Stimulatory effect of prostaglandins on the production of hexosamine-containing substances by cultured fibroblasts (3) induction of hyaluronic acid synthetase by prostaglandin F2alpha.

The mechanism of the stimulatory effect of prostaglandin(PG)F2alpha on the production of hexosamine-containing substances by cultured fibroblasts was studied. Treatment of the cells with 1 microgram/ml of PGF2alpha resulted in a doubled net synthesis of acidic glycosaminoglycans during 20 hrs measured with uronic acid as index, and also resulted in 300 per cent increase of 3H-glucosamine incorporation into hexosamine-containing substances during the first 6 hrs. Fractionation of the PGF2alpha-stimulated hexosamine-containing substances with double isotope technique revealed that hyaluronic acid was the most stimulated component. Prior to the increase of hyaluronic acid, hyaluronic acid synthetase activity was found to be augmented by PGF2alpha as high as 4 times over the control. The augmentation of hyaluronic acid synthetase activity by PGF2alpha did not take place if actinomycin D was simultaneously present in the culture medium, suggesting that PGF2alpha induced the enzyme.