title: Characterization by high performance liquid chromatography of nuclear metabolites of testosterone in the brains of male rhesus monkeys.
abstract: Testosterone (T) restores the potency of castrated male rhesus monkeys, and our autoradiographic data have demonstrated that 3H-T or its metabolites concentrate in cell nuclei in the corticomedial amygdala, bed nucleus of stria terminalis, preoptic area, and hypothalamus. In rat, 3H-estradiol (3H-E2) is a major nuclear metabolite of 3H-T in areas of the limbic system, but comparable data are lacking for the primate. We have therefore developed an improved technique using high performance liquid chromatography for investigating metabolites of 3H-T that accumulate in cell nuclei in small amounts of tissue obtained from the brain of the rhesus monkey. Two castrated male rhesus monkeys were injected with 5 mCi of 3H-T and were killed 30 min later. In amygdala, preoptic area-bed nucleus of stria terminalis, and hypothalamus, 48-70% of the nuclear radioactivity was in the form of 3H-E2 (Type I tissues). In six other brain areas and in pituitary, 35-85% of the nuclear radioactivity was in the form of 3H-T (Type II tissues), whereas in genital tract tissues, 86-99% of the nuclear radioactivity was in the form of 3'-dihydrotestosterone (3H-DHT) (Type III tissues). In plasma and in supernatants from both Type I and Type II tissues, the proportions of 3H-T were high, and 3H-E2 did not exceed 10% of the total extractable radioactivity. These data suggest that, as in rodents, some of the central actions of T in primates may be mediated by estrogen target neurons.
mesh_terms: D000818:Animals; D001921:Brain / Q000378:metabolism*; D002369:Castration; D002467:Cell Nucleus / Q000378:metabolism*; D002851:Chromatography, High Pressure Liquid / Q000379:methods; D008253:Macaca mulatta; D008297:Male; D009928:Organ Specificity; D013347:Subcellular Fractions / Q000378:metabolism; D013739:Testosterone / Q000378:metabolism*; D014316:Tritium
chemical_list: D014316:Tritium; D013739:Testosterone