Effect of Lipopolysaccharide on Progesterone Production during Luteinization of Granulosa and Theca cells In Vitro

The aim of this study is to examine the effect of lipopolysaccharide (LPS) on progesterone production during luteinization of granulosa and theca cells isolated from bovine large follicles. Granulosa and theca cells isolated from large follicles of bovine ovaries were exposed to LPS under appropriate hormone conditions in vitro. Progesterone (P4) production in theca cells, but not granulosa cells, was decreased by long‐term exposure of LPS. Long‐term exposure of LPS suppressed the gene expression of luteinizing hormone receptor in theca cells. Although long‐term exposure of LPS did not affect the expression of steroidogenic acute regulatory protein (StAR) and 3β‐hydroxy‐steroid dehydrogenase (3β‐HSD) genes, it did inhibit the protein expression of StAR and 3β‐HSD in theca cells. These findings suggest that theca cells, rather than granulosa cells, are susceptible to LPS during luteinization and that LPS inhibits P4 production by decreasing protein levels of StAR during luteinization of theca cells.