Estrogen Receptors in Normal and Myomatous Human Uteri

The hypothesis that myomatous tissue contains more estrogen receptor than normal uterine tissue was investigated. 5 patients provided small pieces of tissue which were homogenized in a buffer immediately after hysterectomy and incubated in the presence of tritiated estradiol. Then receptors were precipitated and the receptor values from various myomas and myometrial tissue originating from different sites of human uteri were quantitated. In sum fairly equal amounts of receptors were found in myomatous and myometrial tissue from different regions of the uterus and the results compared well with those from myometrium of normal human uteri i.e. 1.9+ or -.4 pmol/gm. In contrast the number of receptors present in the endometrium was significantly greater than that in the myometrium which indicated that clear-cut differences can be detected in small samples. It is concluded that subtle variations rather than gross differences between the number of receptors are responsible for the increased sensitivity of myomatous tissue to estrogens (estradiol).