Vriend J, Sheppard M S, Borer K T
Department of Anatomy, University of Manitoba, Winnipeg, Canada.
Growth Dev Aging. 1990 Winter;54(4):165-71.
In male Syrian hamsters daily evening melatonin injections resulted in increased circulating levels of growth hormone (GH), as well as a modest increase in body weight. A substantial increase in serum levels of insulin-like growth factor I (IGF-I) was observed in all hamsters receiving evening injections of melatonin for 10 weeks. The melatonin-induced increase in serum IGF-I levels was interpreted as a result of increased release of GH during the 10 week period of melatonin administration. The increase in serum GH and IGF-I was associated with significantly decreased hypothalamic turnover of norepinephrine (NE). Since blocking NE synthesis with alpha methyl-p-tyrosine reduced serum GH, the melatonin-induced increase in GH could not readily be attributed to decreased NE turnover. Highly significant increases in 5-hydroxyindole acetic acid (5HIAA) concentrations and in ratios of 5HIAA to serotonin (5HT) were noted in extracts of hypothalamus and in extracts of brain stem, suggesting a serotonergic component to melatonin-induced increase in GH-induced IGF secretion and subsequent growth.
在雄性叙利亚仓鼠中，每天傍晚注射褪黑素会导致循环生长激素（GH）水平升高，以及体重适度增加。在所有接受傍晚褪黑素注射10周的仓鼠中，观察到血清胰岛素样生长因子I（IGF-I）水平大幅升高。褪黑素诱导的血清IGF-I水平升高被解释为在褪黑素给药的10周期间GH释放增加的结果。血清GH和IGF-I的升高与下丘脑去甲肾上腺素（NE）周转率显著降低有关。由于用α-甲基-p-酪氨酸阻断NE合成会降低血清GH，因此褪黑素诱导的GH升高不太可能归因于NE周转率降低。在下丘脑提取物和脑干提取物中，5-羟吲哚乙酸（5HIAA）浓度以及5HIAA与血清素（5HT）的比率显著升高，这表明血清素成分参与了褪黑素诱导的GH诱导的IGF分泌增加及随后的生长过程。
