The Effects of Estrogen and Progesterone on the Arterial System of the Uterus of the Cow

Abstract

A study of the uterine arteries of six normal and seven ovariectomized cows by the plastic injection-corrosion technique revealed the following points: The caruncular arterioles of normal cows are extremely coiled. The endometrial arterioles of 13- to 16-mo.-old heifers are essentially straight, while similar arterioles in the uteri of mature cows are more numerous and more highly coiled. These facts appear significant in relation to the lower conception rate encountered in heifers and in relation to the more frequent occurrence of metestrous bleeding in heifers. The disappearance of the endometrial arterioles that normally occurs following ovariectomy can be prevented by administration of the ovarian hormones. Estrogenic hormones appear to be the most effective in this respect. It was not possible by this method to detect differences in the arterial development of the uteri of normal cows which might be associated with definite stages of the estrous cycle. © 1951, American Dairy Science Association. All rights reserved.