Dietary arginine and sexual maturation of the female rat

The effects of dietary arginine deficiency on sexual maturation were examined in the female rat. Consumption of a diet devoid of arginine since weaning delayed the onset of puberty. Weight at vaginal opening and weight at first estrus were significantly greater in the arginine-deficient rat than in the control rat. Arginine deficiency appeared to have a specific effect on the development of reproductive function since puberty in arginine-deficient animals was delayed more than could be accounted for by impairment of growth. The specific effect of arginine deficiency was also indicated by reduced weights of the reproductive tissues after 15 weeks of experimental feeding when compared with the growth-matched controls. Sexual maturation was also examined in rats fed diets containing graded levels of arginine (1.12, 0.84, 0.56, 0.28 or 0%). Vaginal opening and first estrus were delayed by feeding diets containing 0.28 or 0% arginine. Uncoupling of these two events also occurred in the majority of the rats fed these two diets. In spite of normal timing of puberty, maturing rats fed a diet with 0.56 of 0.84% arginine had reduced ovarian weight and first ovulation rate when compared with rats fed the control diet (1.12% arginine). It is concluded that more than 0.84% dietary arginine was required for growing rats to support normal sexual maturation.