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Regulation of luteinizing hormone pulse frequency and amplitude by testosterone in the adult male rat

Show simple item record Clifton, Donald K. en_US Steiner, Robert A. en_US Bremner, William J. en_US 2008-10-17T20:40:25Z 2008-10-17T20:40:25Z 1982-12 en_US
dc.identifier.citation Endocrinology. 1982 Dec;111(6):2055-61 en_US
dc.description.abstract Our objective was to gain a better understanding of the role of testosterone (T) in regulating the minute to minute dynamics of LH secretion in the adult male rat. To this end, we examined the patterns of blood LH levels in intact animals and evaluated the effect of small physiological doses of T on mean blood LH and FSH levels and on LH pulse frequency and amplitude in the castrate animal. The intact rat exhibited low frequency (period, approximately 145 min) and low amplitude (approximately 16 ng/ml) LH pulses. After castration, LH pulse frequency (period, approximately 20 min) and amplitude (approximately 118 ng/ml) increased dramatically over that of intact animals. T, administered to castrate rats through Silastic implants, caused a dose-dependent and parallel reduction in mean blood LH and FSH levels. The lowest T dose, which increased mean plasma T levels to 0.5 ng/ml above those of the sham-treated castrates, produced a significant reduction in LH pulse frequency, with a significant increase in pulse amplitude. The next highest T dose caused a reduction in pulse amplitude to a value significantly lower than that in the sham-treated castrates. The highest T dose, which produced steady state mean plasma T levels (approximately 1.6 ng/ml) less than the mean level of the intact group (approximately 2.2 ng/ml), caused a profound reduction in pulse frequency to lower than that of the intact group. These observations demonstrate that T can exert a complex, dose-dependent effect on LH secretory dynamics and imply that one important site of T-mediated negative feedback is the brain's LHRH pulse generator. en_US
dc.language.iso en_US en_US
dc.publisher Endocrine Society en_US
dc.subject reifenstein's syndrome en_US
dc.subject andrology en_US
dc.subject 5-alpha reductase inhibitors en_US
dc.subject gonadotropins en_US
dc.subject klinefelter's syndrome en_US
dc.subject male contraception en_US
dc.subject testosterone en_US
dc.subject spermatogenesis en_US
dc.subject colchicine en_US
dc.subject.mesh Luteinizing Hormone, blood en_US
dc.subject.mesh Animals en_US
dc.subject.mesh Follicle Stimulating Hormone, blood en_US
dc.subject.mesh Delayed-Action Preparations en_US
dc.subject.mesh Dose-Response Relationship, Drug en_US
dc.subject.mesh Castration en_US
dc.title Regulation of luteinizing hormone pulse frequency and amplitude by testosterone in the adult male rat en_US
dc.type Article en_US

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