荷包牡丹碱对垂体前叶组织块释放促肾上腺皮质激素的刺激效应

BICUCULLINE STIMULATES THE RELEASE OF ADRENOCORTICOTROPIN (ACTH)FROM RAT ANTERIOR PITUITARY QUARTERS

本实验利用垂体组织块离体灌流技术，观察到－氨基丁酸Ａ受体拮抗剂荷包牡丹碱对切除双侧肾上腺９６ｈ后的大鼠垂体前叶ＡＣＴＨ的分泌具有强烈的刺激作用。但同样浓度的荷包牡丹碱对分离的垂体前叶细胞的ＡＣＴＨ分泌无影响。提示肾上腺切除后，－氨基丁酸在垂体前叶直接或通过间接途径抑制ＡＣＴＨ分泌。

The effect of gama aminobutyric acid (GABA) on release of adrenocorticotropin (ACTH) from anterior pituitary quarters of male SD rats adrenalectomized for 96 hrs was investigated using the perfusion technique in vitro. Application of bicuculline (10 -6 mol/L),a specific GABA A antagonist,resulted in a significant release of ACTH from perfused anterior pituitary quarters.But the same concentration of bicuculline had no effect on the release of ACTH from dispersed anterior cells of ADX rats in vitro.Taken together,these results suggest that GABA may play an important inhibitory role on ACTH secretion from pituitary in adrenalectomized rats.