Vaughan M K, Trakulrungsi C, Petterborg L J, Johnson L Y, Blask D E, Trakulrungsi W, Reiter R J
Mol Cell Endocrinol. 1979 Apr;14(1):59-71. doi: 10.1016/0303-7207(79)90058-3.
Treatment of unanesthetized castrated adult male rats every 3 h for 48 h with either 5 microgram of arginine vasotocin (AVT) and/or 1 microgram luteinizing hormone-releasing hormone (LRH) caused a significant inhibition of plasma levels of luteinizing hormone (LH) and compared to castrated control rats receiving diluent only. However, the intravenous (iv) injection of 1 microgram of AVT into urethane-anesthetized male rats which had been castrated for 0, 24 or 48 h did not affect plasma levels of LH at 10, 20 or 60 min following injection compared to their respective diluent-treated castrated control rats. Similarly, the iv injection of either 100 ng, 1 microgram or 10 microgram AVT was unable to acutely affect plasma levels of LH in intact male rats. Following the iv injection of 2 doses of 50 ng LRH spaced 1 h apart in anesthetized castrated male rats, 2 peaks of equal magnitude in plasma LH were noted. Castrated rats treated with 2 injections spaced 1 h apart of LRH + AVT had significantly higher plasma levels of LH than did rats treated with LRH alone. In subsequent studies, both AVT and arginine vasopressin were observed to augment the plasma response of LH to an injection of LRH whereas oxytocin had no effect. A single injection of AVT + LRH significantly augmented the plasma titers of LH compared to levels observed in LRH-treated control rats as did a second injection 1 h later. The administration of cyproterone acetate sc for 2 days by itself had no effect on plasma LH but in conjunction with LRH caused a marked rise in plasma LH compared to intact rats treated with LRH alone. AVT in combination with LRH and cyproterone acetate caused a significant elevation in plasma LH at 60 min post-injection when compared to plasma levels of rats treated with LRH alone or the combination of LRH and cyproterone acetate. It is concluded that acute intravenous injections of AVT augment the LH-releasing activity of LRH; chronic treatment for 48 h, however, with LRH + AVT leads to a significant depression of plasma LH perhaps due to an exhaustion of the releasable pool of LH in the anterior pituitary.
每隔3小时给未麻醉的成年去势雄性大鼠注射5微克精氨酸加压催产素（AVT）和/或1微克促黄体生成素释放激素（LRH），持续48小时，与仅接受稀释剂的去势对照大鼠相比，可显著抑制促黄体生成素（LH）的血浆水平。然而，给已去势0、24或48小时的氨基甲酸乙酯麻醉的雄性大鼠静脉注射（iv）1微克AVT，与各自接受稀释剂处理的去势对照大鼠相比，注射后10、20或60分钟时LH的血浆水平未受影响。同样，静脉注射100纳克、1微克或10微克AVT均无法急性影响完整雄性大鼠LH的血浆水平。在麻醉的去势雄性大鼠中，静脉注射2剂间隔1小时的50纳克LRH后，血浆LH出现两个大小相等的峰值。间隔1小时注射2次LRH + AVT的去势大鼠，其血浆LH水平显著高于仅接受LRH治疗的大鼠。在随后的研究中，观察到AVT和精氨酸加压素均可增强LH对注射LRH的血浆反应，而催产素则无此作用。与LRH治疗的对照大鼠相比，单次注射AVT + LRH可显著提高LH的血浆滴度，1小时后第二次注射亦是如此。皮下注射醋酸环丙孕酮2天，其本身对血浆LH无影响，但与LRH联合使用时，与仅接受LRH治疗的完整大鼠相比，可导致血浆LH显著升高。与仅接受LRH治疗或LRH与醋酸环丙孕酮联合治疗的大鼠血浆水平相比，注射后60分钟时，AVT与LRH和醋酸环丙孕酮联合使用可使血浆LH显著升高。得出的结论是，急性静脉注射AVT可增强LRH释放LH的活性；然而，用LRH + AVT进行48小时的慢性治疗会导致血浆LH显著降低，这可能是由于垂体前叶中可释放的LH储备耗尽所致。
