[Nature of the estrous cycle, incidence of anovulation, chromosome gametopathies and fetal death in female rats with 2,4-dichlorophenoxyacetic acid (2,4-D) before pregnancy]. / Kharakter éstral'nogo tsikla, chastota anovuliatsii, khromosomnye gametopatii i émbrional'naia gibel' u krys, pri zatravke samok 2,4-dokhlorfenoksiuksusnoi kislotoi (2,4-D) do beremennosti.

The effect of herbicide--2,4-D, injected before pregnancy begins, on the main parameters of the reproductive function of the female rats has demonstrated that chronic administration in doses 1 mg/kg and 12 mg/kg per day for 2 months results in certain disturbances in the estrus cycle, manifesting as prolongation of the diestrus phase and in changes of estrus and meta-estrus++ duration, as well as in an essential increase in rates of anovulatory cycles. Single administration of the preparation during the preovulatory period (50 mg/kg) produces certain disturbances in the chromosomal complex, manifesting as appearance of numerical chromosomal aberrations. When the administration is acute (10 mg/kg and 50 mg/kg) an essential increase of the embryonal death takes place, in the first case--at the expense of ++pre-implantational, and in the second--both at the expense of pre- and ++post-implantational death. At chronic administration increasing rate of the intrauterine death takes place mainly at the expense of ++post-implantational death of embryos.