Abstract
The anogenital distance of female rat fetus on the 21st day of gestation was measured by sliding caliper (macroscopic method) or on the sagittal sections of. the pelvic region of female fetus under a microscope equipped with a micrometer (microscopic method). The anogenital distances of 190 intact female fetuses were 1.07±0.21mm with macroscopic method and 0.72±0.13mm with microscopic method, respectively, and also significant correlations were observed between the fetal body weight and the anogenital distance. Following maternal subcutaneous administrations of various doses of norethandrolone and methyltestosterone for 4 days from the 17th to 20th day of gestation, dose dependent extensions in the anogenital distance of female fetuses were observed, but macroscopic method showed a remarkably less sensitivity compared with microscopic method. The log-dose-response relationships were obtained on the relative values of the anogenital distance to the fetal body weight with microscopic method, and the relative potency of norethandrolone to methyltestosterone was assumed to be 0.191 with fiducial limits of 0.135-0.257.
