[Estrogen biosynthesis in human female adipose tissue in vitro]

The level of androstenedione aromatase activity in 10 cases of abdominal adipose tissues of premenopausal patients with benign gynecological disease (myoma uteri 7 cases, ovarian cyst 1 case, intersex 1 case, and hydatidiform mole 1 case) was examined. The adipose tissue homogenate (500mg) was incubated with [1,2,6, 7-3H]-androstenedione (10 microCi, 110 pmol), and NADPH (0.5mg) at 37 degrees C for 2h in air. After stopping the enzyme reaction, [14C]-estrone, estradiol (1 X 10(4) dpm) and cold estrone, estradiol (250 micrograms) were added as tracers. Ethyl acetate extract was submitted to Bio-Rad AG1-X2 column chromatography, TLC, and co-crystallization to constant specific activity and 3H/14C ratio. Estrone was formed in all samples (29-65 fmol/g/h), and estradiol was formed in 7 samples. The estradiol level was extremely low compared to estrone. Control samples (no tissue blank and zero time incubated samples) were under 1 fmol/g/h for estrone and estradiol through this procedure, respectively. This result indicates that adipose tissue may contribute to estrogen formation as one of the extragonadal tissues. The enzyme activity did not differ significantly according to gynecological disease, age, and superficial area.