Ashton N, Balment R J
Department of Physiological Sciences, University of Manchester, UK.
Acta Endocrinol (Copenh). 1988 Jul;118(3):422-8. doi: 10.1530/acta.0.1180422.
The acute effects of physiological levels of AVP and oxytocin administration on renal water and sodium handling have been investigated in New Zealand genetically hypertensive and normotensive rats. AVP infusion was associated with an antidiuresis in both normotensive and hypertensive rats and while normotensive rats also displayed a dose-related natriuresis, this was attenuated in hypertensive rats. Oxytocin administration had no effect on urine flow or sodium excretion in normotensive rats, but was associated with an antidiuresis in hypertensive rats. Combined hormone infusion produced a greater reduction in urine flow than following AVP alone in both normotensive and hypertensive groups and was associated with a potentiation of the natriuretic action of AVP in the hypertensive animals. The data suggest that the contribution of oxytocin to renal sodium excretion in hypertensive rats may be suppressed. A compensatory increase in basal AVP secretion in hypertensive rats may overcome their apparent renal insensitivity to AVP, to maintain appropriate sodium excretion. This intriguing disturbance in neurohypophysial function may reflect or possibly contribute to the hypertension of these animals.
在新西兰遗传性高血压大鼠和正常血压大鼠中，研究了生理水平的抗利尿激素（AVP）和催产素给药对肾脏水和钠处理的急性影响。在正常血压和高血压大鼠中，输注AVP均与抗利尿作用相关，虽然正常血压大鼠也表现出与剂量相关的利钠作用，但在高血压大鼠中这种作用减弱。给予催产素对正常血压大鼠的尿流或钠排泄没有影响，但在高血压大鼠中与抗利尿作用相关。在正常血压和高血压组中，联合输注激素比单独输注AVP产生更大的尿流减少，并且在高血压动物中与AVP利钠作用的增强相关。数据表明，催产素对高血压大鼠肾钠排泄的贡献可能受到抑制。高血压大鼠基础AVP分泌的代偿性增加可能克服其对AVP明显的肾脏不敏感性，以维持适当的钠排泄。神经垂体功能的这种有趣紊乱可能反映或可能导致这些动物的高血压。
