Forsling M L, Judah J M, Windle R J
Department of Gynaecology, UMDS, London, UK.
J Endocrinol. 1994 Apr;141(1):59-67. doi: 10.1677/joe.0.1410059.
Urine flow, sodium excretion, mean arterial blood pressure and glomerular filtration rate (GFR) were determined in the conscious unrestrained rat infused with hypotonic saline. The effects of vasopressin infused at 24 and 160 pmol/min and oxytocin infused at 30 and 200 pmol/min were determined. The lower doses of each hormone gave plasma concentrations within the physiological range whereas the higher doses produced plasma concentrations equivalent to those seen following dehydration. Vasopressin produced dose-dependent antidiuretic and natriuretic responses. Hormone infused at both rates increased the clearance of sodium, but only the higher dose caused a significant increase in GFR. Fractional excretion of sodium was significantly elevated by both doses. Oxytocin produced dose-dependent diuretic and natriuretic responses. Again both rates of infusion increased the clearance of sodium, but only the higher dose caused a significant increase in GFR. The lower dose caused a significant increase in the fractional excretion of sodium. It appears, therefore, that increases in GFR may have a role in the natriuretic response to both hormones. However, this response can also be seen when GFR remains unchanged. This fact, together with the observed increases in the fractional excretion of sodium, indicates that these hormones have additional tubular actions.
在给清醒自由活动的大鼠输注低渗盐水的情况下，测定了其尿流量、钠排泄量、平均动脉血压和肾小球滤过率（GFR）。测定了以24和160 pmol/分钟输注血管加压素以及以30和200 pmol/分钟输注催产素的效果。每种激素的较低剂量使血浆浓度处于生理范围内，而较高剂量产生的血浆浓度与脱水后所见的浓度相当。血管加压素产生剂量依赖性的抗利尿和利钠反应。以两种速率输注的激素均增加了钠的清除率，但只有较高剂量导致GFR显著增加。两种剂量均使钠的分数排泄显著升高。催产素产生剂量依赖性的利尿和利钠反应。同样，两种输注速率均增加了钠的清除率，但只有较高剂量导致GFR显著增加。较低剂量使钠的分数排泄显著增加。因此，似乎GFR的增加可能在对两种激素的利钠反应中起作用。然而，当GFR保持不变时也能看到这种反应。这一事实，连同观察到的钠分数排泄增加，表明这些激素具有额外的肾小管作用。
