Effect of acute intoxication with some heavy metals on drug metabolism

In experiments on male albino rats after subcutaneous injection of a single toxic dose it was found that copper sulphate (CuSO4), cobaltous nitrate (Co(NO3)2, cadmium sulphate (CdSO4), lead acetate Pb(CH3COO)2 significantly inhibited the hexobarbital-oxidazing enzyme system, while with Nickel sulphate (NiSO4), Zinc sulphate (ZnSO4), Arsenic trioxide (As2O3), Mercuric chloride (HgCl2), Bismuth [Bi(NO3)2] and stannous chloride (SnCl2) the differences were insignificant. Aniline hydroxilase was significantly inhibited by CuSO4, Co(NO3)2, CdSO4, Pb(CH3COO)2, NiSO4, and As2O3 and not inhibited at all by HgCl2. Bi(NO3)2, SnCl2, and ZnSO4. In determination of ethylmorphine demethylase activity CuSO4, Co(NO3)2, CdSO4, and NiSO4 significantly inhibited the enzyme activity, while with the other salts the differences were insignificant. The metals which exerted an inhibitory effect on the above-mentioned enzymes reduced also the microsomal cytochrome P-450 content.