- Department of Veterinary Clinical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Dyrlægevej 6, 1870 Frederiksberg C, Denmark
| | - Catherine J. A. Williams
- Center for Zoo and Wild Animal Health, Copenhagen Zoo, Roskildevej 32, 2000 Frederiksberg, Denmark
- Department of Bioscience, Aarhus University, C.F. Møllers Allé 3, 8000 Aarhus C, Denmark
| | - Peter H. Wrege
- Cornell Lab of Ornithology, Cornell University, 159 Sapsucker Woods Road, Ithaca, NY 14850 USA
| | - Mads F. Bertelsen
- Center for Zoo and Wild Animal Health, Copenhagen Zoo, Roskildevej 32, 2000 Frederiksberg, Denmark
- Department of Veterinary Clinical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Dyrlægevej 6, 1870 Frederiksberg C, Denmark
| | - Michael Pedersen
- Department of Clinical Medicine, Aarhus University, Palle Juul-Jensens Boulevard 99, 8200 Aarhus N, Denmark
| | - Jonathan T. Butcher
- Nancy E. and Peter C. Meinig School of Biomedical Engineering, Cornell University, 304 Weill Hall, Ithaca, NY 14853-7202 USA
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14
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Yoshiga C, Dawson EA, Volianitis S, Warberg J, Secher NH. Cardiac output during exercise is related to plasma atrial natriuretic peptide but not to central venous pressure in humans. Exp Physiol 2019; 104:379-384. [DOI: 10.1113/ep087522] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2018] [Accepted: 01/22/2019] [Indexed: 11/08/2022]
Affiliation(s)
- Chie Yoshiga
- Department of Anaesthesia; The Copenhagen Muscle Research Centre, Rigshospitalet; University of Copenhagen; Copenhagen Denmark
| | - Ellen Adele Dawson
- Department of Anaesthesia; The Copenhagen Muscle Research Centre, Rigshospitalet; University of Copenhagen; Copenhagen Denmark
- Faculty of Science; School of Sport and Exercise Sciences; Liverpool John Moores University; Liverpool UK
| | - Stefanos Volianitis
- Department of Anaesthesia; The Copenhagen Muscle Research Centre, Rigshospitalet; University of Copenhagen; Copenhagen Denmark
- Department of Health Science and Technology; Aalborg University; Aalborg Denmark
| | - Jørgen Warberg
- Department of Biomedicine; The Panum Institute; University of Copenhagen; Copenhagen Denmark
| | - Niels H. Secher
- Department of Anaesthesia; The Copenhagen Muscle Research Centre, Rigshospitalet; University of Copenhagen; Copenhagen Denmark
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15
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Izwan A, Snelling EP, Seymour RS, Meyer LCR, Fuller A, Haw A, Mitchell D, Farrell AP, Costello MA, Maloney SK. Ameliorating the adverse cardiorespiratory effects of chemical immobilization by inducing general anaesthesia in sheep and goats: implications for physiological studies of large wild mammals. J Comp Physiol B 2018; 188:991-1003. [PMID: 30232543 DOI: 10.1007/s00360-018-1184-z] [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: 05/11/2018] [Revised: 08/28/2018] [Accepted: 09/11/2018] [Indexed: 10/28/2022]
Abstract
Chemical immobilization is necessary for the physiological study of large wild animals. However, the immobilizing drugs can adversely affect the cardiovascular and respiratory systems, yielding data that do not accurately represent the normal, resting state. We hypothesize that these adverse effects can be ameliorated by reversing the immobilizing agent while holding the animal under general anaesthesia. We used habituated sheep Ovis aries (N = 5, 46.9 ± 5.3 kg body mass, mean ± SEM) and goats Capra hircus (N = 4, 27.7 ± 2.8 kg) as ungulate models for large wild animals, and measured their cardiorespiratory function under three conditions: (1) mild sedation (midazolam), as a proxy for the normal resting state, (2) immobilization (etorphine and azaperone), and (3) general anaesthesia (propofol) followed by etorphine antagonism (naltrexone). Cardiac output for both sheep and goats remained unchanged across the three conditions (overall means of 6.2 ± 0.9 and 3.3 ± 0.3 L min-1, respectively). For both sheep and goats, systemic and pulmonary mean arterial pressures were significantly altered from initial midazolam levels when administered etorphine + azaperone, but those arterial pressures were restored upon transition to propofol anaesthesia and antagonism of the etorphine. Under etorphine + azaperone, minute ventilation decreased in the sheep, though this decrease was corrected under propofol, while the minute ventilation in the goats remained unchanged throughout. Under etorphine + azaperone, both sheep and goats displayed arterial blood hypoxia and hypercapnia (relative to midazolam levels), which failed to completely recover under propofol, indicating that more time might be needed for the blood gases to be adequately restored. Nonetheless, many of the confounding cardiorespiratory effects of etorphine were ameliorated when it was antagonized with naltrexone while the animal was held under propofol, indicating that this procedure can largely restore the cardiovascular and respiratory systems closer to a normal, resting state.
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Affiliation(s)
- Adian Izwan
- School of Human Sciences, University of Western Australia, 35 Stirling Hwy, Crawley, Western Australia, Australia.
| | - Edward P Snelling
- Brain Function Research Group, School of Physiology, University of the Witwatersrand, Johannesburg, South Africa
| | - Roger S Seymour
- School of Biological Sciences, University of Adelaide, Adelaide, South Australia, Australia
| | - Leith C R Meyer
- Brain Function Research Group, School of Physiology, University of the Witwatersrand, Johannesburg, South Africa.,Department of Paraclinical Sciences, University of Pretoria, Pretoria, South Africa
| | - Andrea Fuller
- Brain Function Research Group, School of Physiology, University of the Witwatersrand, Johannesburg, South Africa.,Department of Paraclinical Sciences, University of Pretoria, Pretoria, South Africa
| | - Anna Haw
- Brain Function Research Group, School of Physiology, University of the Witwatersrand, Johannesburg, South Africa
| | - Duncan Mitchell
- School of Human Sciences, University of Western Australia, 35 Stirling Hwy, Crawley, Western Australia, Australia.,Brain Function Research Group, School of Physiology, University of the Witwatersrand, Johannesburg, South Africa
| | - Anthony P Farrell
- Department of Zoology, University of British Columbia, Vancouver, British Columbia, Canada.,Faculty of Land and Food Systems, University of British Columbia, Vancouver, British Columbia, Canada
| | - Mary-Ann Costello
- Central Animal Service, University of the Witwatersrand, Johannesburg, South Africa
| | - Shane K Maloney
- School of Human Sciences, University of Western Australia, 35 Stirling Hwy, Crawley, Western Australia, Australia.,Brain Function Research Group, School of Physiology, University of the Witwatersrand, Johannesburg, South Africa
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16
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Poulsen CB, Wang T, Assersen K, Iversen NK, Damkjaer M. Does mean arterial blood pressure scale with body mass in mammals? Effects of measurement of blood pressure. Acta Physiol (Oxf) 2018; 222:e13010. [PMID: 29210189 DOI: 10.1111/apha.13010] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2017] [Revised: 11/28/2017] [Accepted: 11/28/2017] [Indexed: 01/21/2023]
Abstract
For at least the last 30 years, it has been discussed whether mean arterial blood pressure (MAP) is independent of body mass or whether it increases in accordance with the vertical height between the heart and the brain. The debate has centred on the most appropriate mathematical models for analysing allometric scaling and phylogenetic relationships; there has been previously little focus on evaluating the validity of underlying physiological data. Currently, the 2 most comprehensive scaling analyses are based on data from 47 species of mammals, based on 114 references. We reviewed all available references to determine under which physiological conditions MAP had been recorded. In 44 (38.6%) of the cited references, MAP was measured in anaesthetized animals. Data from conscious animals were reported in 59 (51.8%) of references; of these, 3 (2.6%) were radiotelemetric studies. In 5 species, data were reported from both anaesthetized and conscious animals, and the mean difference in the MAP between these settings was 20 ± 29 mm Hg. From a literature search, we identified MAP measurements performed by radiotelemetry in 11 of the 47 species included in the meta-analyses. A Bland-Altman analysis showed a bias of 1 mm Hg with 95% confidence interval (from -35 to 36 mm Hg); that is, the limits of agreement between radiotelemetric studies and studies in restrained animals were double the supposed difference in the MAP between the mouse and elephant. In conclusion, the existing literature does not provide evidence for either a positive or neutral scaling of arterial pressure to body mass across taxa.
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Affiliation(s)
- C. B. Poulsen
- Department of Cardiology; Regional Hospital West Jutland; Herning Denmark
| | - T. Wang
- Department of Zoophysiology; Aarhus University; Aarhus Denmark
| | - K. Assersen
- Department of Cardiovascular and Renal Research; University of Southern Denmark; Odense Denmark
| | - N. K. Iversen
- Department of Zoophysiology; Aarhus University; Aarhus Denmark
- Center for Functionally Integrative Neuroscience; Institute of Clinical Medicine; Aarhus University; Aarhus C Denmark
| | - M. Damkjaer
- Department of Cardiovascular and Renal Research; University of Southern Denmark; Odense Denmark
- Department of Paediatrics; Kolding Hospital; Kolding Denmark
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17
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Kondoh D, Nakamura KG, Ono YS, Yuhara K, Bando G, Watanabe K, Horiuchi N, Kobayashi Y, Sasaki M, Kitamura N. Histological features of the vomeronasal organ in the giraffe, Giraffa camelopardalis. Microsc Res Tech 2017; 80:652-656. [PMID: 28094892 DOI: 10.1002/jemt.22843] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2016] [Revised: 12/25/2016] [Accepted: 01/05/2017] [Indexed: 11/07/2022]
Abstract
The vomeronasal organ (VNO) that preferentially detects species-specific substances is diverse among animal species, and its morphological properties seem to reflect the ecological features of animals. This histological study of two female reticulated giraffes (Giraffa camelopardalis reticulata) found that the VNO is developed in giraffes. The lateral and medial regions of the vomeronasal lumen were covered with sensory and nonsensory epithelia, respectively. The vomeronasal glands were positive for periodic acid-Schiff and alcian blue (pH 2.5) stains. The VNO comprises several large veins like others in the order Cetartiodactyla, suggesting that these veins function in a pumping mechanism in this order. In addition, numerous thin-walled vessels located immediately beneath the epithelia covering the lumen entirely surrounded the vomeronasal lumen. This sponge-like structure might function as a specific secondary pump in giraffes.
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Affiliation(s)
- Daisuke Kondoh
- Laboratory of Veterinary Anatomy, Obihiro University of Agriculture and Veterinary Medicine, Nishi 2-11 Inada-cho, Obihiro, 080-8555, Japan
| | - Kentaro G Nakamura
- Laboratory of Veterinary Anatomy, Obihiro University of Agriculture and Veterinary Medicine, Nishi 2-11 Inada-cho, Obihiro, 080-8555, Japan
| | - Yurie S Ono
- Laboratory of Veterinary Anatomy, Obihiro University of Agriculture and Veterinary Medicine, Nishi 2-11 Inada-cho, Obihiro, 080-8555, Japan
| | | | - Gen Bando
- Asahiyama Zoo, Asahikawa, 078-8205, Japan
| | - Kenichi Watanabe
- Veterinary Pathology, Obihiro University of Agriculture and Veterinary Medicine, Nishi 2-11 Inada-cho, Obihiro, 080-8555, Japan
| | - Noriyuki Horiuchi
- Veterinary Pathology, Obihiro University of Agriculture and Veterinary Medicine, Nishi 2-11 Inada-cho, Obihiro, 080-8555, Japan
| | - Yoshiyasu Kobayashi
- Veterinary Pathology, Obihiro University of Agriculture and Veterinary Medicine, Nishi 2-11 Inada-cho, Obihiro, 080-8555, Japan
| | - Motoki Sasaki
- Laboratory of Veterinary Anatomy, Obihiro University of Agriculture and Veterinary Medicine, Nishi 2-11 Inada-cho, Obihiro, 080-8555, Japan
| | - Nobuo Kitamura
- Laboratory of Veterinary Anatomy, Obihiro University of Agriculture and Veterinary Medicine, Nishi 2-11 Inada-cho, Obihiro, 080-8555, Japan
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18
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Crossley DA, Burggren WW, Reiber CL, Altimiras J, Rodnick KJ. Mass Transport: Circulatory System with Emphasis on Nonendothermic Species. Compr Physiol 2016; 7:17-66. [PMID: 28134997 DOI: 10.1002/cphy.c150010] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Mass transport can be generally defined as movement of material matter. The circulatory system then is a biological example given its role in the movement in transporting gases, nutrients, wastes, and chemical signals. Comparative physiology has a long history of providing new insights and advancing our understanding of circulatory mass transport across a wide array of circulatory systems. Here we focus on circulatory function of nonmodel species. Invertebrates possess diverse convection systems; that at the most complex generate pressures and perform at a level comparable to vertebrates. Many invertebrates actively modulate cardiovascular function using neuronal, neurohormonal, and skeletal muscle activity. In vertebrates, our understanding of cardiac morphology, cardiomyocyte function, and contractile protein regulation by Ca2+ highlights a high degree of conservation, but differences between species exist and are coupled to variable environments and body temperatures. Key regulators of vertebrate cardiac function and systemic blood pressure include the autonomic nervous system, hormones, and ventricular filling. Further chemical factors regulating cardiovascular function include adenosine, natriuretic peptides, arginine vasotocin, endothelin 1, bradykinin, histamine, nitric oxide, and hydrogen sulfide, to name but a few. Diverse vascular morphologies and the regulation of blood flow in the coronary and cerebral circulations are also apparent in nonmammalian species. Dynamic adjustments of cardiovascular function are associated with exercise on land, flying at high altitude, prolonged dives by marine mammals, and unique morphology, such as the giraffe. Future studies should address limits of gas exchange and convective transport, the evolution of high arterial pressure across diverse taxa, and the importance of the cardiovascular system adaptations to extreme environments. © 2017 American Physiological Society. Compr Physiol 7:17-66, 2017.
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Affiliation(s)
- Dane A Crossley
- Department of Biological Sciences, University of North Texas, Denton, Texas, USA
| | - Warren W Burggren
- Department of Biological Sciences, University of North Texas, Denton, Texas, USA
| | - Carl L Reiber
- School of Life Sciences, University of Nevada Las Vegas, Las Vegas, Nevada, USA
| | - Jordi Altimiras
- AVIAN Behavioral Genomics and Physiology, IFM Biology, Linköping University, Linköping, Sweden
| | - Kenneth J Rodnick
- Department of Biological Sciences, Idaho State University, Pocatello, Idaho, USA
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19
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Dong B, Wang Z, Ma J. Leg-to-trunk ratio and the risk of hypertension in children and adolescents: a population-based study. J Public Health (Oxf) 2016; 38:688-695. [PMID: 28158765 DOI: 10.1093/pubmed/fdv203] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Affiliation(s)
| | | | - Jun Ma
- Institute of Child and Adolescent Health, School of Public Health, Peking University Health Science Center, Beijing 100191, China
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20
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Abstract
Cardiovascular function in dinosaurs can be inferred from fossil evidence with knowledge of how metabolic rate, blood flow rate, blood pressure, and heart size are related to body size in living animals. Skeletal stature and nutrient foramen size in fossil femora provide direct evidence of a high arterial blood pressure, a large four-chambered heart, a high aerobic metabolic rate, and intense locomotion. But was the heart of a huge, long-necked sauropod dinosaur able to pump blood up 9 m to its head?
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Affiliation(s)
- Roger S. Seymour
- School of Biological Sciences, University of Adelaide, Adelaide, Australia
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21
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Telinius N, Brøgger T, Skovgaard N, Bek T, Aalkjaer C. Tone regulation in giraffe retinal arterioles. Acta Ophthalmol 2016; 94:e523-4. [PMID: 26806534 DOI: 10.1111/aos.12958] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Niklas Telinius
- Department of Biomedicine; Aarhus University; Aarhus Denmark
- Department of Ophthalmology; Aarhus University Hospital; Aarhus Denmark
| | | | - Nini Skovgaard
- Section for Zoophysiology; Department of Bioscience; Aarhus University; Aarhus Denmark
| | - Toke Bek
- Department of Ophthalmology; Aarhus University Hospital; Aarhus Denmark
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22
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Ramoshaba N, Monyeki K, Hay L. Components of Height and Blood Pressure among Ellisras Rural Children: Ellisras Longitudinal Study. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2016; 13:ijerph13090856. [PMID: 27618907 PMCID: PMC5036689 DOI: 10.3390/ijerph13090856] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/17/2016] [Revised: 08/16/2016] [Accepted: 08/24/2016] [Indexed: 11/16/2022]
Abstract
To date, there has been no study done investigating the relationship between the components of height and blood pressure (BP) in rural South African children. Therefore, the aim of this study was to investigate the relationship between height, sitting height (SH), leg length (LL), and SH-to-height ratio (SH/H) with BP in Ellisras rural children. All children underwent anthropometric and BP measurements using standard procedure. Linear regression was used to assess the relationship between height, SH, LL, SH/H, and BP. The regression showed a positive significant (p < 0.001) association between systolic BP (SBP) with height and SH (β ranged from 0.127 to 0.134 and 95% CI ranged from 0.082 to 0.415). Diastolic BP (DBP) also showed a positive significant (p < 0.001) association with height and SH (β ranged from 0.080 to 0.088 and 95% CI ranged from 0.042 to 0.259). After having been adjusted for age, gender, body mass index, and waist circumference, DBP showed a positive significant (p < 0.05) association with height. There was a positive significant association between DBP and SBP together with the components of height amongst Ellisras rural children.
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Affiliation(s)
- Nthai Ramoshaba
- Department of Physiology and Environmental Health, University of Limpopo, Polokwane 0700, South Africa.
| | - Kotsedi Monyeki
- Department of Physiology and Environmental Health, University of Limpopo, Polokwane 0700, South Africa.
| | - Leon Hay
- Department of Physiology, Sefako Makgatho Health Science University, Pretoria 0001, South Africa.
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23
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Volianitis S, Secher NH. Cardiovascular control during whole body exercise. J Appl Physiol (1985) 2016; 121:376-90. [PMID: 27311439 PMCID: PMC5007320 DOI: 10.1152/japplphysiol.00674.2015] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2015] [Accepted: 06/10/2016] [Indexed: 12/25/2022] Open
Abstract
It has been considered whether during whole body exercise the increase in cardiac output is large enough to support skeletal muscle blood flow. This review addresses four lines of evidence for a flow limitation to skeletal muscles during whole body exercise. First, even though during exercise the blood flow achieved by the arms is lower than that achieved by the legs (∼160 vs. ∼385 ml·min(-1)·100 g(-1)), the muscle mass that can be perfused with such flow is limited by the capacity to increase cardiac output (42 l/min, highest recorded value). Secondly, activation of the exercise pressor reflex during fatiguing work with one muscle group limits flow to other muscle groups. Another line of evidence comes from evaluation of regional blood flow during exercise where there is a discrepancy between flow to a muscle group when it is working exclusively and when it works together with other muscles. Finally, regulation of peripheral resistance by sympathetic vasoconstriction in active muscles by the arterial baroreflex is critical for blood pressure regulation during exercise. Together, these findings indicate that during whole body exercise muscle blood flow is subordinate to the control of blood pressure.
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Affiliation(s)
- Stefanos Volianitis
- Department of Health Science and Technology, Aalborg University, Aalborg, Denmark; and
| | - Niels H Secher
- The Copenhagen Muscle Research Center, Department of Anesthesiology, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark
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24
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Agaba M, Ishengoma E, Miller WC, McGrath BC, Hudson CN, Bedoya Reina OC, Ratan A, Burhans R, Chikhi R, Medvedev P, Praul CA, Wu-Cavener L, Wood B, Robertson H, Penfold L, Cavener DR. Giraffe genome sequence reveals clues to its unique morphology and physiology. Nat Commun 2016; 7:11519. [PMID: 27187213 PMCID: PMC4873664 DOI: 10.1038/ncomms11519] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2015] [Accepted: 04/01/2016] [Indexed: 11/12/2022] Open
Abstract
The origins of giraffe's imposing stature and associated cardiovascular adaptations are unknown. Okapi, which lacks these unique features, is giraffe's closest relative and provides a useful comparison, to identify genetic variation underlying giraffe's long neck and cardiovascular system. The genomes of giraffe and okapi were sequenced, and through comparative analyses genes and pathways were identified that exhibit unique genetic changes and likely contribute to giraffe's unique features. Some of these genes are in the HOX, NOTCH and FGF signalling pathways, which regulate both skeletal and cardiovascular development, suggesting that giraffe's stature and cardiovascular adaptations evolved in parallel through changes in a small number of genes. Mitochondrial metabolism and volatile fatty acids transport genes are also evolutionarily diverged in giraffe and may be related to its unusual diet that includes toxic plants. Unexpectedly, substantial evolutionary changes have occurred in giraffe and okapi in double-strand break repair and centrosome functions. Giraffe's unique anatomy and physiology include its stature and associated cardiovascular adaptation. Here, Douglas Cavener and colleagues provide de novo genome assemblies of giraffe and its closest relative okapi and provide comparative analyses to infer insights into evolution and adaptation.
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Affiliation(s)
- Morris Agaba
- School of Life Sciences and Bioengineering, African Institute of Science and Technology, Arusha 4222, Tanzania.,Biosciences Eastern and Central Africa, International Livestock Research Institute, Nairobi GPO00100, Kenya.,Center for Genomics and Bioinformatics, Department of Biology, Huck Institutes of the Life Sciences, Pennsylvania State University, University Park, Pennsylvania 16802, USA
| | - Edson Ishengoma
- School of Life Sciences and Bioengineering, African Institute of Science and Technology, Arusha 4222, Tanzania
| | - Webb C Miller
- Center for Genomics and Bioinformatics, Department of Biology, Huck Institutes of the Life Sciences, Pennsylvania State University, University Park, Pennsylvania 16802, USA
| | - Barbara C McGrath
- Center for Genomics and Bioinformatics, Department of Biology, Huck Institutes of the Life Sciences, Pennsylvania State University, University Park, Pennsylvania 16802, USA
| | - Chelsea N Hudson
- Center for Genomics and Bioinformatics, Department of Biology, Huck Institutes of the Life Sciences, Pennsylvania State University, University Park, Pennsylvania 16802, USA
| | - Oscar C Bedoya Reina
- Center for Genomics and Bioinformatics, Department of Biology, Huck Institutes of the Life Sciences, Pennsylvania State University, University Park, Pennsylvania 16802, USA.,MRC Functional Genomics Unit, Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford OX1 3PT, UK
| | - Aakrosh Ratan
- Center for Genomics and Bioinformatics, Department of Biology, Huck Institutes of the Life Sciences, Pennsylvania State University, University Park, Pennsylvania 16802, USA.,Center for Public Health Genomics, Department of Computer Science, University of Virginia, Charlottesville, Virginia 22908, USA
| | - Rico Burhans
- Center for Genomics and Bioinformatics, Department of Biology, Huck Institutes of the Life Sciences, Pennsylvania State University, University Park, Pennsylvania 16802, USA
| | - Rayan Chikhi
- Center for Genomics and Bioinformatics, Department of Computer Science and Engineering, Huck Institutes of the Life Sciences, Pennsylvania State University, University Park, Pennsylvania 16802, USA.,Department of Biochemistry and Molecular Biology, Pennsylvania State University, University Park, Pennsylvania 16802, USA
| | - Paul Medvedev
- Center for Genomics and Bioinformatics, Department of Computer Science and Engineering, Huck Institutes of the Life Sciences, Pennsylvania State University, University Park, Pennsylvania 16802, USA.,Department of Biochemistry and Molecular Biology, Pennsylvania State University, University Park, Pennsylvania 16802, USA
| | - Craig A Praul
- Huck Institutes of the Life Sciences, Pennsylvania State University, University Park, Pennsylvania 16802, USA
| | - Lan Wu-Cavener
- Center for Genomics and Bioinformatics, Department of Biology, Huck Institutes of the Life Sciences, Pennsylvania State University, University Park, Pennsylvania 16802, USA
| | - Brendan Wood
- Center for Genomics and Bioinformatics, Department of Biology, Huck Institutes of the Life Sciences, Pennsylvania State University, University Park, Pennsylvania 16802, USA
| | | | | | - Douglas R Cavener
- School of Life Sciences and Bioengineering, African Institute of Science and Technology, Arusha 4222, Tanzania.,Center for Genomics and Bioinformatics, Department of Biology, Huck Institutes of the Life Sciences, Pennsylvania State University, University Park, Pennsylvania 16802, USA
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25
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Arvedsen SK, Eiken O, Kölegård R, Petersen LG, Norsk P, Damgaard M. Body height and arterial pressure in seated and supine young males during +2 G centrifugation. Am J Physiol Regul Integr Comp Physiol 2015; 309:R1172-7. [DOI: 10.1152/ajpregu.00524.2014] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2014] [Accepted: 08/17/2015] [Indexed: 11/22/2022]
Abstract
It is known that arterial pressure correlates positively with body height in males, and it has been suggested that this is due to the increasing vertical hydrostatic gradient from the heart to the carotid baroreceptors. Therefore, we tested the hypothesis that a higher gravito-inertial stress induced by the use of a human centrifuge would increase mean arterial pressure (MAP) more in tall than in short males in the seated position. In short (162–171 cm; n = 8) and tall (194–203 cm; n = 10) healthy males (18–41 yr), brachial arterial pressure, heart rate (HR), and cardiac output were measured during +2G centrifugation, while they were seated upright with the legs kept horizontal (+2Gz). In a separate experiment, the same measurements were done with the subjects supine (+2Gx). During +2Gz MAP increased in the short (22 ± 2 mmHg, P < 0.0001) and tall (23 ± 2 mmHg, P < 0.0001) males, with no significant difference between the groups. HR increased more ( P < 0.05) in the tall than in the short group (14 ± 2 vs. 7 ± 2 bpm). Stroke volume (SV) decreased in the short group (26 ± 4 ml, P = 0.001) and more so in the tall group (39 ± 5 ml, P < 0.0001; short vs. tall, P = 0.047). During +2Gx, systolic arterial pressure increased ( P < 0.001) and SV ( P = 0.012) decreased in the tall group only. In conclusion, during +2Gz, MAP increased in both short and tall males, with no difference between the groups. However, in the tall group, HR increased more during +2Gz, which could be caused by a larger hydrostatic pressure gradient from heart to head, leading to greater inhibition of the carotid baroreceptors.
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Affiliation(s)
- Sine K. Arvedsen
- Department of Biomedical Sciences, Faculty of Health Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Ola Eiken
- Department of Environmental Physiology, Swedish Aerospace Physiology Centre, Royal Institute of Technology, Stockholm, Sweden; and
| | - Roger Kölegård
- Department of Environmental Physiology, Swedish Aerospace Physiology Centre, Royal Institute of Technology, Stockholm, Sweden; and
| | - Lonnie G. Petersen
- Department of Biomedical Sciences, Faculty of Health Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Peter Norsk
- Department of Biomedical Sciences, Faculty of Health Sciences, University of Copenhagen, Copenhagen, Denmark
- Division of Space Life Sciences, Universities Space Research Association and Biomedical Research and Environmental Sciences Division, NASA Johnson Space Center, Houston, Texas; and
| | - Morten Damgaard
- Department of Biomedical Sciences, Faculty of Health Sciences, University of Copenhagen, Copenhagen, Denmark
- Department of Clinical Physiology and Nuclear Medicine, Centre for Functional Imaging and Research, Hvidovre Hospital, Hvidovre, Denmark
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26
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Damkjaer M, Wang T, Brøndum E, Østergaard KH, Baandrup U, Hørlyck A, Hasenkam JM, Smerup M, Funder J, Marcussen N, Danielsen CC, Bertelsen MF, Grøndahl C, Pedersen M, Agger P, Candy G, Aalkjaer C, Bie P. The giraffe kidney tolerates high arterial blood pressure by high renal interstitial pressure and low glomerular filtration rate. Acta Physiol (Oxf) 2015; 214:497-510. [PMID: 26010805 DOI: 10.1111/apha.12531] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2015] [Revised: 05/11/2015] [Accepted: 05/18/2015] [Indexed: 12/11/2022]
Abstract
BACKGROUND The tallest animal on earth, the giraffe (Giraffa camelopardalis) is endowed with a mean arterial blood pressure (MAP) twice that of other mammals. The kidneys reside at heart level and show no sign of hypertension-related damage. We hypothesized that a species-specific evolutionary adaption in the giraffe kidney allows normal for size renal haemodynamics and glomerular filtration rate (GFR) despite a MAP double that of other mammals. METHODS Fourteen anaesthetized giraffes were instrumented with vascular and bladder catheters to measure glomerular filtration rate (GFR) and effective renal plasma flow (ERPF). Renal interstitial hydrostatic pressure (RIHP) was assessed by inserting a needle into the medullary parenchyma. Doppler ultrasound measurements provided renal artery resistive index (RI). Hormone concentrations as well as biomechanical, structural and histological characteristics of vascular and renal tissues were determined. RESULTS GFR averaged 342 ± 99 mL min(-1) and ERPF 1252 ± 305 mL min(-1) . RIHP varied between 45 and 140 mmHg. Renal pelvic pressure was 39 ± 2 mmHg and renal venous pressure 32 ± 4 mmHg. A valve-like structure at the junction of the renal and vena cava generated a pressure drop of 12 ± 2 mmHg. RI was 0.27. The renal capsule was durable with a calculated burst pressure of 600 mmHg. Plasma renin and AngII were 2.6 ± 0.5 mIU L(-1) and 9.1 ± 1.5 pg mL(-1) respectively. CONCLUSION In giraffes, GFR, ERPF and RI appear much lower than expected based on body mass. A strong renal capsule supports a RIHP, which is >10-fold that of other mammals effectively reducing the net filtration pressure and protecting against the high MAP.
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Affiliation(s)
- M. Damkjaer
- Department of Cardiovascular and Renal Research; University of Southern Denmark; Odense Denmark
| | - T. Wang
- Department of Biological Sciences; Institute of Zoophysiology; Aarhus University; Aarhus Denmark
| | - E. Brøndum
- Department of Physiology; Institute of Biomedicine; Aarhus University; Aarhus Denmark
| | - K. H. Østergaard
- Centre for Clinical Research; Hjørring/Department of Clinical Medicine; Aalborg University; Denmark
| | - U. Baandrup
- Centre for Clinical Research; Hjørring/Department of Clinical Medicine; Aalborg University; Denmark
| | - A. Hørlyck
- Department of Radiology; Aarhus University Hospital; Aarhus Denmark
| | - J. M. Hasenkam
- Department of Cardiothoracic and Vascular Surgery; Institute of Clinical Medicine; Aarhus University Hospital; Aarhus Denmark
| | - M. Smerup
- Department of Cardiothoracic and Vascular Surgery; Institute of Clinical Medicine; Aarhus University Hospital; Aarhus Denmark
| | - J. Funder
- Department of Cardiothoracic and Vascular Surgery; Institute of Clinical Medicine; Aarhus University Hospital; Aarhus Denmark
| | - N. Marcussen
- Department of Clinical Pathology; University of Southern Denmark; Odense Denmark
| | - C. C. Danielsen
- Department of Anatomy; Institute of Biomedicine; Aarhus University; Aarhus Denmark
| | - M. F. Bertelsen
- Center for Zoo and Wild Animal Health; Copenhagen Zoo; Copenhagen Denmark
| | - C. Grøndahl
- Center for Zoo and Wild Animal Health; Copenhagen Zoo; Copenhagen Denmark
| | - M. Pedersen
- MR Research Centre; Institute of Clinical Medicine; Aarhus University Hospital; Aarhus Denmark
| | - P. Agger
- MR Research Centre; Institute of Clinical Medicine; Aarhus University Hospital; Aarhus Denmark
| | - G. Candy
- Department of Physiology and Medicine; University of the Witwatersrand; Johannesburg South Africa
| | - C. Aalkjaer
- Department of Physiology; Institute of Biomedicine; Aarhus University; Aarhus Denmark
- Department of Biomedicine; University of Copenhagen; Copenhagen Denmark
| | - P. Bie
- Department of Cardiovascular and Renal Research; University of Southern Denmark; Odense Denmark
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Bertelsen MF. Giraffidae. FOWLER'S ZOO AND WILD ANIMAL MEDICINE, VOLUME 8 2015. [PMCID: PMC7151920 DOI: 10.1016/b978-1-4557-7397-8.00061-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
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Smerup M, Damkjær M, Brøndum E, Baandrup UT, Kristiansen SB, Nygaard H, Aalkjær C, Sauer C, Buchanan R, Bertelsen MF, Østergaard K, Grøndahl C, Candy G, Hasenkam JM, Secher NH, Bie P, Wang T. The thick left ventricular wall of the giraffe heart normalises wall tension, but limits stroke volume and cardiac output. J Exp Biol 2015; 219:457-63. [DOI: 10.1242/jeb.132753] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2015] [Accepted: 11/06/2015] [Indexed: 11/20/2022]
Abstract
Giraffes – the tallest extant animals on Earth – are renowned for their high central arterial blood pressure, which is necessary to secure brain perfusion. The pressure which may exceed 300 mmHg has historically been attributed to an exceptionally large heart. Recently, this has been refuted by several studies demonstrating that the mass of giraffe heart is similar to that of other mammals when expressed relative to body mass. It remains enigmatic, however, how the normal-sized giraffe heart generates such massive arterial pressures.
We hypothesized that giraffe hearts have a small intraventricular cavity and a relatively thick ventricular wall, allowing for generation of high arterial pressures at normal left ventricular wall tension. In nine anaesthetized giraffes (495±38 kg), we determined in vivo ventricular dimensions using echocardiography along with intraventricular and aortic pressures to calculate left ventricular wall stress. Cardiac output was also determined by inert gas rebreathing to provide an additional and independent estimate of stroke volume. Echocardiography and inert gas-rebreathing yielded similar cardiac outputs of 16.1±2.5 and 16.4±1.4 l min−1, respectively. End-diastolic and end-systolic volumes were 521±61 ml and 228±42 ml, yielding an ejection fraction of 56±4%, and a stroke volume of 0.59 ml kg−1. Left ventricular circumferential wall stress was 7.83±1.76 kPa. We conclude that, relative to body mass, a small left ventricular cavity and a low stroke volume characterizes the giraffe heart. The adaptations result in typical mammalian left ventricular wall tensions, but results in lowered cardiac output.
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Affiliation(s)
- Morten Smerup
- Department of Cardiothoracic Surgery, Rigshospitalet, Copenhagen, Denmark and Clinical Institute, Aarhus University, Aarhus, Denmark
| | - Mads Damkjær
- Hans Christian Andersen Children's Hospital, Odense, Denmark
- Department of Cardiovascular and Renal Research, University of Southern Denmark, Odense, Denmark
| | - Emil Brøndum
- Department of Biomedicine, Aarhus University, Aarhus, and Department of Biomedicine, Copenhagen University, Copenhagen, Denmark
| | - Ulrik T. Baandrup
- Department of Pathology, Center for Clinical Research, Vendsyssel Hospital, Aalborg University, Aalborg, Denmark
| | | | - Hans Nygaard
- Department of Thoracic and Cardiovascular Surgery and Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
| | - Christian Aalkjær
- Department of Biomedicine, Aarhus University, Aarhus, and Department of Biomedicine, Copenhagen University, Copenhagen, Denmark
| | - Cathrine Sauer
- Centre for Zoo and Wild Animal Health, Copenhagen Zoo, Frederiksberg C, Denmark
| | - Rasmus Buchanan
- Zoophysiology, Department of Biological Sciences, Aarhus University, Aarhus C, Denmark
| | | | - Kristine Østergaard
- Department of Pathology, Center for Clinical Research, Vendsyssel Hospital, Aalborg University, Aalborg, Denmark
| | - Carsten Grøndahl
- Centre for Zoo and Wild Animal Health, Copenhagen Zoo, Frederiksberg C, Denmark
| | - Geoffrey Candy
- Department of Physiology and Medicine, University of the Witwatersrand, Johannesburg, South Africa
| | - J. Michael Hasenkam
- Department of Thoracic and Cardiovascular Surgery and Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
| | - Niels H. Secher
- Department of Anesthesiology, Rigshospitalet, Copenhagen, Denmark
| | - Peter Bie
- Department of Cardiovascular and Renal Research, University of Southern Denmark, Odense, Denmark
| | - Tobias Wang
- Zoophysiology, Department of Biological Sciences, Aarhus University, Aarhus C, Denmark
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White CR, Kearney MR. Metabolic scaling in animals: methods, empirical results, and theoretical explanations. Compr Physiol 2014; 4:231-56. [PMID: 24692144 DOI: 10.1002/cphy.c110049] [Citation(s) in RCA: 117] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Life on earth spans a size range of around 21 orders of magnitude across species and can span a range of more than 6 orders of magnitude within species of animal. The effect of size on physiology is, therefore, enormous and is typically expressed by how physiological phenomena scale with mass(b). When b ≠ 1 a trait does not vary in direct proportion to mass and is said to scale allometrically. The study of allometric scaling goes back to at least the time of Galileo Galilei, and published scaling relationships are now available for hundreds of traits. Here, the methods of scaling analysis are reviewed, using examples for a range of traits with an emphasis on those related to metabolism in animals. Where necessary, new relationships have been generated from published data using modern phylogenetically informed techniques. During recent decades one of the most controversial scaling relationships has been that between metabolic rate and body mass and a number of explanations have been proposed for the scaling of this trait. Examples of these mechanistic explanations for metabolic scaling are reviewed, and suggestions made for comparing between them. Finally, the conceptual links between metabolic scaling and ecological patterns are examined, emphasizing the distinction between (1) the hypothesis that size- and temperature-dependent variation among species and individuals in metabolic rate influences ecological processes at levels of organization from individuals to the biosphere and (2) mechanistic explanations for metabolic rate that may explain the size- and temperature-dependence of this trait.
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Affiliation(s)
- Craig R White
- School of Biological Sciences, The University of Queensland, St Lucia, Queensland, Australia
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30
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Olesen ND, van Lieshout JJ, Fisher JP, Seifert T, Nielsen HB, Secher NH. Case report: (Pre)syncopal symptoms associated with a negative internal jugular venous pressure. Front Physiol 2014; 5:317. [PMID: 25191276 PMCID: PMC4139713 DOI: 10.3389/fphys.2014.00317] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2014] [Accepted: 08/03/2014] [Indexed: 11/13/2022] Open
Abstract
A siphon is suggested to support cerebral blood flow but appears not to be established because internal jugular venous (IJV) pressure is close to zero in upright humans. Thus, in eleven young healthy males, IJV pressure was 9 ± 1 mmHg (mean ± SE) when supine and fell to 3 ± 1 mmHg when seated, and middle cerebral artery mean blood velocity (MCA Vmean; P < 0.007) and the near-infrared spectroscopy-determined frontal lobe oxygenation (ScO2; P = 0.028) also decreased. Another subject, however, developed (pre)syncopal symptoms while seated and his IJV pressure decreased to −17 mmHg. Furthermore, his MCA Vmean decreased and yet within the time of observation ScO2 was not necessarily affected. These findings support the hypothesis that a negative IJV pressure that is a prerequisite for creation of a siphon provokes venous collapse inside the dura, and thereby limits rather than supports CBF.
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Affiliation(s)
- Niels D Olesen
- Department of Anesthesia, Rigshospitalet, University of Copenhagen Copenhagen, Denmark
| | - Johannes J van Lieshout
- Department of Internal Medicine, Academic Medical Centre, University of Amsterdam Amsterdam, Netherlands ; Laboratory for Clinical Cardiovascular Physiology, Centre for Heart Failure Research, Academic Medical Centre Amsterdam, Netherlands ; MRC/Arthritis Research UK Centre for Musculoskeletal Ageing Research, School of Life Sciences, The Medical School, University of Nottingham, Queen's Medical Centre Nottingham, UK
| | - James P Fisher
- School of Sport, Exercise & Rehabilitation Sciences, College of Life and Environmental Sciences University of Birmingham, UK
| | - Thomas Seifert
- Department of Anesthesia, Rigshospitalet, University of Copenhagen Copenhagen, Denmark
| | - Henning B Nielsen
- Department of Anesthesia, Rigshospitalet, University of Copenhagen Copenhagen, Denmark
| | - Niels H Secher
- Department of Anesthesia, Rigshospitalet, University of Copenhagen Copenhagen, Denmark
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Petersen LG, Carlsen JF, Nielsen MB, Damgaard M, Secher NH. The hydrostatic pressure indifference point underestimates orthostatic redistribution of blood in humans. J Appl Physiol (1985) 2014; 116:730-5. [PMID: 24481962 DOI: 10.1152/japplphysiol.01175.2013] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The hydrostatic indifference point (HIP; where venous pressure is unaffected by posture) is located at the level of the diaphragm and is believed to indicate the orthostatic redistribution of blood, but it remains unknown whether HIP coincides with the indifference point for blood volume (VIP). During graded (± 20°) head-up (HUT) and head-down tilt (HDT) in 12 male volunteers, we determined HIP from central venous pressure and VIP from redistribution of both blood, using ultrasound imaging of the inferior caval vein (VIPui), and fluid volume, by regional electrical admittance (VIPadm). Furthermore, we evaluated whether inflation of medical antishock trousers (to 70 mmHg) affected HIP and VIP. Leaving cardiovascular variables unaffected by tilt, HIP was located 7 ± 4 cm (mean ± SD) below the 4th intercostal space (IC-4) during HUT and was similar (7 ± 3 cm) during HDT and higher (P < 0.0001) than both VIPui (HUT: 22 ± 16 cm; HDT: 13 ± 7 cm) and VIPadm (HUT: 29 ± 9 cm; HDT: 20 ± 9 cm below IC-4). During HUT antishock trousers elevated both HIP and VIPui [to 3 ± 5 cm (P = 0.028) and 17 ± 7 cm below IC-4 (P = 0.051), respectively], while VIPadm remained unaffected. By simultaneous recording of pressure and filling of the inferior caval vein as well as fluid distribution, we found HIP located corresponding to the diaphragm while VIP was placed low in the abdomen, and that medical antishock trousers elevated both HIP and VIP. The low indifference point for volume shows that the gravitational influence on distribution of blood is more profound than indicated by the indifference point for venous pressure.
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Affiliation(s)
- L G Petersen
- Department of Biomedical Sciences, The Panum Institute, University of Copenhagen, Copenhagen, Denmark
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Regnault N, Kleinman KP, Rifas-Shiman SL, Langenberg C, Lipshultz SE, Gillman MW. Components of height and blood pressure in childhood. Int J Epidemiol 2014; 43:149-59. [PMID: 24413933 DOI: 10.1093/ije/dyt248] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
BACKGROUND In children being taller is associated with higher blood pressure (BP), but few studies have divided height into its components: trunk and leg length. We examined the associations of total height, trunk length and leg length with systolic BP (SBP), diastolic BP (DBP) and pulse pressure (PP) at early childhood and mid-childhood visits, as well as change between the two visits. METHODS We obtained five measures of SBP and DBP at the early childhood visit (N = 1153, follow-up rate = 54%) and at the mid-childhood visit (N = 1086, follow-up rate = 51%) respectively, in Project Viva, a US cohort study. We measured total height and sitting height (a measure of trunk length that includes head and neck) and calculated leg length as the difference between the two. Using mixed models, we adjusted the cross-sectional analyses for leg length when trunk length was the exposure of interest, and vice versa. We also adjusted for maternal race/ethnicity, child age, sex, overall adiposity and BP measurement conditions. RESULTS At the mid-childhood visit, total height was positively associated with SBP [0.34 (0.24; 0.45) mmHg/cm] but not with DBP [0.07 (-0.003; 0.15)]. In models examining trunk and leg length separately, each was positively associated with SBP [0.72 (0.52; 0.92) and 0.33 (0.16; 0.49) respectively]. In a fully adjusted model with both leg and trunk length, only trunk length remained associated with BP. For a given leg length, a 1-cm increment in trunk length was associated with a 0.63-mmHg (0.42; 0.83) higher SBP and a 0.17-mmHg (0.02; 0.31) higher DBP. For a given trunk length, however, the associations of leg length with SBP [0.13 (-0.03; 0.30)] and with DBP [0.002 (-0.11; 0.12)] were null. These patterns were similar at the early childhood visit. CONCLUSIONS Children with greater trunk lengths have higher BPs, perhaps because of the additional pressure needed to overcome gravity to perfuse the brain.
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Affiliation(s)
- Nolwenn Regnault
- Obesity Prevention Program, Department of Population Medicine, Harvard Medical School and Harvard Pilgrim Health Care Institute, Boston, MA, USA, MRC Epidemiology Unit, Addenbrooke's Hospital, University of Cambridge, Cambridge, UK, Department of Pediatrics, University of Miami Miller School of Medicine, Miami, FL, USA and Department of Nutrition, Harvard School of Public Health, Boston, MA, USA
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Petersen KK, Hørlyck A, Østergaard KH, Andresen J, Broegger T, Skovgaard N, Telinius N, Laher I, Bertelsen MF, Grøndahl C, Smerup M, Secher NH, Brøndum E, Hasenkam JM, Wang T, Baandrup U, Aalkjaer C. Protection against high intravascular pressure in giraffe legs. Am J Physiol Regul Integr Comp Physiol 2013; 305:R1021-30. [DOI: 10.1152/ajpregu.00025.2013] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The high blood pressure in giraffe leg arteries renders giraffes vulnerable to edema. We investigated in 11 giraffes whether large and small arteries in the legs and the tight fascia protect leg capillaries. Ultrasound imaging of foreleg arteries in anesthetized giraffes and ex vivo examination revealed abrupt thickening of the arterial wall and a reduction of its internal diameter just below the elbow. At and distal to this narrowing, the artery constricted spontaneously and in response to norepinephrine and intravascular pressure recordings revealed a dynamic, viscous pressure drop along the artery. Histology of the isolated median artery confirmed dense sympathetic innervation at the narrowing. Structure and contractility of small arteries from muscular beds in the leg and neck were compared. The arteries from the legs demonstrated an increased media thickness-to-lumen diameter ratio, increased media volume, and increased numbers of smooth muscle cells per segment length and furthermore, they contracted more strongly than arteries from the neck (500 ± 49 vs. 318 ± 43 mmHg; n = 6 legs and neck, respectively). Finally, the transient increase in interstitial fluid pressure following injection of saline was 5.5 ± 1.7 times larger ( n = 8) in the leg than in the neck. We conclude that 1) tissue compliance in the legs is low; 2) large arteries of the legs function as resistance arteries; and 3) structural adaptation of small muscle arteries allows them to develop an extraordinary tension. All three findings can contribute to protection of the capillaries in giraffe legs from a high arterial pressure.
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Affiliation(s)
- Karin K. Petersen
- Department of Radiology, Aarhus University Hospital, Skejby, Denmark
| | - Arne Hørlyck
- Department of Radiology, Aarhus University Hospital, Skejby, Denmark
| | - Kristine H. Østergaard
- Zoophysiology, Department of Bioscience, Aarhus University, Aarhus, Denmark
- Department of Pathology, Vendsyssel Hospital and Center for Clinical Research, Aalborg University, Denmark
| | | | | | - Nini Skovgaard
- Zoophysiology, Department of Bioscience, Aarhus University, Aarhus, Denmark
| | - Niklas Telinius
- Department of Biomedicine, Aarhus University, Aarhus, Denmark
| | - Ismael Laher
- Department of Pharmacology and Therapeutics, University of British Columbia, Vancouver, British Columbia, Canada
| | - Mads F. Bertelsen
- Center for Zoo and Wild Animal Health, Copenhagen Zoo, Frederiksberg, Denmark
| | - Carsten Grøndahl
- Center for Zoo and Wild Animal Health, Copenhagen Zoo, Frederiksberg, Denmark
| | - Morten Smerup
- Department of CardioThoracic and Vascular Surgery and Institute of Clinical Medicine, Aarhus University Hospital, Skejby, Denmark; and
| | - Niels H. Secher
- Department of Anesthesiology, and The Copenhagen Muscle Research Center, Rigshopitalet, University of Copenhagen, Denmark
| | - Emil Brøndum
- Department of Biomedicine, Aarhus University, Aarhus, Denmark
| | - John M. Hasenkam
- Department of CardioThoracic and Vascular Surgery and Institute of Clinical Medicine, Aarhus University Hospital, Skejby, Denmark; and
| | - Tobias Wang
- Zoophysiology, Department of Bioscience, Aarhus University, Aarhus, Denmark
| | - Ulrik Baandrup
- Department of Pathology, Vendsyssel Hospital and Center for Clinical Research, Aalborg University, Denmark
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Rondeau DA, Mackalonis ME, Hess RS. Effect of body position on indirect measurement of systolic arterial blood pressure in dogs. J Am Vet Med Assoc 2013; 242:1523-7. [DOI: 10.2460/javma.242.11.1523] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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Arvedsen SK, Damgaard M, Norsk P. Body height and blood pressure regulation in humans during anti-orthostatic tilting. Am J Physiol Regul Integr Comp Physiol 2012; 302:R984-9. [DOI: 10.1152/ajpregu.00036.2011] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The hypothesis was tested that the cardiovascular changes during an upper body anti-orthostatic maneuver in humans are more pronounced in tall than in short individuals, because of the larger intravascular hydrostatic pressure gradients. In 34 males and 41 females [20–30 yr, body height (BH) = 147–206 cm], inter-individual multiple linear regression analyses adjusted for gender and body weight were conducted between changes in cardiovascular variables versus BH during tilting of the upper body from vertical to horizontal while keeping the legs horizontal. In all the subjects, tilting induced increases in stroke volume and arterial pulse pressure and a decrease in heart rate, which each correlated significantly with BH. In males ( n = 51, BH = 163–206 cm), 24-h ambulatory mean arterial pressure increased significantly with BH ( P = 0.004, r = 0.40, α = 0.15 mmHg/cm) so that systolic/diastolic blood pressure increased by 2/2 mmHg per 15 cm increase in BH. There was no significant correlation between mean arterial pressure and BH in females ( n = 53, BH = 147–193 cm). In conclusion, a larger BH induces larger cardiovascular changes during anti-orthostatic tilting, and in males 24-h ambulatory mean arterial pressure increases with BH. The lack of a mean arterial pressure to BH correlation in females is probably because of their lower BH and greater variability in blood pressure.
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Affiliation(s)
- Sine K. Arvedsen
- Department of Biomedical Sciences, Faculty of Health Sciences, University of Copenhagen, Copenhagen
| | - Morten Damgaard
- Department of Clinical Physiology and Nuclear Medicine, Hvidovre University Hospital, Hvidovre, Denmark
| | - Peter Norsk
- Department of Biomedical Sciences, Faculty of Health Sciences, University of Copenhagen, Copenhagen
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Greene NH, Lee LA. Modern and Evolving Understanding of Cerebral Perfusion and Autoregulation. Adv Anesth 2012; 30:97-129. [PMID: 28275288 DOI: 10.1016/j.aan.2012.08.003] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Affiliation(s)
- Nathaniel H Greene
- Department of Anesthesiology and Pain Medicine, University of Washington, Seattle, WA 98195-6540, USA
| | - Lorri A Lee
- Department of Anesthesiology and Pain Medicine, University of Washington, Seattle, WA 98195-6540, USA; Department of Neurological Surgery, University of Washington, Seattle, WA 98195-6540, USA
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Østergaard KH, Bertelsen MF, Brøndum ET, Aalkjær C, Hasenkam JM, Smerup M, Wang T, Nyengaard JR, Baandrup U. Pressure profile and morphology of the arteries along the giraffe limb. J Comp Physiol B 2011; 181:691-8. [DOI: 10.1007/s00360-010-0545-z] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2010] [Revised: 12/07/2010] [Accepted: 12/09/2010] [Indexed: 10/18/2022]
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A definition of normovolaemia and consequences for cardiovascular control during orthostatic and environmental stress. Eur J Appl Physiol 2010; 109:141-57. [PMID: 20052592 PMCID: PMC2861179 DOI: 10.1007/s00421-009-1346-5] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/22/2009] [Indexed: 11/20/2022]
Abstract
The Frank–Starling mechanism describes the relationship between stroke volume and preload to the heart, or the volume of blood that is available to the heart—the central blood volume. Understanding the role of the central blood volume for cardiovascular control has been complicated by the fact that a given central blood volume may be associated with markedly different central vascular pressures. The central blood volume varies with posture and, consequently, stroke volume and cardiac output (\documentclass[12pt]{minimal}
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\begin{document}$$ \dot{Q} $$\end{document}) are affected, but with the increased central blood volume during head-down tilt, stroke volume and \documentclass[12pt]{minimal}
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\begin{document}$$ \dot{Q} $$\end{document} do not increase further indicating that in the supine resting position the heart operates on the plateau of the Frank–Starling curve which, therefore, may be taken as a functional definition of normovolaemia. Since the capacity of the vascular system surpasses the blood volume, orthostatic and environmental stress including bed rest/microgravity, exercise and training, thermal loading, illness, and trauma/haemorrhage is likely to restrict venous return and \documentclass[12pt]{minimal}
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\begin{document}$$ \dot{Q} $$\end{document}. Consequently the cardiovascular responses are determined primarily by their effect on the central blood volume. Thus during environmental stress, flow redistribution becomes dependent on sympathetic activation affecting not only skin and splanchnic blood flow, but also flow to skeletal muscles and the brain. This review addresses the hypothesis that deviations from normovolaemia significantly influence these cardiovascular responses.
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