Radioimmunological study of rat uterine extract.

A radioassay was used to demonstrate the high affinitiy of a crude rat uterine extract for tritiated estradiol-17B. Although no other chemical procedures were employed to further characterize the extract, it may contain the estrogen binding protein isolated by others. The isolate was antigenic in rabbits and administration of immune serum to female rats significantly lowered the in vitro retention of tritiated estradiol-17B in the rat uterus. It is thought that this immune serum could be successfully used to study the estrogen binding activity of rat uterus.