Navarra P, Eechaute W, Preziosi P, Lacroix E
Laboratory of Normal and Pathological Physiology, State University of Ghent, Belgium.
Horm Metab Res. 1991 May;23(5):213-7. doi: 10.1055/s-2007-1003656.
It has recently been shown that the specific and selective alpha 2-antagonist idazoxan (IDZ) displays prolactin-lowering activity on hyperprolactinemia induced in the rat either by suckling or serotonergic drugs. In an attempt better to understand the role of alpha 2-adrenoceptors under the above conditions, experiments were carried out to compare the effects of IDZ with that of the classic alpha 2-antagonist yohimbine (YOH), and also of the alpha 2-agonists clonidine (CLO) and B-HT 920, on prolactin (PRL) release during lactation and in hyperprolactinemia induced in male rats by the serotonergic drug fenfluramine (FEN). In lactating rats, both alpha 2-agonists decreased PRL release; this effect was enhanced by prior separation of the animals from their pups for several hours. A decrease of plasma PRL levels was also induced by IDZ but not by YOH, which tended further to increase hyperprolactinemia. In male rats treated with FEN, IDZ and CLO, a significant decrease of plasma PRL was produced, but YOH further enhanced PRL secretion. It is concluded that the alpha 2-agonists tested and also the alpha 2-antagonist IDZ display a unique inhibitory activity on PRL release during suckling or serotonergic-induced hyperprolactinemia.
最近有研究表明，特异性和选择性α2拮抗剂咪唑克生（IDZ）对大鼠因哺乳或血清素能药物诱导的高催乳素血症具有降低催乳素的活性。为了更好地理解α2肾上腺素能受体在上述条件下的作用，进行了实验，比较IDZ与经典α2拮抗剂育亨宾（YOH）以及α2激动剂可乐定（CLO）和B-HT 920对哺乳期和血清素能药物芬氟拉明（FEN）诱导的雄性大鼠高催乳素血症期间催乳素（PRL）释放的影响。在哺乳期大鼠中，两种α2激动剂均降低PRL释放；若事先将动物与其幼崽分离数小时，这种作用会增强。IDZ可降低血浆PRL水平，但YOH不能，YOH反而倾向于进一步加重高催乳素血症。在用FEN处理的雄性大鼠中，IDZ和CLO可使血浆PRL显著降低，但YOH会进一步增强PRL分泌。结论是，所测试的α2激动剂以及α2拮抗剂IDZ在哺乳或血清素能诱导的高催乳素血症期间对PRL释放均表现出独特的抑制活性。
