Park R G, Congiu M, Denton D A, McKinley M J
Am J Physiol. 1985 Dec;249(6 Pt 2):F799-805. doi: 10.1152/ajprenal.1985.249.6.F799.
The aim of this study was to investigate whether arginine vasopressin (AVP) is natriuretic in sheep at plasma concentrations comparable to those induced by water deprivation. AVP was infused intravenously at 0.1, 0.2, and 0.5 microgram/h for 24-48 h in sheep allowed free access to water. Infusion of AVP at 0.1 microgram/h did not alter renal Na output, whereas infusion of AVP at both 0.2 and 0.5 microgram/h significantly increased daily output of Na in urine. Significant natriuresis did not occur until 3.5 h after the start of AVP infusion at 0.2 microgram/h. Plasma AVP levels induced by these infusions were 9.8 +/- 1.6 (0.1 microgram/h AVP), 21.9 +/- 7.7 (0.2 microgram/h AVP), and 32.5 +/- 9.0 pg/ml (0.5 microgram/h AVP) after 24 h. These concentrations are within the range found in sheep deprived of water for 3 days. Hypophysectomy abolished increases in plasma AVP concentration but not natriuresis in response to water deprivation. This suggests that increased plasma AVP concentration does not play an essential role in the mechanisms subserving dehydration-induced natriuresis.
本研究的目的是探讨在绵羊体内，精氨酸加压素（AVP）在与禁水诱导的血浆浓度相当的情况下是否具有利钠作用。在自由饮水的绵羊中，以0.1、0.2和0.5微克/小时的速率静脉输注AVP，持续24 - 48小时。以0.1微克/小时的速率输注AVP不会改变肾脏钠排泄量，而以0.2和0.5微克/小时的速率输注AVP则显著增加了尿钠的日排泄量。以0.2微克/小时的速率开始输注AVP 3.5小时后才出现显著的利钠作用。输注24小时后，这些输注诱导的血浆AVP水平分别为9.8±1.6（0.1微克/小时AVP）、21.9±7.7（0.2微克/小时AVP）和32.5±9.0皮克/毫升（0.5微克/小时AVP）。这些浓度处于禁水3天的绵羊体内所发现的范围内。垂体切除消除了血浆AVP浓度的升高，但并未消除禁水引起的利钠作用。这表明血浆AVP浓度升高在脱水诱导的利钠机制中并不起关键作用。
