[Changes in the secretion of gonadoliberin, gonadotropins, and ovarian hormones in rats under chronic exposure to low concentrations of methylmethacrylate].

: Chronic influence of small concentrations of methylmethacrylate in inhalations (at the level of a maximum permissible dose of 50 mg/m3 and in its 10-fold excess) after short-term enhancement of the hypothalamo-hypophyseo-gonad system (in one month after exposure to a dose at maximum permissible concentration) is quickly followed by suppression of its function. The use of methylmethacrylate for 4 months revealed a decrease in ovarian mass, the blood level of progesterone and a rise of secretion of FSH and LH with a simultaneous decrease in the level of gonad-releasing hormone in the mediobasal hypothalamic structures. It indicates primary gonad damage of the reproductive system and preservation of a normal reaction of the hypothalamohypophyseal factor, responding by activation on the feedback principle. In 4 months a high embryotoxic and teratogenic effect of methylmethacrylate was observed.