Testosterone-induced copulatory behavior is affected by the postcastration interval.

J T Clark; P E Micevych; V Panossian; A K Keaton

doi:10.1016/0149-7634(94)00049-7

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Testosterone-induced copulatory behavior is affected by the postcastration interval.

J T Clark·P E Micevych·V Panossian·A K Keaton

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Abstract

A well entrenched hypothesis regarding hormonal action is that as the time interval following hormonal deprivation increases there is a corresponding decrease in the sensitivity of the system to the effects of hormone replacement. With this in mind, we examined the effects of a prolonged period of hormonal deprivation (9 mo), and compared these to the effects of a shorter period (1 month), on the restoration of copulatory behavior and seminal vesicle weights. Castration of sexually vigorous male Long-Evans rats at 6 mo of age was followed by the virtual disappearance of ejaculatory behavior within 1 mo. Testosterone (T) was administered (5 mm or 20 mm T-containing Silastic capsules) either 1 or 9 mo after castration, and copulatory tests were conducted 3, 7, 10, 14, and 17 days later. 5 mmT and 20 mmT were equally effective in restoring behavior in the rats treated 1 mo after castration. In contrast, 5 mmT was more effective in inducing copulatory behavior than 20 mmT in the rats treated 9 mo after castration. The time course to maximal effect was longer in the rats given T 9 mo after castration. Rats were sacrificed 21 days after T administration. Expressed seminal vesicle weights and plasma testosterone were increased in a dose-dependent manner independent of the postcastration interval. These data indicate that somatic and behavioral effects of T are differentially modified by the period of preceding hormonal deprivation.

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Aging Animals Copulation Dose-Response Relationship, Drug Drug Implants Ejaculation Female Male Orchiectomy Rats Seminal Vesicles Sexual Abstinence Testosterone Time Factors Journal Article Research Support, U.S. Gov't, Non-P.H.S.Research Support, U.S. Gov't, P.H.S.

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J T Clark, P E Micevych, V Panossian, A K Keaton. 1995. Testosterone-induced copulatory behavior is affected by the postcastration interval.. https://doi.org/10.1016/0149-7634(94)00049-7

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