【摘要】 本工作分在体和离体两部分实验。(1)给清醒自由活动的大鼠第三脑室内微量注射0.5和2.0μg的胰多肽(PP),观察到PP显著抑制前叶垂体β-内啡肽(β-EP)和催乳素(PRL)的静息分泌,抑制效应随PP的剂量增加而增大。此外,0.5μgPP能部分抑制限制性应激引起的PRL的释放;2.0μgPP只部分抑制此应激引起的β-EP的释放,并显著抑制应激时PRL的释放。(2)离体实验于体外培养的前叶垂体细胞中,分别加入0.05,0.625.1.00μgPP,一起孵育1h,看到0.625和1.00μg的PP显著抑制PTL的释放,抑制效应依PP的剂量增加而增大;上述三种剂量的PP对前叶垂体细胞β-EP的分泌均无影响。这些结果提示,PP可能通过某种下丘脑机制抑制前叶垂体β-EP和PRL的释放,也可直接作用于前叶垂体细胞抑制PRL的释放。更多还原

【Abstract】 This study was designed to examine the possible effects of pancreatic polypeptide(PP) on β-endorphin (β-EP) and prolactin (PRL) release from rat anterior pituitary inrivo and in ritro. Injection of 0.5 μg or 2.0 μg PP into the third ventricle of the brain(3rd v. i.) produced a significant decrease of the β-EP and PRL resting secretion. 0.5μg PP (3rd v. i.) did not affect restraint stress--induced release of β-EP, but partiallylowered stress induced release of PRL. 2.0 μg PP (3rd v. i.) partially reduced re-straint stress--induced release of β-EP and completely suppressed stress--induced releaseof PRL. In order to investigate a possible direct action of PP on β-EP and PRL secre-tion from the anterior pituitary gland. we incubated dispersed anterior pituitary cellswith synthetic PP (0.05, 0.625 and 1.00 μg) for 1 n, the secretion of β--EP was notaffected at any dosage tested, but 0.625 and 1.00 μg PP significantly decreased thePRL secretion. These data indicate that PP may have an inhibitory role in the controlof β--EP secretion at the level of the hypothalamus, and an inhibitory role in the controlof PRL secretion at the level of either hypothalamus or anterior pituitary.更多还原