Impact of circulating estradiol on melatonin binding sites in discrete areas of the female rat brain.
The distribution of 125I-melatonin binding sites in 6 discrete brain regions of female rats at the estrous stage and the effects of ovariectomy and subsequent 17 beta-estradiol treatment on these binding sites were studied. Specific binding of 125I-melatonin was found in the hypothalamus, medulla-pons, hippocampus, cerebellum, striatum and parietal cortex of the female rats. Ovariectomy produced a large estradiol-reversible decrease in 125I-melatonin binding in the medulla-pons and hypothalamus. In contrast, 125I-melatonin binding sites in the other brain regions were generally unaffected by ovariectomy or estradiol. The estradiol-regulated changes in melatonin binding in the hypothalamus and medulla-pons may reflect the role of a specific estradiol-melatonin interaction in the coordination of the neuroendocrine reproductive axis.
D000818:Animals; D001665:Binding Sites; D001921:Brain / Q000378:metabolism*; D004958:Estradiol / Q000097:blood*; D005260:Female; D007031:Hypothalamus / Q000378:metabolism; D008526:Medulla Oblongata / Q000378:metabolism; D008550:Melatonin / Q000378:metabolism*; D010052:Ovariectomy; D011149:Pons / Q000378:metabolism; D051381:Rats
D004958:Estradiol; D008550:Melatonin