Effect of noise stress on male rat fertility, and the protective effect of vitamins C and E on its potential effect

To evaluate the effect of noise on the fertility of male rats, and to assess the effect of vitamins C and E on its potential effect.

Materials and methods:
Forty adult male rats were randomly divided into five equal groups. Group 1 (control) was not exposed to noise. Groups 2–5 were exposed to noise of 90–130 dB and 300–350 Hz from 19.00 to 07.00 h every day for 50 days; group 2 received vitamin C and group 3 received vitamin E. Group 4 received vitamins C and E concomitantly and group 5 received no vitamins. After 50 days, the serum levels of follicle-stimulating hormone (FSH), luteinising hormone (LH) and testosterone were measured. Each rat was then left for 1 week with three female rats, for mating. Pregnant females were killed humanely after 19 days of pregnancy and evaluated for the presence and number of viable, dead and absorbed fetuses.

Results:
The mean serum FSH level was statistically significantly different between the control and groups 2 (P < 0.05) and 5 (P < 0.001). The mean serum LH level differed significantly between the control and groups 2 (P = 0.05), 3 (P < 0.05) and 5 (P < 0.001). The mean serum testosterone level was significantly different between the control and group 5 (P < 0.001). Serum FSH, LH and testosterone levels in group 5 were significantly different from all the others (P < 0.001). The pregnancy rates in females mated with groups 1 and 5 were statistically different (P < 0.05). Comparing groups 1–4, there was no difference in the occurrence of abnormal pregnancy (P > 0.05), but group 5 values were significantly different from the others (P < 0.001).

Conclusion:
These data strongly suggest that noise stress has a significant effect on the fertility of male rats.