EFFECT OF COCAINE ON THE PRODUCTION OF PUBERTY-ACCELERATING PHEROMONEBY MALE-MICE

This study examined whether chronic cocaine exposure could reduce repr oductive fitness of adult male mice by interfering with their producti on of the puberty-accelerating pheromone, an androgen-dependent urinar y pheromone that accelerates puberty in juvenile female mice. Administ ered at a high dose of 60 mg/kg body weight/day, cocaine caused mortal ity, body weight loss, and suppression of circulating testosterone dur ing the first week of treatment. However, at 40 mg/kg/day, it resulted in little adverse effect on these parameters. Animals showed habituat ion to repeated cocaine exposure by regaining part of the lost weight and reelevating suppressed testosterone level at later stages of treat ment. Urine samples collected from animals receiving 60 mg/kg cocaine daily for 2 weeks lost the puberty-accelerating effect. However, neith er a 3-day treatment of the same dose nor a lower dose of 40 mg/kg red uced the effectiveness. The diminished effect of cocaine-treated male mouse urine might reflect lowered testosterone levels with a lag of 10 to 15 days, similar to that of castrated male mouse urine. These resu lts indicate that cocaine has no direct effect on the production of pr iming pheromone, and its metabolites in the urine did not affect the r esponse of juvenile females to the pheromone.