Prolactin alters luteinizing hormone pulsation characteristics in the intact and castrate male rabbit.
Prolactin alters luteinizing hormone pulsation characteristics in the intact and castrate male rabbit.
复制标题
催乳素改变完整和去势雄性兔子的黄体生成素脉动特征。
作者：
J. Larsen;W. Odell
研究了催乳素 (PRL) 对完整和去势雄性兔子的黄体生成素 (LH) 脉动特征的影响。研究了八组动物。两组去势兔子和两组成年雄性兔子作为对照，以建立基线脉动特征。初步研究表明，3-4 分钟的采样间隔是最佳的。以该频率对一组去势兔和一组未完整兔进行采样，持续 60 分钟；对另外两组进行了 240 分钟的采样。确定这些数据后，将四组用于配对研究：两组去势组和两组完整组接受静脉推注盐水或 PRL（20 微克），然后持续输注盐水或 PRL（50 微克/分钟）3.5 小时。在输注的最后 1.5 小时内，每 3 分钟采集一次血液样本。测量每个样本的血清 LH；对合并样本进行兔 PRL 测量。在选定的样品中还测量了牛 PRL。 3 组去势组和完整对照组（未灌注和生理盐水灌注）的 LH 脉动特征没有统计学差异，并且汇总了数据。将 PRL 治疗的动物与对照组进行比较。去势增加了 LH 平均浓度、脉冲幅度和持续时间。 PRL输注降低了完整动物和去势动物的平均LH浓度和脉搏幅度。通过PRL输注，去势动物的脉冲持续时间显着缩短，但完整动物的脉冲持续时间没有显着缩短。我们的结论是，在成年雄性兔子中，PRL 调节 LH 脉动。 PRL 的这种作用必须直接发生在垂体，或更可能是通过影响下丘脑促性腺激素释放激素的脉动而发生。
The effect of prolactin (PRL) on luteinizing hormone (LH) pulsation characteristics in intact and castrate male rabbits was investigated. Eight groups of animals were studied. Two groups castrate and two groups of adult male rabbits served as controls to establish baseline pulsation characteristics. Preliminary studies showed that a sampling interval of 3-4 min was optimal. One group of castrate and one group of intact rabbits were sampled at this frequency for 60 min; two additional groups were sampled for 240 min. With these data determined, four groups were used in paired studies: two castrate and two intact groups received either a bolus injection intravenously of saline or PRL (20 micrograms), followed by a constant infusion of saline or PRL (50 micrograms/min) for 3.5 h. Blood was sampled every 3 min for the last 1.5 h of infusion. Serum LH was measured on each sample; rabbit PRL was measured on pooled samples. In selected samples bovine PRL was also measured. The LH pulsation characteristics of the 3 groups of castrate and intact controls (unperfused and saline-perfused) were not statistically different and the data were pooled. The PRL-treated animals were compared to the controls. Castration increased LH mean concentration, pulse amplitude and duration. PRL infusion decreased mean LH concentration and pulse amplitude in both intact and castrate animals. Pulse duration was decreased significantly in castrate, but not in intact, animals by PRL infusion. We conclude that, in the adult male rabbit, PRL modulates LH pulsation. This action of PRL must occur either directly at the pituitary or more probably through an influence on gonadotropin-releasing hormone pulsation at the hypothalamus.