[2-component inhibition of prostaglandin H synthetase by nonsteroidal anti-inflammatory preparations]

A combined effect on the irreversible inhibitor aspirin and fast reversible inhibitors ibuprofen, naproxen and sodium salicylate on prostaglandin-H-synthetase was studied on microsomal fractions from ram vesicular glands. The fast reversible inhibitors were shown to bind to prostaglandin-H-synthetase at the same site as aspirin and thereby to protect the enzyme against irreversible inactivation by aspirin.