Uterine atrophy in chronic murine toxoplasmosis due to ovarian dysfunction.

Uterine atrophy is a conspicuous finding in Nya:NYLAR female mice chronically infected with Toxoplasma gondii. Administration of 17B-estradiol to infected mice induced a vigorous uterotropic response, i.e., an increase in uterine weight, in endometrial hypertrophy and proliferation, and in the activity of three estrogen-regulated uterine enzymes. These findings rule out a parasite-induced refractoriness of the uterus to estrogen and point to ovarian dysfunction (hypogonadism) as the immediate cause of the uterine atrophy.