雌性大鼠离体垂体前叶内在促黄体生成激素释放节律性现象

众所周知，下丘脑促性腺激素释放激素以脉冲形式驱使垂体前叶释放促黄体生成激素，但垂体前叶本身彼和ＬＨ的形式却遭忽略。直到Ｍａｒｃｏ Ｇａｍｂａｃｃｉａｎｉ和谢二发现人和大鼠离体垂体的ＬＨ释放呈节律性。本文目的在于进一步证实是否确定存在ＬＨ释放的内在节律。

PHENOMENON OF INTRINSIC RHYTHM OF LUTEINIZING HORMONE RELEASE FROM ISOLATED ANTERIOR PITUITARY GLAND OF FEMALE RAT

The intrinsic nature of rthymic release of luteinizing hormone (LH) of isolated human and rat anterior pituitare gland reported independently by Macro Gambacciani and Xie in 1987 can be more directly demonstrated by a computer programme of Time Series-HSY Hidden Periodic Analytic Approach for continuous monitoring the LH output of the perfusate from a perfusion system with in vitro anterior pituitary of SD female rat. The results are as follows: (1) Under various reproductive conditions the average frequency (min/cycle) and amplitude (ng/ml) of the intrinsic rhythm of LH release were quite different: In proestrous group the frequency and amplitude were the highest, being intermediate in the ovariectomized group and lowest in the lactation group. (2) The intrinsic rhythm of LH release could be changed by either peptide or steriod hormones. In proestrous group with 30 min of gonadotropin-releasing hormone (GnRH), stimulation would reduce both frequency and amplitude. In case of lactation, the frequency was unchanged, but amplitude lowered, while in the ovariectomized rat pituitap, the 30 min GnRH stimulation decreased the frequency of release only. The intrinsic rhythm of the LH release could also be influenced by steriod hormones (Ru486 and Anordrin). With 120 min before removal of the anterior pituitary gland the rats receiving i. m. injection ofRu486 (2 mg/kg bw) or Anordrin (2 mg/kg), the results showed that Ru486 decreased frequency, while Anordrin decreased only the frenquency to a less extent, both without amplitude affected. (3) Verapamil and EGTA added to the perfusion system did not abolish but only decreased the rhythmic phenomenon by using proestrous pituteq. This suggests that participation of Ca2 may take place in the intrinsic release of LH.The above results indicated that the intrinsic rhythm of LH release of isolated anterior pituitary gland is different from various reproductive hormonal conditions and capable of being modified by exogenous hormones. The physiological function of the intrinsic rhythm of LH release of anterior pituitare gland remains to be elucidated.