ARTERIOLE ALTERATION IN NORMAL AND HYPERPLASTIC ENDOMETRIUM

During estrus artificially induced by estrone a typical dilatation, increase in size of the lumen, hypertrophy of the muscular tunic, and doubling in nuclear volume of the muscle cells of the endomyometrial arterioles of rats take place. During the secretory phase in human endometrium there is a dilatation of the spiral arterioles (enlargement of both diameter and lumen) and in the premenstrual period vasoconstriction of the arterioles. In glandular hyperplasia of the endometrium, an arteriosclerotic type of alteration occurs which possibly contributes to local hemorrhage and results in irregular shedding of the endometrium and increased bleeding. © 1968.