[Cytogenetic study of the effect of gossypol on mouse germ cells].

The clastogenic and mutagenic activities of a new antifertility and antitumor agent gossypol were studied in the mouse male germ cells. Results of the present work indicate that at the doses 125 and 250 mg/kg the drug does not significantly increase frequencies of the micronuclei in the early spermatids and sperm head abnormalities. Hence, genotoxic influence can not be proposed as responsible for the antifertility effect of gossypol.

[Mechanism of action of vitamin A on cell differentiation and function].

The vitamin A effects on cell proliferation, differentiation and functioning might be due to its influence on genome expression at the level of regulation of the transcription of certain genes, posttranscriptional modification of mRNA levels, or changes in the membrane structural-functional organization. Vitamin A can affect the biosynthesis of various proteins, including those involved in regulation of development and cell functioning or determining cell sensitivity to hormones and hormone-like factors. Vitamin A can also influence the formation of secretory proteins which play the role of hormones.