Aromatization of Androstenedione to Estrogen by Human Fetal Tissues in Vitro

The capacity of various human fetal tissues (lung, liver, stomach, small intestine and kidney) to aromatize androstenedione to estrone and estradiol was investigated. Although aromatase activity for androstenedione was observed in all fetal tissues, their conversion rates varied significantly, the highest rate of conversion being observed in the liver tissue. Estrone rather than estradiol was the major product of biosynthesis.