Parrott R F, Thornton S N, Baldwin B A, Forsling M L
Institute of Animal Physiology and Genetics Research, Agricultural and Food Research Council, Babraham, Cambridge, United Kingdom.
Am J Physiol. 1988 Aug;255(2 Pt 2):R248-51. doi: 10.1152/ajpregu.1988.255.2.R248.
Two studies were carried out to examine endocrine changes during a 60-min period of operant drinking in 24-h dehydrated pigs. Measurements were made of water intake, osmolality, hematocrit, and plasma concentrations of lysine vasopressin (LVP) and cortisol during rehydration (experiment 1) and of fluid intake, osmolality, and LVP levels during consumption of isotonic saline (experiment 2). Increases in osmolality and LVP produced by dehydration in experiment 1 were rapidly reversed during rehydration with the result that osmolality returned to predeprivation levels after 20 min and LVP after 30 min, but there was no evidence of a decrease in LVP before absorption. Plasma cortisol concentrations were unaffected by dehydration although they declined during the final 40 min of experiment 1. In experiment 2, osmolality remained elevated during saline drinking, but plasma concentrations of LVP declined abruptly. The results suggest that oropharyngeal factors inhibiting vasopressin release, revealed during saline ingestion, are obscured during normal rehydration as a result of the rapid rate at which water is absorbed by the gut in this species.
进行了两项研究，以检查24小时脱水猪在60分钟操作性饮水期间的内分泌变化。在补液期间（实验1）测量了水摄入量、渗透压、血细胞比容以及赖氨酸加压素（LVP）和皮质醇的血浆浓度，在饮用等渗盐水期间（实验2）测量了液体摄入量、渗透压和LVP水平。实验1中脱水引起的渗透压和LVP升高在补液过程中迅速逆转，结果是渗透压在20分钟后恢复到剥夺前水平，LVP在30分钟后恢复，但没有证据表明吸收前LVP会降低。血浆皮质醇浓度不受脱水影响，尽管在实验1的最后40分钟内有所下降。在实验2中，饮用盐水期间渗透压仍然升高，但血浆LVP浓度突然下降。结果表明，在饮用盐水期间显示出的抑制加压素释放的口咽因素，在正常补液过程中被该物种肠道快速吸收水分的速度所掩盖。
