Effect of ovarian sex hormones on the pool of free amino acids in maternal tissues of pregnant rats fed a protein-free diet.

The effects of s.c. injections of 5 mug oestrone/kg and 50 mg progesterone/kg on Days 5-7 of gestation were investigated in rats fed a protein-free diet.

Effects of a protein-free diet on amino acids and sex hormones of rats during the early postimplantation stages of pregnancy.

In rats, the effect of a protein-free diet on the maintenance of gestation was investigated during the early postimplantation stages (days 7 to 10). The growth kinetics of the implantation site, the concentrations of free amino acids in the implantation sites as well as in the maternal liver and the levels of sex hormones in the maternal serum were determined. The results of these studies showed that in the whole implantation site, the absolute amounts of DNA, RNA and nitrogen were significantly lower in the rats fed a protein-free diet, the concentrations of essential amino acids decreased in the whole implantation site to the same extent as in the maternal liver.