Abstract: | Cimetidine and ranitidine interact with microsomes from human and pig liver and with purified cytochrome P-450 in the ligand-type manner. The affinity for cimetidine is about 10 times as high as that for ranitidine. Accordingly amplitudes of the specta are much higher for cimetidine. These results are in accordance with those obtained earlier with rat liver microsomes. The inhibitory potency of either compound with regard to dealkylation of 7-ethoxycoumarin appears to be less in the human preparation. |