[Factors regulating the differentiation of somatic cells of mammalian ovarian follicles].

Experimental data on regulation of the cytodifferentiation of theca and the granulosa cells in mammalian ovaries are reviewed, in addition to mechanisms of cooperative interactions of these cell types in steroidogenesis. Evidence is provided on the gonadotropin induced differentiation in the cultured ovarian somatic cells, and on a modifying effect exerted on this process by some central (prolactin, LH-RH, etc.) or local factors (steroids, growth factors, low-molecular fraction of follicular fluid, etc.). A possible physiological importance of endocrine and also of auto- and paracrine regulators of differentiation in growth processes and selection of the dominant follicle in the mammalian ovaries is discussed.