Pinilla L, González L C, Tena-Sempere M, Aguilar E
Department of Physiology, Faculty of Medicine, Córdoba University, Spain.
J Physiol Biochem. 2001 Sep;57(3):237-44. doi: 10.1007/BF03179817.
Prolactin secretion is controlled by the hypothalamus through different neurotransmitters which interact with multiple receptor subtypes. The discovery of different families of receptors for serotonin (5-HT1-5-HT7) and excitatory aminoacids (NMDA, KA, AMPA and metabotropic receptors) ilustrates the complexity of this regulation. Moreover, in the rat the role of different neurotransmitters changes during pubertal development. Present experiments were carried out to analyse the interactions between AMPA and serotoninergic receptors in the control of prolactin secretion in prepubertal male rats. For this purpose, 16 and 23-day old male rats were treated with 5-hydroxytryptophan (5-HTP, precursor of serotonin synthesis) plus fluoxetine (blocker of serotonin reuptake), 8-OH-DPAT (agonist of 5-HT1A receptors), DOI and alpha-Me-5-HT (agonists of 5-HT2 receptors), 1-phenylbiguanide (agonist of 5-HT3 receptors) alone or in combination with AMPA (agonist of AMPA receptors). The results obtained indicate that: (a) activation of 5-HT1A receptors stimulated PRL secretion on day 16 and inhibited it on day 23; activation of 5-HT2 receptors stimulated PRL secretion on days 16 and 23, whereas activation of 5-HT3 receptors inhibited PRL release only on day 23; (b) activation of AMPA receptors inhibited PRL secretion on day 23, but not on day 16 and (c) a cross-talk is apparent between 5-HT2 and AMPA receptors in the regulation of PRL secretion, the stimulatory effect of DOI being blocked by AMPA.
催乳素的分泌受下丘脑通过不同神经递质的控制，这些神经递质与多种受体亚型相互作用。血清素（5-HT1 - 5-HT7）和兴奋性氨基酸（NMDA、KA、AMPA和代谢型受体）不同受体家族的发现说明了这种调节的复杂性。此外，在大鼠中，不同神经递质的作用在青春期发育过程中会发生变化。本实验旨在分析AMPA和血清素能受体在青春期前雄性大鼠催乳素分泌控制中的相互作用。为此，对16日龄和23日龄的雄性大鼠单独或与AMPA（AMPA受体激动剂）联合使用5-羟色氨酸（5-HTP，血清素合成前体）加氟西汀（血清素再摄取阻滞剂）、8-OH-DPAT（5-HT1A受体激动剂）、DOI和α-Me-5-HT（5-HT2受体激动剂）、1-苯基双胍（5-HT3受体激动剂）进行处理。所得结果表明：（a）5-HT1A受体的激活在第16天刺激催乳素分泌，而在第23天抑制其分泌；5-HT2受体的激活在第16天和第23天均刺激催乳素分泌，而5-HT3受体的激活仅在第23天抑制催乳素释放；（b）AMPA受体的激活在第23天抑制催乳素分泌，但在第16天则无此作用；（c）在催乳素分泌的调节中，5-HT2和AMPA受体之间存在明显的相互作用，DOI的刺激作用被AMPA阻断。
