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Andreev-Andrievskiy A, Popova A, Lloret JC, Aubry P, Borovik A, Tsvirkun D, Vinogradova O, Ilyin E, Gauquelin-Koch G, Gharib C, Custaud MA. BION-M 1: First continuous blood pressure monitoring in mice during a 30-day spaceflight. LIFE SCIENCES IN SPACE RESEARCH 2017; 13:19-26. [PMID: 28554506 DOI: 10.1016/j.lssr.2017.03.002] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/21/2016] [Accepted: 03/19/2017] [Indexed: 06/07/2023]
Abstract
Animals are an essential component of space exploration and have been used to demonstrate that weightlessness does not disrupt essential physiological functions. They can also contribute to space research as models of weightlessness-induced changes in humans. Animal research was an integral component of the 30-day automated Russian biosatellite Bion-M 1 space mission. The aim of the hemodynamic experiment was to estimate cardiovascular function in mice, a species roughly 3000 times smaller than humans, during prolonged spaceflight and post-flight recovery, particularly, to investigate if mice display signs of cardiovascular deconditioning. For the first time, heart rate (HR) and blood pressure (BP) were continuously monitored using implantable telemetry during spaceflight and recovery. Decreased HR and unchanged BP were observed during launch, whereas both HR and BP dropped dramatically during descent. During spaceflight, BP did not change from pre-flight values. However, HR increased, particularly during periods of activity. HR remained elevated after spaceflight and was accompanied by increased levels of exercise-induced tachycardia. Loss of three of the five mice during the flight as a result of the hardware malfunction (unrelated to the telemetry system) and thus the limited sample number constitute the major limitation of the study. For the first time BP and HR were continuously monitored in mice during the 30-day spaceflight and 7-days of post-flight recovery. Cardiovascular deconditioning in these tiny quadruped mammals was reminiscent of that in humans. Therefore, the loss of hydrostatic pressure in space, which is thought to be the initiating event for human cardiovascular adaptation in microgravity, might be of less importance than other physiological mechanisms. Further experiments with larger number of mice are needed to confirm these findings.
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Affiliation(s)
- Alexander Andreev-Andrievskiy
- SSC RF Institute for Biomedical Problems RAS, 76A Khoroshevskoe sh., 123007, Moscow, Russia; Lomonosov Moscow State University, Biology Faculty, 1-12, Leninskie Gory, 119234, Moscow, Russia.
| | - Anfisa Popova
- SSC RF Institute for Biomedical Problems RAS, 76A Khoroshevskoe sh., 123007, Moscow, Russia; Lomonosov Moscow State University, Biology Faculty, 1-12, Leninskie Gory, 119234, Moscow, Russia
| | | | - Patrick Aubry
- CNES, French Space Agency, 8 av Edouard Belin, 31401, Toulouse, France
| | - Anatoliy Borovik
- SSC RF Institute for Biomedical Problems RAS, 76A Khoroshevskoe sh., 123007, Moscow, Russia
| | - Daria Tsvirkun
- Laboratory of Integrated Neurovascular and Mitochondrial Biology (BNMI), UMR CNRS 6214, INSERM 1083, Faculté de Médecine d'Angers, 49045 Angers, France; CaDyWEC International Laboratory, Angers University, Angers, France
| | - Olga Vinogradova
- SSC RF Institute for Biomedical Problems RAS, 76A Khoroshevskoe sh., 123007, Moscow, Russia
| | - Eugeniy Ilyin
- SSC RF Institute for Biomedical Problems RAS, 76A Khoroshevskoe sh., 123007, Moscow, Russia
| | | | - Claude Gharib
- Laboratory of Physiology, Medical School Lyon Est, 8, Avenue Rockfeller, 69373, Lyon, France
| | - Marc-Antoine Custaud
- Laboratory of Integrated Neurovascular and Mitochondrial Biology (BNMI), UMR CNRS 6214, INSERM 1083, Faculté de Médecine d'Angers, 49045 Angers, France; CaDyWEC International Laboratory, Angers University, Angers, France.
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Zeredo ZL, Toda K, Kumei Y. Neuronal Activity in the Subthalamic Cerebrovasodilator Area under Partial-Gravity Conditions in Rats. Life (Basel) 2014; 4:107-16. [PMID: 25370031 PMCID: PMC4187145 DOI: 10.3390/life4010107] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2014] [Revised: 02/18/2014] [Accepted: 02/26/2014] [Indexed: 01/23/2023] Open
Abstract
The reduced-gravity environment in space is known to cause an upward shift in body fluids and thus require cardiovascular adaptations in astronauts. In this study, we recorded in rats the neuronal activity in the subthalamic cerebrovasodilator area (SVA), a key area that controls cerebral blood flow (CBF), in response to partial gravity. “Partial gravity” is the term that defines the reduced-gravity levels between 1 g (the unit gravity acceleration on Earth) and 0 g (complete weightlessness in space). Neuronal activity was recorded telemetrically through chronically implanted microelectrodes in freely moving rats. Graded levels of partial gravity from 0.4 g to 0.01 g were generated by customized parabolic-flight maneuvers. Electrophysiological signals in each partial-gravity phase were compared to those of the preceding 1 g level-flight. As a result, SVA neuronal activity was significantly inhibited by the partial-gravity levels of 0.15 g and lower, but not by 0.2 g and higher. Gravity levels between 0.2–0.15 g could represent a critical threshold for the inhibition of neurons in the rat SVA. The lunar gravity (0.16 g) might thus trigger neurogenic mechanisms of CBF control. This is the first study to examine brain electrophysiology with partial gravity as an experimental parameter.
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Affiliation(s)
- Zeredo L Zeredo
- Graduate School, Tokyo Medical and Dental University, Tokyo 113-8549, Japan.
| | - Kazuo Toda
- Graduate School, Nagasaki University, 1-7-1 Sakamoto, Nagasaki 852-8588, Japan.
| | - Yasuhiro Kumei
- Graduate School, Tokyo Medical and Dental University, Tokyo 113-8549, Japan.
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Okumura S, Tsunematsu T, Bai Y, Jiao Q, Ono S, Suzuki S, Kurotani R, Sato M, Minamisawa S, Umemura S, Ishikawa Y. Type 5 adenylyl cyclase plays a major role in stabilizing heart rate in response to microgravity induced by parabolic flight. J Appl Physiol (1985) 2008; 105:173-9. [PMID: 18450980 DOI: 10.1152/japplphysiol.01166.2007] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
It is well known that autonomic nervous activity is altered under microgravity, leading to disturbed regulation of cardiac function, such as heart rate. Autonomic regulation of the heart is mostly determined by beta-adrenergic receptors/cAMP signal, which is produced by adenylyl cyclase, in cardiac myocytes. To examine a hypothesis that a major cardiac isoform, type 5 adenylyl cyclase (AC5), plays an important role in regulating heart rate during parabolic flights, we used transgenic mouse models with either disrupted (AC5KO) or overexpressed AC5 in the heart (AC5TG) and analyzed heart rate variability. Heart rate had a tendency to decrease gradually in later phases within one parabola in each genotype group, but the magnitude of decrease was smaller in AC5KO than that in the other groups. The inverse of heart rate, i.e., the R-R interval, was much more variable in AC5KO and less variable in AC5TG than that in wild-type controls. The standard deviation of normal R-R intervals, a marker of total autonomic variability, was significantly greater in microgravity phase in each genotype group, but the magnitude of increase was much greater in AC5KO than that in the other groups, suggesting that heart rate regulation became unstable in the absence of AC5. In all, AC5 plays a major role in stabilizing heat rate under microgravity.
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Affiliation(s)
- Satoshi Okumura
- Cardiovascular Research Institute, Yokohama City University Graduate School of Medicine, 3-9 Fukuura, Kanazawa-ku, Yokohama 236-0004, Japan
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Morita H, Abe C, Awazu C, Tanaka K. Long-term hypergravity induces plastic alterations in vestibulo-cardiovascular reflex in conscious rats. Neurosci Lett 2006; 412:201-5. [PMID: 17123714 DOI: 10.1016/j.neulet.2006.11.014] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2006] [Revised: 10/25/2006] [Accepted: 11/03/2006] [Indexed: 11/25/2022]
Abstract
To test the hypothesis that an altered gravitational environment induces plastic changes in the vestibulo-cardiovascular reflex, arterial pressure (AP) and hypothalamic glutamate concentration were examined in 2 groups of conscious rats, i.e., a 3-G group and a 1-G group, in which rats were maintained under a 3-G and 1-G environment for 2 weeks, respectively. The vestibulo-cardiovascular reflex was stimulated by a gravitational change induced by a parabolic flight that consisted of 3 phases: "pull-up", during which the G load gradually increased to 2G; a 20s "push-over" into microgravity; and "pull-out", during which the G load increased to 1.8. In the 1-G group, the AP increased by 11.9+/-1.2 mmHg during the pull-up hypergravity period. The AP response was significantly attenuated in the 3-G group (4.0+/-0.8 mmHg). During the push-over microgravity period, the AP decreased from the peak level in the pull-up period and recovered to the pre-parabolic control level (-1.8+/-2.4 mmHg). In rats of the 3-G group, the AP was not altered by push-over microgravity. These AP responses were associated with a significant increase in the glutamate concentration in the hypothalamus (4.4+/-0.7%). The glutamate response was also significantly attenuated in the 3-G group compared with that in the 1-G group. These results indicate that an altered gravitational environment induces plastic alterations in the vestibulo-cardiovascular reflex.
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Affiliation(s)
- Hironobu Morita
- Department of Physiology, Gifu University Graduate School of Medicine, 1-1 Yanagido, Gifu 501-1194, Japan.
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Tanaka K, Gotoh TM, Awazu C, Morita H. Regional difference of blood flow in anesthetized rats during reduced gravity induced by parabolic flight. J Appl Physiol (1985) 2005; 99:2144-8. [PMID: 16081624 DOI: 10.1152/japplphysiol.00336.2005] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
To examine a hypothesis that change in regional blood flow due to decreased hydrostatic pressure gradient and redistribution of blood during reduced gravity (rG) is different between organs, changes in cerebrocortical blood flow (CBF) and blood flow in the temporal muscle (MBF) with exposure to rG were measured in anesthetized rats in head-up tilt and flat positions during parabolic flight. Carotid arterial pressure (CAP), jugular venous pressure (JVP), and abdominal aortic pressure were also measured simultaneously. In the head-up tilt group, CBF increased by 15 +/- 3% within 3 s of entry into rG and rapidly recovered during rG. MBF also increased, but the change was significantly greater than that of CBF. JVP increased by 1.8 +/- 0.5 mmHg, probably due to loss of hydrostatic pressure gradient, since the measuring point of JVP was 2-3 cm above the hydrostatic indifference point. CAP and abdominal aortic pressure increased by 16.7 +/- 2 and 7.7 +/- 2 mmHg, respectively, compared with the 1-G condition. Muscle vascular resistance [(CAP-JVP)/MBF] decreased on entry into rG, but no significant change was observed in cerebrocortical vascular resistance [(CAP-JVP)/CBF]. In the flat group, no significant change was observed in all the variables. The results indicate that arteriolar vasodilatation occurs in the temporal muscle but not in the cerebral cortex. Thus the blood flow control mechanism at the onset of rG is different between intra- and extracranial organs.
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Affiliation(s)
- Kunihiko Tanaka
- Dept. of Physiology, Gifu University, Graduate School of Medicine, Gifu, Japan.
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Gotoh TM, Fujiki N, Matsuda T, Gao S, Morita H. Roles of baroreflex and vestibulosympathetic reflex in controlling arterial blood pressure during gravitational stress in conscious rats. Am J Physiol Regul Integr Comp Physiol 2003; 286:R25-30. [PMID: 14500268 DOI: 10.1152/ajpregu.00458.2003] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Gravity acts on the circulatory system to decrease arterial blood pressure (AP) by causing blood redistribution and reduced venous return. To evaluate roles of the baroreflex and vestibulosympathetic reflex (VSR) in maintaining AP during gravitational stress, we measured AP, heart rate (HR), and renal sympathetic nerve activity (RSNA) in four groups of conscious rats, which were either intact or had vestibular lesions (VL), sinoaortic denervation (SAD), or VL plus SAD (VL + SAD). The rats were exposed to 3 G in dorsoventral axis by centrifugation for 3 min. In rats in which neither reflex was functional (VL + SAD group), RSNA did not change, but the AP showed a significant decrease (-8 +/- 1 mmHg vs. baseline). In rats with a functional baroreflex, but no VSR (VL group), the AP did not change and there was a slight increase in RSNA (25 +/- 10% vs. baseline). In rats with a functional VSR, but no baroreflex (SAD group), marked increases in both AP and RSNA were observed (AP 31 +/- 6 mmHg and RSNA 87 +/- 10% vs. baseline), showing that the VSR causes an increase in AP in response to gravitational stress; these marked increases were significantly attenuated by the baroreflex in the intact group (AP 9 +/- 2 mmHg and RSNA 38 +/- 7% vs. baseline). In conclusion, AP is controlled by the combination of the baroreflex and VSR. The VSR elicits a huge pressor response during gravitational stress, preventing hypotension due to blood redistribution. In intact rats, this AP increase is compensated by the baroreflex, resulting in only a slight increase in AP.
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Affiliation(s)
- Taro Miyahara Gotoh
- Department of Physiology, Gifu University School of Medicine, 40 Tsukasa-Machi, Gifu 500-8705, Japan.
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