Petraglia F, Locatelli V, Penalva A, Cella S G, Genazzani A R, Cocchi D
Life Sci. 1984 Apr 16;34(16):1605-11. doi: 10.1016/0024-3205(84)90616-7.
The existence of independent control mechanisms of beta-endorphin (beta-EP) secretion from the anterior (AP) and intermediate (NIL) pituitary lobes is now ascertained. The aim of this study was to evaluate the effect of surgical separation from the hypothalamus of the two pituitary lobes on beta-EP secretion. Two experimental models of surgical hypothalamo-pituitary disconnection were used: 1) rats with ablation of the medial basal hypothalamus (MBH); 2) rats bearing two entire ectopic pituitaries or two anterior pituitaries (APs) only, transplanted under the kidney capsule. In rats with MBH-ablation plasma beta-EP levels were significantly higher than in sham-operated controls. Plasma beta-EP levels increased in rats transplanted with entire pituitaries 3 days after surgery and were still elevated after 1 week. In rats transplanted with APs only, no significant beta-EP changes in plasma were evident. In both experimental conditions no significant difference was present in beta-LPH plasma levels. Concentrations of beta-EP in the ectopic NILs decreased gradually after transplantation. In all these results indicate that that NIL but not the AP is capable, when is disconnected from the hypothalamus, or secreting autonomously beta-EP.
现已确定垂体前叶（AP）和垂体中间叶（NIL）存在β-内啡肽（β-EP）分泌的独立调控机制。本研究的目的是评估将垂体的两个叶与下丘脑手术分离对β-EP分泌的影响。采用了两种手术性下丘脑-垂体切断的实验模型：1）内侧基底下丘脑（MBH）切除的大鼠；2）仅在肾被膜下移植两个完整的异位垂体或两个垂体前叶（AP）的大鼠。在MBH切除的大鼠中，血浆β-EP水平显著高于假手术对照组。移植完整垂体的大鼠术后3天血浆β-EP水平升高，1周后仍升高。仅移植AP的大鼠，血浆中β-EP无明显变化。在两种实验条件下，血浆β-LPH水平均无显著差异。移植后异位NIL中β-EP的浓度逐渐降低。所有这些结果表明，当与下丘脑分离时，NIL而非AP能够自主分泌β-EP。
