[Effect of an estrogen-progestin preparation alone and in combination with amizil on the structure and electrophoretic parameters of oocytes and early rat embryos].
An increasing contraceptive effect at a combined administration of steroid drugs with neurotropic substances--M-cholinolytic benactyzine, makes the problem on the character and mechanism of their action. In the experiments performed in rats, under effect of ethinyl estradiol and norethisteron acetate, and especially at their combination with benactyzine, the first signs of overmaturation are revealed in oocytes situating in the follicular cavity. Therefore, oocytes revealed in the rat fallopian tubes leave behind the development of the control oocytes. The drugs investigated, influencing maturation and ovulation mechanisms of oocytes, produce certain physiological and morphological changes in ovaries of the test rats. This, evidently, defines the mechanism of their elevated contraceptive action. Overmaturation of oocytes in follicles, ovulation at later developmental stages results in increasing amount of degenerative forms of embryos and in disturbance of their development.