Rapid reduction of prostaglandin 15-hydroxy dehydrogenase activity in rat tissues after treatment with protein synthesis inhibitors.

1 The capacity of rat kidneys to metabolize prostaglandins is rapidly lost when de novo protein synthesis is reduced by cycloheximide and puromycin. Enzyme activity declines to about half control values 45-75 min after a single dose of cycloheximide. Prostaglandin metabolism by the lung is also diminished. 2 These inhibitors apparently act by preventing the synthesis of new prostaglandin 15-hydroxy dehydrogenase enzyme. 3 The RNA synthesis actinomycin D has no effect on metabolism. 4 It is concluded that prostaglandin dehydrogenase is a short-lived enzyme in the cell whose replacement depends upon de novo protein (but not RNA) synthesis. The implications of this finding are discussed.