Noradrenergic control of central oxytocin release during lactation in rats
Noradrenergic control of central oxytocin release during lactation in rats
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DOI：
10.1152/ajpendo.1998.274.3.e453
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发表时间：
1998-03-01
影响因子：
5.1
通讯作者：
Crowley, WR
中科院分区：
文献类型：
--
作者：
Bealer, SL;Crowley, WR
去甲肾上腺素能系统调节哺乳期大鼠全身催产素(OT)的释放。然而，在哺乳过程中，去甲肾上腺素(NE)在巨细胞核内释放催产素的作用尚未确定。这些研究旨在确定1)哺乳是否诱导清醒大鼠视上核(SON)和室旁核(PVN)中去甲肾上腺素(NE)的释放；2)去甲肾上腺素(NE)在这些核团内中枢催产素(OT)释放中的作用。雌性Holtzman大鼠在哺乳期第8-12天在PVN或SON附近植入微透析探头。第二天，用人工脑脊液(ACSF)或含有α-或β-肾上腺素能受体拮抗剂的ACSF灌流微透析探头。在哺乳前、中、后收集透析液，分析NE或OT。在另一项实验中，通过微透析探头将α或β肾上腺素能激动剂注射到非哺乳期大鼠的PVN中。在哺乳过程中，室旁核细胞外去甲肾上腺素升高，但在产后未检测到胞外去甲肾上腺素。在哺乳过程中，PVN和SON的透析液中OT浓度显著升高。阻断α-肾上腺素能受体(PVN和SON)或β-肾上腺素能受体(PVN)可阻止哺乳引起的中枢OT释放的增加。中枢应用α-或β-肾上腺素能激动剂可增加非哺乳、哺乳期大鼠的OT释放。这些数据表明，哺乳增加了下丘脑室旁核内去甲肾上腺素的释放，随后对α和β去甲肾上腺素受体的刺激介导了核内去甲肾上腺素的释放。
Noradrenergic systems regulate the systemic release of oxytocin (OT) in lactating rats. However, a role for norepinephrine (NE) in release of OT within the magnocellular nuclei during suckling has not been established. These studies were designed to determine 1) if suckling induces NE release in the supraoptic (SON) and paraventricular (PVN) nuclei of conscious rats and 2) the role of NE in the central, intranuclear release of OT within these nuclei. Female Holtzman rats were implanted with microdialysis probes adjacent to the PVN or SON on lactation days 8-12. The following day, the pups were isolated from the dams for 4 h. Microdialysis probes were perfused with artificial cerebrospinal fluid (ACSF) or with ACSF containing an alpha- or a beta-adrenergic receptor antagonist. Dialysate was collected before, during, and after suckling and analyzed for NE or OT. In an additional experiment, an alpha- or beta-adrenergic agonist was administered via the microdialysis probes into the PVN in nonsuckled, lactating rats. Extracellular NE increased in the PVN during suckling but was not detectable in the SON. OT concentrations in dialysates from the PVN and SON significantly increased during suckling. Blockade of either alpha- (in both PVN and SON) or beta-(PVN) adrenergic receptors prevented the suckling-induced increase in central OT release. OT release was increased in nonsuckled, lactating rats by central application of either an alpha- or beta-adrenergic agonist. These data demonstrate that intranuclear NE release is increased in the PVN by suckling and that subsequent stimulation of both alpha- and beta-noradrenergic receptors mediates intranuclear OT release.