Objective To assess the effect of antipsychotics on the indices of genital organ and sexual function in male rat. Methods A total of 80, 3-month-old male SD rats were randomly divided into four groups. Three groups of rats were orally administered the following antipsychotics respectively for three or six weeks: quetiapine (20 mg/kg), risperidone (2 mg/kg) and haloperidol (2 mg/kg). The rats in control groups were treated by gavage with vehicle (distilled water). Their mating behaviors were evaluated on the last day of three or six weeks' treatment by using receptive female rats. The following day the rats were killed and the indices of testis, epididymis, seminal vesicle and prostate were also measured.Results~Compared with the control group, quetiapine had no effect on the indices of sexual organ and sexual function both at the third week and sixth week. At the third week, epididymis index was significantly decreased in both risperidone group (t=-3.901; P=0.001) and haloperidol group (t=-3.695; P=0.002). At the sixth week, the indices of epididymis (t=-6.077; P<0.001), seminal vesicle (t=-3.
984; P=0.01) and prostate (t=-3.765; P=0.01) were significantly reduced in haloperidol group, but not in risperidone group. The following sexual competence was significantly impaired in both risperidone group and haloperidol group at the third week: libido (assessed in numbers of mounting and intromission), sexual arousability/motivation (in terms of latencies for mounting, intromission), orgasm (in terms of latency for ejaculation) (U=6.5—23; P<0.05—<0.001). At the sixth week, haloperidol also suppressed hit ratio beside above-mentioned parameters, indicating erectile dysfunction (U=19; P=0.019). Risperidone had not significant effect on sexual function at the sixth week.Conclusions Haloperidol and risperidone possibly affect the indices of genital organ and sexual function by the different duration of action in male rats, while quetiapine may have no influence on these indices.