A CASE OF SPONTANEOUS TRUE HERMAPHRODITISM IN THE RAT WITH EVIDENCE OF FEMALE CHARACTER

Abstract

Spontaneous true hermaphroditism in a rat is reported. This animal was a unilateral hermaphrodite composed of a testis on the left and an ovotestis on the right, although the external genitalia was masculine. In the present case, there were epididymides and vasa deferentia on both sides, an oviduct and a uterine horn on the right side, and seminal vesicles dorsal to the uterus, but prostate glands and the external orifice of vagina were absent. The ovotestis, unlike the other cases of hermaphroditic rats, was composed of a predominant ovarian tissue and a small area of testicular tissue.
The present animal died by a single administration, i.e. the first administration in a repeated dose oral toxicity study, of a test compound having sex difference in the lethal toxicity. The dose given to the animal is expected to cause lethal effects in females but not in males, and the sex difference is presumed to depend on the different activity of S-oxidation by cytochrome P-450, the drug-metabolizing exzyme of the liver. These matters suggest that this animal had been enzymatically female.