BECK, K.B.; YAHR, P.I.: The Role of Androgren Aromatization in Mediating Male Rat Sex Behavior

This experiment served to further define the role of androgen aromatization in male rat reproductive behavior. The hormones tested are analogs of testosterone (T), an aromatizable compound, and 6α-fluoroT, a non-aromatizable compound, but both stimulate reproductive behavior. These two hormones were examined in the presence of either of two aromatase inhibitors, androstatriedione (ATD) and Fadrozole. Male Long-Evans rats were screened for copulatory behavior with female Spraque-Dawley rats in induced estrus. Reliable copulators were castrated and placed in one of six groups. Three groups received daily injections of testosterone propionate (TP), while the other groups received 6α-flurotesterone propionate (6α-fluoroTP). One TP and one 6α-fluoroTP group received a Fadrozole filled mini-pump, ATD in a silastic capsule, or an empty silastic capsule at the time of castration. One week following the surgery, the males were tested for sex behavior on a weekly basis for 10 weeks. Data that recorded include latency to mount and intromit, number of mounts and intromissions, latency to ejaculate (from first intromission), and the latency to resume mating following an ejaculation. The mating behaviors induced by TP and 6α-fluoroTP were inhibited in the presence of Fadrozole or ATD. Further work needs to be done to establish whether 6α-fluoroTP is, in fact, aromatizable in vivo and to determine the exact mechanisms of the aromatase inhibitors used.