Spermatogenesis, fertility and sexual behavior in a hypospadiac mouse model

Administering of flutamide to pregnant mice causes hypospadias in male offspring. We investigated spermatogenesis, fertility and sexual behavior in this hypospadiac mouse model.

Male offspring exposed to flutamide during the embryonic period were divided into hypospadiac group 1 and normal external genitalia group 2. Control group 3 consisted of male offspring not exposed to flutamide. We analyzed the spermatogenesis, epididymides sperm motility, in vitro fertilization rate and sexual behavior of each mouse.

There were no significant differences in the weight of the testes or mean seminiferous tubular diameter in the groups. The number of apoptotic germ cells per unit area was not significantly different in the 3 groups. In groups 1 to 3 there were no significant differences in the mean epididymides sperm motility rate plus or minus standard deviation (62.6% +/- 10.0%, 57.2% +/- 7.0% and 67.0 +/- 7.6%) or in the in vitro fertilization rate (52%, 48% and 48%, respectively). However, there were significant differences in groups 1 to 3 in mean mounting frequency (0, 29 +/- 4.0 and 12.4 +/- 4.5 times per hour) and mean intromission frequency (0, 24.4 +/- 3.5 and 3.8 +/- 1.5 times per hour, respectively). Females coupled with group 1 or 2 male mice did not achieve pregnancy.

These results suggest that spermatogenesis, sperm motility and fertilization in vitro were unaffected in hypospadiac mice but sexual motivation and arousal were deficient.