Insel T R, Young L, Witt D M, Crews D
Laboratory of Neurophysiology, National Institute of Mental Health, Poolesville, MD 20837, USA.
J Neuroendocrinol. 1993 Dec;5(6):619-28. doi: 10.1111/j.1365-2826.1993.tb00531.x.
Specific brain receptors for oxytocin have been described in several mammalian species. The distribution of these receptors differs greatly across species and in the rat, receptor binding in specific brain regions appears to depend upon gonadal steroids. This study used in vitro receptor autoradiography to examine the effects of testosterone on oxytocin receptor binding in the mouse forebrain. Three groups of male mice were compared: castrates treated with blank capsules, castrates treated with testosterone filled capsules, and intact males. Irrespective of steroid treatment, the distribution of oxytocin receptors in mouse forebrain differed markedly from patterns previously described in the rat. In addition to these species differences in receptor distribution, testosterone had effects in the mouse which differed from the induction of receptors previously reported in the rat. In the mouse ventromedial nucleus of the hypothalamus, binding in the untreated castrate males was approximately double that observed in either the intact or the testosterone-treated castrates. In other regions of the mouse brain, such as the intermediate zone of the lateral septum, binding to oxytocin receptors was increased with testosterone treatment. These results suggest that the brain oxytocin receptor varies across species not only in its distribution but also in its regional regulation by gonadal steroids. These apparently paradoxical changes in oxytocin receptor binding may result from either direct or indirect effects of gonadal steroids in mouse brain.
在几种哺乳动物中已描述了催产素的特定脑受体。这些受体的分布在不同物种间差异很大，在大鼠中，特定脑区的受体结合似乎取决于性腺类固醇。本研究使用体外受体放射自显影技术来检测睾酮对小鼠前脑催产素受体结合的影响。比较了三组雄性小鼠：用空白胶囊处理的去势小鼠、用填充睾酮的胶囊处理的去势小鼠和完整雄性小鼠。无论类固醇处理如何，小鼠前脑催产素受体的分布与先前在大鼠中描述的模式明显不同。除了受体分布的这些物种差异外，睾酮在小鼠中的作用与先前在大鼠中报道的受体诱导作用不同。在下丘脑的小鼠腹内侧核中，未处理的去势雄性小鼠的结合约为完整或睾酮处理的去势小鼠的两倍。在小鼠脑的其他区域，如外侧隔的中间区，睾酮处理后与催产素受体的结合增加。这些结果表明，脑催产素受体不仅在分布上而且在性腺类固醇的区域调节上因物种而异。催产素受体结合中这些明显矛盾的变化可能是由于性腺类固醇对小鼠脑的直接或间接作用所致。
