Abstract
The new 5-HT agonist 5-hydroxy-3-(di- n-propylamino)chroman (5-OH-DPAC), 0.025-3.2 mg:kg-1, produced a marked facilitation of male rat sexual behaviour, characterized by a decrease in the number of intromissions preceding ejaculation and in time to ejaculation. The compound is in this regard as efficacious as 8-OH-DPAT, but about 3 times less potent. Buspirone, 2-4 mg:kg-1, also produced a facilitation of the male rat sexual behaviour, but with less efficacy and with considerably less potency than either 8-OH-DPAT or 5-OH-DPAC. In the experiment where 5-OH-DPAC and 8-OH-DPAT were directly compared, the display of flat body posture was recorded immediately before the sexual behaviour observations. These observations indicate: (1) that the occurrence of this behavioural syndrome does not interfere with the performance of sexual behaviour in 8-OH-DPAT treated rats; and (2) at doses where the male rat sexual behaviour was affected to the same degree by 8-OH-DPAT and 5-OH- DPAC, only the former compound produced the flat body posture.