Arq Bras Endocrinol Metab 2013;57(6):437-444
New insights into steroidogenesis in normo- and hyperandrogenic polycystic ovary syndrome patients
DOI: 10.1590/S0004-27302013000600005
OBJECTIVE: This study sought to examine corticosteroidogenic enzyme activities in normo- and hyperandrogenic polycystic ovary syndrome (PCOS) patients. SUBJECTS AND METHODS: This cohort study included 81 patients with biochemical hyperandrogenism and 41 patients with normal androgen levels. Enzyme activities were assessed according to the serum steroid product/precursor ratios at baseline and after adrenal stimulation. RESULTS: At baseline, in the delta 4 (?4) pathway, hyperandrogenic patients showed greater 17-hydroxylase and 17,20 lyase activities in converting progesterone (P4) into 17-hydroxyprogesterone (17-OHP4) and 17-hydroxypregnenolone (17-OHPE) into androstenedione (A) (p = 0.0005 and p = 0.047, respectively) compared to normoandrogenic patients. In the delta 5 (?5) pathway, the 17-hydroxylase and 17,20 lyase enzymes showed similar activities in both groups. Hyperandrogenic patients presented lower 21-hydroxylase, lower 11?-hydroxylase (p = 0.0001), and statistically significant increases in 3?-hydroxysteroid dehydrogenase II (3?-HSDII) activities (p < 0.0001). Following tetracosactrin stimulation, only the 17,20 lyase activity remained up-regulated in the ?4 pathway (p < 0.0001). CONCLUSION: Hyperandrogenic patients had higher 17,20 lyase activity, both at baseline and after adrenal stimulation. Greater conversion of dehydroepiandrosterone (DHEA) into A with normal conversion of 17-OHPE to 17-OHP4 in hyperandrogenic PCOS patients indicated different levels of 3?-HSDII activity in adrenal cells, and hyperandrogenic patients had lower 11?-hydroxylase and 21-hydroxylase activities.