Expression and cellular distribution of cytosolic phospholipase A2 in the rat ovary

Cellular expression of cytosolic phospholipase A2 (cPLA2) was investigated in the rat ovary in different endocrine states. Its mRNA expression was detected by RT-PCR. The immunohistochemistry identified an intense signal for cPLA2 in oocytes. Granulosa and thecal cells in growing follicles were negative, but turned positive during the periovulatory period, whereas those in atretic follicles were highly immunoreactive. The immunoreactive signal was modest in newly formed corpora lutea (CL) but intensified in functionally and morphologically regressing CL. These results show a broad but specific distribution of cPLA2 in ovarian cell types, and suggest its role in ovulation, CL regulation and apoptotic processes.