Inhibition of 5 beta-dihydrocortisone reduction in rat liver cytosol: a rapid spectrophotometric screen for nonsteroidal anti-inflammatory drug potency.
The purified NAD(P)-linked 3 alpha-hydroxysteroid dehydrogenase of rat liver cytosol is powerfully inhibited by the nonsteroidal anti-inflammatory drugs in rank-order of their therapeutic potency. This observation has now been developed into a rapid screen for predicting the potency of these agents. The screening method requires the preparation of a rat liver cytosol and access to a recording spectrophotometer. By monitoring the NADPH-linked reduction of 5 beta-dihydrocortisone catalyzed by these cytosols in the presence of nonsteroidal anti-inflammatory drugs, a high correlation between their log IC50 values for this reaction with their recommended daily dose in humans can be obtained (r = 0.960; n = 10; p greater than 0.0001). This correlation scans four orders of magnitude and demonstrates the value of this method for screening the potency of these drugs. This method is superior to traditional predictive methods (e.g., measurement of cyclooxygenase inhibition), since this assay measures the change in absorbance of a pyridine nucleotide over 5 min and is considerably more rapid than the extraction, separation, and quantitation of prostaglandins. The method does not require enzyme purification, and the cytosol, which can be prepared in a matter of hours, can be stored at -80 degrees C and used routinely for screening purposes.
D015096:3-Hydroxysteroid Dehydrogenases / Q000037:antagonists & inhibitors; D000818:Animals; D000893:Anti-Inflammatory Agents / Q000494:pharmacology*; D003600:Cytosol / Q000378:metabolism; D004353:Drug Evaluation, Preclinical; D004355:Drug Stability; D066298:In Vitro Techniques; D008099:Liver / Q000378:metabolism*; D008297:Male; D010084:Oxidation-Reduction; D011278:Pregnanes / Q000037:antagonists & inhibitors / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains
D000893:Anti-Inflammatory Agents; D011278:Pregnanes; C045993:5-dihydrocortisone; D015096:3-Hydroxysteroid Dehydrogenases