TUESDAY, March 17 (HealthDay News) -- Ovaries from women with polycystic ovarian syndrome (PCOS) produce high levels of nerve growth factor, and mice overproducing nerve growth factor in the ovaries develop cystic ovarian morphology and similar reproductive abnormalities as PCOS patients, according to research published online March 5 in Endocrinology.
Gregory A. Dissen, Ph.D., from Oregon National Primate Research Center--Oregon Health & Science University in Beaverton, Ore., and colleagues measured ovarian nerve growth factor, a protein that normally facilitates follicular development and ovulation, in patients with PCOS and generated mice overexpressing nerve growth factor in the ovaries.
The investigators found that PCOS patients had higher levels of nerve growth factor in ovarian follicular fluid and higher production of nerve growth factor from granulosa cells. Ovaries from the engineered mice were hyperinnervated by sympathetic nerves. Antral follicle growth was arrested leading to accumulation of intermediate size follicles, and the mice had a reduced ovulatory response, delayed puberty and reduced fertility, the researchers report. Sustained higher levels of luteinizing hormone, which the authors note is observed in more than 90 percent of PCOS patients, increased the incidence of ovarian follicular cysts in the transgenic mice compared with normal mice.
"These results suggest that overproduction of ovarian nerve growth factor is a component of polycystic ovarian morphology in both humans and rodents, and that a persistent elevation in plasma luteinizing hormone levels is required for the morphological abnormalities to appear," Dissen and colleagues conclude.