Distribution of steroidogenic enzymes involved in androgen synthesis in polycystic ovaries: an immunohistochemical study

To find an explanation for the possible working mechanism of laparoscopic o varian electrocautery for the treatment of anovulation in polycystic ovaria n syndrome (PCOS), we evaluated the distribution of steroidogenic enzymes i nvolved in the synthesis of ovarian androgens in surgical pathology specime ns of entire polycystic ovaries. A total of 13 formalin-fixed and paraffin- embedded samples of the ovaries of patients with clinically proven PCOS wer e immunostained with specific antibodies against cholesterol side-chain-cle avage enzyme (P450scc), 3 beta-hydroxysteroid dehydrogenase (3 beta-HSD), 1 7 alpha-hydroxylase (P450c17) and adrenal 4-binding protein (Ad4BP), a tran scription factor of steroidogenic enzymes. Follicular theca cells of all ov aries demonstrated marked immunoreactivity for Ad4BP, P450scc, 3 beta-HSD a nd P450c17. Granulosa cells of seven ovaries expressed Ad4BP, while granulo sa cells of three ovaries also showed P450scc. In the granulosa cells of ai l ovaries, 3 beta-HSD and P450c17 immunoreactivity was not observed. In the stroma, luteinized cells of most ovaries demonstrated Ad4BP, P450scc, 3 be ta-HSD and P450c17 immunoreactivity, but at a much lower level compared wit h the follicular theca cells. Non-luteinized stromal cells sporadically dem onstrated Ad4BP, P450scc, 3 beta-HSD and P450c17 immunoreactivity. The stro mal steroidogenic cells were mainly located in the ovarian cortex, except f or some hilus steroidogenic cells. These data demonstrate that in polycysti c ovaries, androgens are mainly produced in the follicular theca cells and to some extent in luteinized stromal cells. This suggests that the working mechanism of laparoscopic electrocautery of the ovary is primarily explaine d through the reduction of ovarian hyperandrogenism by coagulation of folli cular theca cells and concomitant stroma.