Babini R, du Souich P
Department of Pharmacology, Faculty of Medicine, University of Montréal, Québec, Canada.
Res Commun Chem Pathol Pharmacol. 1993 May;80(2):131-41.
The aim of this study was to assess the role of arginine-vasopressin (AVP) on extracellular water distribution (VE) and on the urinary excretion of sodium in conscious rabbits with or without water deprivation. The study included two groups of animals. The first group involved two subgroups, both receiving an infusion of 0.9% NaCl-5% glucose (50-50, v:v) at the rate of 24 ml/hr to adequately hydrate the rabbits, but one received 2.5 ng/min/kg of AVP with the infusion; 120 min later, a bolus of inulin was injected to assess the distribution in the extracellular water. The rabbits of the second group were divided into 3 subgroups, receiving a 0.9% NaCl-5% glucose (50-50, v:v) infusion, at the rate of 6 ml/min; two subgroups received AVP, at the rate of 2.5 or 5 ng/min/kg; 40 minutes later, all animals received a bolus of inulin. In adequately hydrated rabbits, the infusion of AVP generated plasma levels of 35 +/- 7 pg/ml; the VE decreased from 204 +/- 23 to 111 +/- 10 ml/kg (p < 0.01) because of a decrease in plasma (VP) and interstitial volumes (VI). In the same group, natriuresis and osmolal clearance increased and free water clearance decreased. In rabbits deficiently hydrated, AVP reached plasma levels of 47 +/- 18 and 86 +/- 12 pg/ml following the 2.5 and 5 ng/min/kg infusions, respectively. In these animals, high plasma levels of AVP did not diminish VE but decreased the diuresis and osmolal clearance. It is concluded that in adequately hydrated rabbits, pathophysiological plasma levels of AVP shift the water from the VE to the intracellular space and increase the natriuresis, but in partially hydrated rabbits, the infusion of AVP maintains plasma volume constant because of an antidiuretic effect.
本研究的目的是评估精氨酸加压素（AVP）在有水剥夺或无水剥夺的清醒兔中对细胞外液分布（VE）和尿钠排泄的作用。该研究包括两组动物。第一组包括两个亚组，两组均以24 ml/hr的速率输注0.9% NaCl-5%葡萄糖（50-50，v:v）以使兔充分水化，但其中一组在输注时接受2.5 ng/min/kg的AVP；120分钟后，注射一剂菊粉以评估其在细胞外液中的分布。第二组兔分为3个亚组，以6 ml/min的速率接受0.9% NaCl-5%葡萄糖（50-50，v:v）输注；两个亚组分别以2.5或5 ng/min/kg的速率接受AVP；40分钟后，所有动物均接受一剂菊粉。在充分水化的兔中，输注AVP使血浆水平达到35±7 pg/ml；由于血浆（VP）和间质容积（VI）减少，VE从204±23降至111±10 ml/kg（p<0.01）。在同一组中，利钠作用和渗透清除率增加，自由水清除率降低。在水化不足的兔中，分别以2.5和5 ng/min/kg输注AVP后，AVP的血浆水平分别达到47±18和86±12 pg/ml。在这些动物中，高血浆水平的AVP并未减少VE，但减少了利尿作用和渗透清除率。得出的结论是，在充分水化的兔中，病理生理血浆水平的AVP使水从VE转移至细胞内空间并增加利钠作用，但在部分水化的兔中，输注AVP由于抗利尿作用而维持血浆容积恒定。
