Plasma 5 alpha-dihydrotestosterone and testosterone in the bullfrog, Rana catesbeiana: stimulation by bullfrog LH
General and Comparative Endocrinology 33(1): 122-132
ISSN/ISBN: 0016-6480 PMID: 303585 DOI: 10.1016/0016-6480(77)90134-4
Effects of purified bullfrog (R. catesbeiana) LH [luteinizing hormone] and FSH [follicle stimulating hormone] on plasma levels of the androgens, testosterone (T), and 5.alpha.-dihydrotestosterone (DHT), were studied using adult male bullfrogs. Rana LH was considerably more potent than Rana FSH in stimulating increased plasma androgen levels in hypophysectomized and intact animals. Simultaneous injection of Rana FSH or ovine PRL [prolactin] with Rana LH, over a 10-day period, did not alter the LH-induced increase in plasma androgens. More DHT than T was present in plasma after LH injection. Castration abolished plasma DHT and greatly reduced plasma T. DHT is a major testicular steroid, and testicular androgen secretion is stimulated primarily by LH in the bullfrog.