| タイトル | Increased beta-adrenergic responsiveness induced by 14 days exposure to simulated microgravity |
| 著者（英） | Polet, J. L.; Engelke, K. A.; Blomqvist, C. G.; Hoffler, G. W.; Lane, L. D.; Convertino, V. A. |
| 著者所属（英） | NASA Kennedy Space Center |
| 発行日 | 1995-01-01
1995 |
| 言語 | eng |
| 内容記述 | Increased sensitivity of end-organ responses to neuroendocrine stimuli as a result of prolonged exposure to the relative inactivity of microgravity has recently been hypothesized. This notion is based on the inverse relationship between circulating norepinephrine and beta-adrenoreceptor sensitivity. The beta-adrenoreceptor activity is reduced in individuals who have elevated plasma norepinephrine as a result of regular exposure to upright posture and physical exercise. In contrast, adrenoreceptor hypersensitivity has been reported in patients with dysautonomias in which circulating catecholamines are absent or reduced. Taken together, these studies and the observation that circulating plasma norepinephrine has been reduced during spaceflight and in groundbased simulations of microgravity prompt the suggestion that adrenoreceptor hypersensitivity may be a consequence of the adaptation to spaceflight. We conducted an experiment designed to measure cardiovascular responses to adrenoreceptor agonists in human subjects before and after prolonged exposure to 6 deg head-down tilt (HDT) to test the hypothesis that adaptation to microgravity increases adrenoreceptor responsiveness, and that this adaptation is associated with reduced levels of circulating norepinephrine. |
| NASA分類 | Aerospace Medicine |
| レポートNO | 96N24976 |
| 権利 | No Copyright |
| URI | https://repository.exst.jaxa.jp/dspace/handle/a-is/542934 |
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