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dc.contributor.authorClifton, Donald K.en_US
dc.contributor.authorSteiner, Robert A.en_US
dc.contributor.authorBremner, William J.en_US
dc.date.accessioned2008-10-17T20:40:25Z
dc.date.available2008-10-17T20:40:25Z
dc.date.issued1982-12en_US
dc.identifier.citationEndocrinology. 1982 Dec;111(6):2055-61en_US
dc.identifier.urihttp://hdl.handle.net/1773/4305
dc.description.abstractOur 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.isoen_USen_US
dc.publisherEndocrine Societyen_US
dc.subjectreifenstein's syndromeen_US
dc.subjectandrologyen_US
dc.subject5-alpha reductase inhibitorsen_US
dc.subjectgonadotropinsen_US
dc.subjectklinefelter's syndromeen_US
dc.subjectmale contraceptionen_US
dc.subjecttestosteroneen_US
dc.subjectspermatogenesisen_US
dc.subjectcolchicineen_US
dc.subject.meshLuteinizing Hormone, blooden_US
dc.subject.meshAnimalsen_US
dc.subject.meshFollicle Stimulating Hormone, blooden_US
dc.subject.meshDelayed-Action Preparationsen_US
dc.subject.meshDose-Response Relationship, Drugen_US
dc.subject.meshCastrationen_US
dc.titleRegulation of luteinizing hormone pulse frequency and amplitude by testosterone in the adult male raten_US
dc.typeArticleen_US


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