The aim of our in vitro studies was to understand the role of
leptin in controlling proliferation, apoptosis, and protein kinase A
(PKA) in human ovarian cells. We analyzed the in vitro effects of
leptin (0, 1, 10 or 100 ng/ml) on the accumulation of
proliferation-related peptides (PCNA, cyclin B1), apoptosisassociated peptide (Bax) and the intracellular signaling molecule PKA in cultured human granulosa cells using
immunocytochemistry and Western immunoblotting. It was
observed that leptin stimulated in a dose-dependent manner the
accumulation of PCNA (at doses 1-100 ng/ml), cyclin B1 (at
doses 10 or 100 ng/ml), Bax (at doses 10 or 100 ng/ml) and PKA
(at doses 1-100 ng/ml) in cultured human ovarian cells. These
observations suggest the ability of leptin to control directly
human ovarian cell functions: proliferation, apoptosis, and
intracellular messenger PKA.