Nitric Oxide Synthase Inhibitor N-nitro-L-arginine Methyl Ester Impair Fertility of Female Rats When Given during Early Pregnancy

Abstract

The role of nitric oxide (NO) on fertility of female rats was investigated by oral administration of the NO synthase inhibitor N-nitro-L-arginine methyl ester (L-NAME) (50 or l00mg/kg/day) to rats from days 1-7 of gestation. L-NAME caused a moderate but significant reduction (P<0.05) in number of uterine implants. This antifertility effect was due to an elevation in pre-implantation loss. The inactive stereoisomer D-NAME, on the other hand, had no effect whatsoever on fertiligy. The results suggest that NO is essential for the expression of normal fertility in female rats and NO donors may find applications in the treatment of some forms of female subfertility.