Dysregulation of cytochrome P450c 17 alpha as the cause of polycystic ovarian syndrome.
Polycystic ovarian syndrome (PCOS) appears to be due to a previously unrecognized type of steroidogenic abnormality, one in which hyperandrogenism arises from a regulatory abnormality (dysregulation) rather than from enzyme deficiency. It appears that PCOS typically arises from masculinized regulation of the androgen-forming enzyme (cytochrome P450c17 alpha) within ovarian thecal cells. This may arise by either excessive stimulation by luteinizing hormone (LH) or by escape from desensitization to LH. We review evidence which is compatible with the concept that the latter situation may result from an intrinsic intraovarian flaw in the paracrine feedback mechanism by which thecal androgen biosynthesis is inhibited and that coexistent adrenal 17-ketosteroid hyper-responsiveness to corticotropin (ACTH) may be due to a similar type of dysregulation of adrenocortical P450c17 alpha.
University of Chicago Pritzker School of Medicine, Illinois.
R L
RL
Rosenfield
R B
RB
Barnes
J F
JF
Cara
A W
AW
Lucky
D000302:Adrenal Cortex / Q000378:metabolism; D000375:Aging / Q000502:physiology; D005260:Female; D006801:Humans; D008954:Models, Biological; D010050:Ovarian Function Tests; D010053:Ovary / Q000166:cytology / Q000503:physiopathology; D011085:Polycystic Ovary Syndrome / Q000209:etiology* / Q000503:physiopathology; D013254:Steroid 17-alpha-Hydroxylase / Q000502:physiology*; D013250:Steroid Hydroxylases / Q000502:physiology*; D013799:Theca Cells / Q000502:physiology
D013250:Steroid Hydroxylases; D013254:Steroid 17-alpha-Hydroxylase