Seckl J R, Williams T D, Lightman S L
Am J Physiol. 1986 Aug;251(2 Pt 2):R214-7. doi: 10.1152/ajpregu.1986.251.2.R214.
After dehydration, oral rehydration causes a fall in plasma arginine vasopressin (AVP) that precedes changes in plasma osmolality. To investigate further the stimulus for this effect, its specificity, and association with thirst, six volunteers were deprived of water for 24 h and given a salt load on two separate occasions. On each study day they then drank rapidly 10 ml/kg of either tap water or hypertonic saline (360 mosmol/kg). There was a significant fall in plasma AVP from 2.0 +/- 0.3 to 1.2 +/- 0.4 pmol/l (P less than 0.05) 5 min after drinking water and from 1.8 +/- 0.3 to 0.9 +/- 0.2 pmol/l (P less than 0.05) after hypertonic saline. Plasma osmolality fell 30-60 min after water and was unchanged after saline. Plasma renin activity, oxytocin, and total protein all remained unchanged. All subjects reported diminished thirst after hypertonic saline. Gargling with water reduced thirst but did not affect plasma AVP. There appears to be a drinking-mediated neuroendocrine reflex that decreases plasma AVP irrespective of the osmolality of the liquid consumed. The sensation of thirst did not correlate with plasma osmolality and was not always related to plasma AVP concentration.
脱水后，口服补液会导致血浆精氨酸加压素（AVP）下降，且这一变化先于血浆渗透压的改变。为进一步研究这种效应的刺激因素、其特异性以及与口渴的关系，六名志愿者被禁水24小时，并在两个不同的时间段给予盐负荷。在每个研究日，他们随后迅速饮用10 ml/kg的自来水或高渗盐水（360 mosmol/kg）。饮水后5分钟，血浆AVP从2.0±0.3降至1.2±0.4 pmol/l（P<0.05），饮用高渗盐水后从1.8±0.3降至0.9±0.2 pmol/l（P<0.05）。饮水后30 - 60分钟血浆渗透压下降，饮用盐水后则无变化。血浆肾素活性、催产素和总蛋白均保持不变。所有受试者在饮用高渗盐水后均表示口渴减轻。用水漱口可减轻口渴，但不影响血浆AVP。似乎存在一种由饮水介导的神经内分泌反射，无论所摄入液体的渗透压如何，都会降低血浆AVP。口渴感与血浆渗透压无关，也并非总是与血浆AVP浓度相关。
