| Abstract No.: | A-G1182 |
| Country: | Canada |
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| Title: | SEXUAL BEHAVIOR IN OVARIECTOMIZED WISTAR RATS FOLLOWING VARIED DOSES OF TESTOSTERONE WITH OR WITHOUT ESTROGEN, AND THE EFFECTS OF REPEATED EXPOSURE TO TESTOSTERONE. |
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| Authors/Affiliations: | 1 Sherri Lee Jones*; 1 James G. Pfaus;
1 CSBN/Psychology, Concordia University, Montreal, QC, Canada.
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| Content: | Objectives: We have shown previously that sexually experienced, ovariectomized (OVX) Long-Evans rats treated with acute subcutaneous injections of estradiol benzoate (EB) and testosterone propionate (TP) show both appetitive and consummatory sexual behaviors, at higher frequencies than with either steroid alone. This is identical to the normal sequence of sexual behaviors displayed when OVX females are primed with EB and progesterone (P). A similar pattern is displayed in gonadally intact, aged, acyclic Wistar females, suggesting that EB+TP are acting synergistically to reinstate the full complement of sexual behaviors in rats. This is reminiscent of the ability of estrogen and androgen co-administration to restore sexual arousal and desire in postmenopausal women. To further refine our approach, the present study examined the dose-response effects of TP in OVX Wistar rats with or without a common EB baseline.
Materials and methods: In the first (TP-alone) and second (TP+EB) studies, 5 groups of OVX Wistar rats received varying levels of T in sesame oil (O), (0 ug, 50 ug, 100 ug, 200 ug, or 400 ug), with or without EB (10 ug) administered in combination. In the third study, five groups of animals received oil, EB-alone, EB+P, TP-alone or EB+TP.
Results: No significant differences were found between dose groups in the TP-alone or the EB+TP study on lordosis, although the highest dose of TP increased solicitations throughout the test. In the third study, EB+TP induced rates of lordosis and male responses toward the females (mounts, intromissions, ejaculations) equivalent to those of rats given either EB-alone or EB+P, suggesting that these behaviors are controlled through the actions of EB. However, appetitive solicitations and hops and darts were elevated in animals receiving EB+TP or EB+P, but not in animals receiving either EB-alone or TP-alone. These results show that estrogen alone is sufficient to reinstate the consummatory measure lordosis in OVX females, whereas the combination of estrogen and androgen are necessary for the restoration of rat analogues of sexual desire: appetitive solicitations and hops and darts. Finally, we compared the groups that received 200 ug of T-alone in study one and in study three because the animals in the third study had previous exposure to T whereas the first study did not. Animals in the third study displayed significantly more solicitations, hops and darts, and pacing behavior relative to animals in the first study, and received more mounts, intromissions, and ejaculations from the males.
Conclusion: Thus, both acute and repeated exposure to TP facilitates appetitive sexual behaviors in female rats, although repeated exposure is more robust in this regard.
Supported by grants from NSERC (JGP) and FRSQ (CSBN)
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