D. Eatman, R.A. Listhrop, A.S. Beasley, R.R. Socci, I. Abukhalaf, M.A. Bayorh
{"title":"Influences of prostanoids and nitric oxide on post-suspension hypotension in female Sprague–Dawley rats","authors":"D. Eatman, R.A. Listhrop, A.S. Beasley, R.R. Socci, I. Abukhalaf, M.A. Bayorh","doi":"10.1016/S0952-3278(02)00270-3","DOIUrl":null,"url":null,"abstract":"<div><div><span><span>Impairment in cardiovascular functions sometimes manifested in astronauts during standing postflight, may be related to the diminished autonomic function and/or excessive production of endothelium-dependent relaxing factors. In the present study, using the 30° head-down tilt (HDT) model, we compared the cardiovascular and biochemical effects of 7 days of suspension and a subsequent 6-h post-suspension period between suspended and non-suspended conscious female Sprague–Dawley rats. </span>Mean arterial pressure (MAP) and heart rate were measured prior to suspension (basal), daily thereafter, and every 2</span> <span>h post-suspension. Following 7 days of suspension, MAP was not different from their basal values, however, upon release from suspension, MAP was significantly reduced compared to the non-suspended rats. Nitric oxide levels were elevated while thromboxane A</span><sub>2</sub><span> levels declined significantly in both plasma and tissue samples following post-suspension. The levels of prostacyclin<span> following post-suspension remained unaltered in plasma and aortic rings but was significantly elevated in carotid arterial rings. Therefore, the post-suspension reduction in mean arterial pressure is due mostly to overproduction of nitric oxide and to a lesser extent prostacyclin.</span></span></div></div>","PeriodicalId":94179,"journal":{"name":"Prostaglandins, leukotrienes, and essential fatty acids","volume":"68 3","pages":"Pages 197-205"},"PeriodicalIF":3.0000,"publicationDate":"2003-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Prostaglandins, leukotrienes, and essential fatty acids","FirstCategoryId":"1085","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0952327802002703","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}
引用次数: 0
Abstract
Impairment in cardiovascular functions sometimes manifested in astronauts during standing postflight, may be related to the diminished autonomic function and/or excessive production of endothelium-dependent relaxing factors. In the present study, using the 30° head-down tilt (HDT) model, we compared the cardiovascular and biochemical effects of 7 days of suspension and a subsequent 6-h post-suspension period between suspended and non-suspended conscious female Sprague–Dawley rats. Mean arterial pressure (MAP) and heart rate were measured prior to suspension (basal), daily thereafter, and every 2h post-suspension. Following 7 days of suspension, MAP was not different from their basal values, however, upon release from suspension, MAP was significantly reduced compared to the non-suspended rats. Nitric oxide levels were elevated while thromboxane A2 levels declined significantly in both plasma and tissue samples following post-suspension. The levels of prostacyclin following post-suspension remained unaltered in plasma and aortic rings but was significantly elevated in carotid arterial rings. Therefore, the post-suspension reduction in mean arterial pressure is due mostly to overproduction of nitric oxide and to a lesser extent prostacyclin.