Abstract

Ovariectomized Long-Evans rats treated with ethinyl estradiol four hours before sacrifice showed an uptake of I¹³¹ by the uterus commensurate with this organ's increase in water content. The uptake of Na²², however, was greater than could be accounted for by the increased water content.

By intracardiac injection of I¹³¹ labeled serum albumin a remarkably large penetration of this material into the estrogen-treated uterus was shown. To prove that this increase was due to a change in capillary permeability Cr⁵¹ labeled red cells were injected into the blood stream: the distribution of the labeled blood cells indicated no appreciable difference between the vascular pool of the uterus in treated or control groups.