The presence of luteinized unruptured follicle syndrome and altered folliculogenesis in rats with surgically induced endometriosis.

OBJECTIVE

Our purpose was to determine in the rat model whether endometriosis could influence ovarian function by altering oocyte release or folliculogenesis.

STUDY DESIGN

We histologically examined the ovaries of reproductively cycling rats with (n = 16) and without (n = 10) surgically induced endometriosis. The rats in these two groups were further subdivided into unilaterally ovariectomized or ovarian-intact groups. Serial sections of ovaries were examined, and follicular development and frequency of luteinized unruptured follicles were determined.

RESULTS

A significant tenfold increase in the number of luteinized unruptured follicles was observed in the ovaries from rats with endometriosis (2.7 per rat) compared with unoperated and sham-operated control groups (overall mean 0.26 per rat, p < 0.05). Additionally, ovaries from unilateral ovariectomized animals with endometriosis contained four times as many luteinized unruptured follicles (four per rat) as did the ovaries from bilaterally ovarian-intact rats with endometriosis (1.40 per rat, p < 0.01). Fewer follicles were present in rats with endometriosis (180 follicles per ovary) than in control rats (231 follicles per ovary, p < 0.05).

CONCLUSION

In the rat model the presence of ectopic endometrium is associated with an increased frequency of luteinized unruptured follicles and altered follicular development.