ANXIOLYTIC ACTIONS OF DIAZEPAM, BUT NOT OF BUSPIRONE, ARE INFLUENCED BY GENDER AND THE ENDOCRINE STAGE

The effect of diazepam (1.0 mg/kg, ip) and buspirone (5.0 mg/kg, ip) o n the burying behaviour latency (denoting actions on the animals' reac tivity) and on the cumulative burying behaviour (directly reflecting t he experimental anxiety levels), were analyzed in male-, intact female s, at proestrus and metoestrus, and in neonatally-androgenized-rats. A ndrogenization was performed by injecting 60 mu g/rat of testosterone propionate on day 5 after delivery. Two main groups of neonatally-andr ogenized rats were established: A group of animals showing permanent o estrus from the vaginal opening (acyclic females) and a group presenti ng the delayed anovulatory syndrome. Diazepam produced a clear reducti on in experimental anxiety in males and neonatally-androgenized-female s. Particularly important was the anxiolytic effect of diazepam on acy clic females that was accompanied by a significant increase in burying behaviour latency. Conversely, buspirone induced a clear reduction in burying behaviour, without modifying its latency, in all groups regar dless of the gender and the neonatal treatment. Data are discussed on the basis of the androgen participation on the anxiolytic drug effects . A possible age-related benzodiazepine actions in females is suggeste d. (C) 1997 Elsevier Science B.V.