[Dynamics of changes in the concentration of luteinizing hormone in the pituitary and plasma and estrogens in blood of female rats during sexual maturation].

The dynamics of LH content in hypophysis and blood and oestrogen content in blood was studied in female rats from the 1st till the 42nd day of postnatal development. The two peaks of LH content in blood on the 18th and 22nd days correspond to the maximum accumulation of the hormone in hypophysis. The 3rd peak on the 41st day is somewhat behind the accumulation of the hormone in hypophysis (37th day). At the moment of vaginal opening, both the hormone synthesis and the secretion sharply decreased. The measurable quantities of oestrogens were found in blood beginning from the 8th day of life. The maximum level of oestrogens was noted from the 13th till the 16 day. These results suggest the absence of distinct interrelations of the feed-back type between hypothalamus, hypophysis and gonads.