Effects of Dietary Arginine Deficiency on the Reproductive Function of the Rat
A series of experiments were conducted with prepubertal, postpubertal, pregnant and lactating rats to explore the possible role of arginine as an essential dietary component for normal sexual maturation and reproductive performance. Dietary arginine deprivation imposed before mating resulted in reduced fertility. When pregnant rats were fed an arginine-deficient diet, both the placental and fetal development were retarded at the end of gestation. The maternal organism was affected as indicated by altered tissue composition and urinary metabolites. The use of pair-fed controls revealed that the adverse effects of dietary arginine deprivation on pregnancy was not a result of reduced food intake. Consuming an arginine deficient diet during gestation also interfered with the nursing performance in early stages of lactation which could be eventually corrected by replenishing arginine after parturition. Deletion of arginine from the diet after paturition did not have an immediate effect on nursing performance. The adverse effect, however, became apparent toward the late stage of lactation. The effects of arginine deficiency on lactation were the consequence of both amino acid deficiency and energy deficiency. Dietary arginine was demonstrated to be required for optimal mammary growth induced by gestation or steroid hormone administration. Maternal arginine deficiency interfered with the prenatal and postnatal development of the offspring. The defects produced in utero persisted when the pups continued to be nursed by arginine-deficient dams after birth but can be corrected by foster-nursing with control dams. Dietary arginine deprivation imposed since weaning delayed sexual maturation more than could be accounted for by impairment of growth. More than 0.28% arginine was required to maintain the normal timing of puberty and more than 0.84% arginine was required to support normal sexual maturation as reflected by ovarian weight and ovulation rate at the time of puberty. The possible mechanism(s) that are responsible for the delay of puberty caused by dietary arginine deprivation was explored. It is concluded from this study that the amino acid arginine, which has often escaped nutritional recognition for its importance, is in fact a dietary essential nutrient for both immature and mature female rats.
University of Illinois - Urbana-Champaign
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University of Illinois at Urbana-Champaign