THE INACTIVATION OF a-ESTRADIOL BY INBRED RATS

Abstract

Seven inbred strains of rats showe.l variations of over 500% in the amt. of subcut. injected a-estradiol which was necessary to produce estrus in 50% of the animals. The strain requiring the least a-estradiol inactivated the greatest proportion of the estrogen, whereas the strain requiring the most a-estradiol inactivated the smallest proportion of the estrogen. All other 5 strains inactivated essentially the same proportion of estrogen despite the variations in peripheral activity. These results are discussed in relation to other responses to estrogen admn.