Biogenesis of Estrogens by the Human Ovary

Although cholesterol has been accepted as a precursor of the neutral steroid hormones, its role in estrogen formation has been subject to much doubt.It was postulated, on the basis of experiments in z&o in the pregnant mare, that cholesterol was not an estrogen precursor (1).The test animal had readily converted radioactive acetate to labeled estrogens, but had failed to convert administered radioactive cholesterol.Furthermore, in the acetate experiment, the serum cholesterol was not significantly labeled.At that time, it was felt that the conversion of neutral steroids to estrogens was not an important pathway, thereby excluding a major precursor role for cholesterol as well (1).A discussion of the validity of these arguments has been published