Pang S F, Dubocovich M L, Brown G M
Clark Institute of Psychiatry, Toronto, Ont., Canada.
Biol Signals. 1993 Jul-Aug;2(4):177-80. doi: 10.1159/000109490.
Melatonin is synthesized and secreted by pineal gland, retina, harderian gland, lacrimal gland, and gut. It is a lipid-soluble molecule with ubiquitous distribution and multifarious functions. Thus, along with the better established sites of melatonin action, such as brain, retina, and pituitary, direct melatonin actions on other peripheral tissues should also be considered. The presence of melatonin receptors in peripheral tissues was rightfully hypothesized. Earlier studies on melatonin receptors had limited success. The advent of 2-[125I]iodomelatonin, a labelled melatonin agonist with a specific activity as high as 2,200 Ci/mmol, has allowed the studies of melatonin receptors with picomolar affinity and femtomolar density. Putative melatonin receptors demonstrated by autoradiography and/or radioreceptor assay in gut, kidney, lung, heart, vas deferens, and blood vessels are discussed.
褪黑素由松果体、视网膜、哈德氏腺、泪腺和肠道合成并分泌。它是一种脂溶性分子，分布广泛，功能多样。因此，除了褪黑素作用较为明确的部位，如大脑、视网膜和垂体，还应考虑其对其他外周组织的直接作用。外周组织中存在褪黑素受体这一假设是合理的。早期关于褪黑素受体的研究成效有限。2-[125I]碘褪黑素作为一种标记的褪黑素激动剂，其比活度高达2200 Ci/mmol，它的出现使得对具有皮摩尔亲和力和飞摩尔密度的褪黑素受体的研究成为可能。本文讨论了通过放射自显影和/或放射受体分析在肠道、肾脏、肺、心脏、输精管和血管中证实的假定褪黑素受体。
