Follicle-stimulating hormone enhances somatomedin C binding to cultured rat granulosa cells. Evidence for cAMP dependence.

摘要: The ovarian granulosa cell has recently been shown to be the site of Somatomedin C (Sm-C) production, reception, and action. To further elucidate relevance Sm-C physiology, we have undertaken study regulation its receptor under in vitro conditions using a primary culture rat cells. Granulosa cells cultured without treatment for 72 h displayed limited, albeit measurable, specific binding. However, continuous with increasing concentrations follicle-stimulating hormone (FSH) duration 72-h incubation period resulted dose-dependent increments binding (1.7-, 2.9-, 3.9-, 3.6-fold increases over untreated controls 50, 100, 180, 330 ng/ml FSH, respectively). This apparent up regulatory action FSH proved time-dependent, minimal time requirement 24-48 h. was similarly enhanced following elevation intracellular cAMP content by series cAMP-generating agonists, inhibition cAMP-phosphodiesterase activity, or provision nondegradable analogs. Our findings indicate that high dose forskolin, like is capable augmenting itself, relatively inactive low forskolin synergizes this regard, but combined maximal stimulatory doses both agonists does not prove additive. Taken together, these observations exerting effect on cAMP, purported second messenger, may play an intermediary role regard.