Immunoneutralization of endogenous opioid peptides prevents the suckling-induced prolactin increase and the inhibition of tuberoinfundibular dopaminergic neurons
Immunoneutralization of endogenous opioid peptides prevents the suckling-induced prolactin increase and the inhibition of tuberoinfundibular dopaminergic neurons
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DOI：
10.1159/000054545
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发表时间：
2000-04-01
影响因子：
4.1
通讯作者：
Janik, J
中科院分区：
文献类型：
--
作者：
Callahan, P;Klosterman, S;Janik, J
以往的研究表明，内源性阿片肽，作用于特定的阿片受体亚型，参与了吸吮诱导的催乳素分泌反应。催乳素增加引起的吸吮，至少部分是由于抑制下丘脑的结节漏斗多巴胺（TIDA）神经元，我们研究了免疫中和的强啡肽，亮脑啡肽和甲硫氨酸脑啡肽对哺乳诱导的催乳素增加和哺乳期雌性大鼠产后7天和12天之间的TIDA神经元的活性的影响。将对这三种肽中的一种具有特异性的抗血清注射到大鼠的右侧脑室中，向对照大鼠施用等量的免疫球蛋白。哺乳产生了深刻的和显着的催乳素水平的增加，以及减少多巴积累在正中隆起的哺乳大鼠。免疫球蛋白浓度高达3.6 μ g的管理没有抑制催乳素分泌反应的吸吮刺激，并没有阻止吸吮诱导的抑制TIDA神经元。所有三种内源性阿片肽的抗血清消除了吸吮诱导的催乳素增加，并阻止了多巴蓄积在正中隆起的抑制。因此，内源性阿片肽，强啡肽，亮脑啡肽和甲啡肽，是必不可少的催乳素分泌反应，吸吮和TIDA神经元活性的抑制是至少一个由这些肽利用的作用机制。版权所有（C）2000 S. Karger AG，巴塞尔。
Previous studies have shown that the endogenous opioid peptides, acting at specific opiate receptor subtypes, are involved in the suckling-induced prolactin secretory response. The prolactin increase elicited by suckling is due, at least in part, to an inhibition of tuberoinfundibular dopaminergic (TIDA) neurons in the hypothalamus, We investigated the effects of immunoneutralization of dynorphin, leu-enkephalin and met-enkephalin on the suckling-induced prolactin increase and on the activity of the TIDA neurons in lactating female rats between days 7 and 12 postpartum. Rats were injected into the right lateral ventricle with antiserum specific for one of these three peptides, Control rats were administered equal amounts of immunoglobulin proteins. Suckling produced a profound and significant increase in prolactin levels, as well as a decrease in DOPA accumulation in the median eminence of lactating rats. Administration of immunoglobulin concentrations of up to 3.6 mu g did not inhibit the prolactin secretory response to the suckling stimulus and did not prevent the suckling-induced inhibition of TIDA neurons. Antisera to all three endogenous opioid peptides abolished the suckling-induced prolactin increase and prevented the inhibition in DOPA accumulation in the median eminence. Thus, the endogenous opioid peptides, dynorphin, leu-enkephalin and metenkephalin, are essential for the prolactin secretory response to suckling and inhibition of TIDA neuronal activity is at least one of the mechanisms of action utilized by these peptides. Copyright (C) 2000 S. Karger AG, Basel.