Windle R J, Forsling M L
Department of Obstetrics and Gynaecology, United Medical and Dental Schools, London, UK.
J Endocrinol. 1997 Aug;154(2):347-53. doi: 10.1677/joe.0.1540347.
Oxytocin was administered to virgin female rats at doses of 25-200 pmol/min during 0.077 mol NaCl/l infusion at 150 microliters/min on each day of the oestrous cycle. The resultant rates of urine flow, glomerular filtration (GFR) and electrolyte excretion were determined. Oxytocin caused significant increases in urine flow (P < 0.001) and sodium excretion (P < 0.001); both responses being dose-dependent (P < 0.02 and P < 0.01 respectively). Significant variations in the renal responsiveness to the hormone occurred over the 4 days of the oestrous cycle. On oestrus the lowest dose of 25 pmol oxytocin/min produced a significant increase in urine flow (from 139.5 +/- 4.3 to 165.6 +/- 7.1 microliters/min, P < 0.005) and a dose of 50 pmol/min produced a significant increase in sodium excretion (from 10.6 +/- 0.1 to 14.5 +/- 0.7 mumol/min, P < 0.005). Significant increases in urine flow and sodium excretion were seen on pro-oestrus with hormone administration rates of 50 and 100 pmol/min respectively and on dioestrus day 2 with a rate of 100 pmol/min. On dioestrus day 1 no increase in urine flow or sodium excretion was seen over the dose range of oxytocin administration. A dose of 100 pmol oxytocin/min significantly increased GFR on pro-oestrus and dioestrus day 2, but not on the other 2 days of the cycle. The circulating hormone concentrations produced by oxytocin infusion were similar on each day of the cycle and so could not account for the differences seen. Therefore, these results suggest varying renal responsiveness to oxytocin during the reproductive cycle of the female rat.
在发情周期的每一天，以150微升/分钟的速度输注0.077摩尔/升的氯化钠溶液时，向未交配的雌性大鼠注射催产素，剂量为25 - 200皮摩尔/分钟。测定由此产生的尿流率、肾小球滤过率（GFR）和电解质排泄率。催产素可使尿流率（P < 0.001）和钠排泄量显著增加（P < 0.001）；两种反应均呈剂量依赖性（分别为P < 0.02和P < 0.01）。在发情周期的4天里，肾脏对该激素的反应性出现显著变化。在发情期，最低剂量25皮摩尔/分钟的催产素可使尿流率显著增加（从139.5 ± 4.3微升/分钟增至165.6 ± 7.1微升/分钟，P < 0.005），50皮摩尔/分钟的剂量可使钠排泄量显著增加（从10.6 ± 0.1微摩尔/分钟增至14.5 ± 0.7微摩尔/分钟，P < 0.005）。在发情前期，分别以50和100皮摩尔/分钟的激素给药速率可使尿流率和钠排泄量显著增加，在间情期第2天，以100皮摩尔/分钟的速率给药也有同样效果。在间情期第1天，在催产素给药剂量范围内，未观察到尿流率或钠排泄量增加。100皮摩尔/分钟的催产素剂量在发情前期和间情期第2天可使GFR显著增加，但在周期的其他两天则无此作用。在周期的每一天，通过输注催产素产生的循环激素浓度相似，因此无法解释所观察到的差异。所以，这些结果表明雌性大鼠生殖周期中肾脏对催产素的反应性存在差异。
