Effects of metamizol and magnesium sulfate on enzyme activity of glucose 6-phosphate dehydrogenase from human erythrocyte in vitro and rat erythrocyte in vivo

Objective: Effects of metamizol and magnesium sulfate on erythrocyte glucos e 6-phosphate dehydrogenase enzyme activity were investigated in in vitro a nd in vivo conditions. Methods: For in vitro studies, glucose 6-phosphate dehydrogenase was purifi ed from human erythrocyte and rats were used for in vivo studies. Enzyme ac tivity was determined according to the Beutler method by using a spectropho tometer at 340 nm. Results: The results of in vitro study showed that their mean Ki values wer e 6.35 X 10(-3) M for metamizol and 1.32 X 10(-2) M for magnesium sulfate a nd their inhibition types were uncompetitive. I-50 value was 17 mM for meta mizol and 50 mM for magnesium sulfate in in vitro study. In the case of in vivo studies, 200 mg/kg metamizol inhibited the enzyme activity by 40% duri ng the first 1.5 h (p < 0.05), and 225 mg/kg magnesium sulfate significantl y inhibited the enzyme activity throughout 24 h (p < 0.01). Conclusion: The results of this study suggested that metamizol and magnesiu m sulfate have significant inhibition effect on the activity of glucose 6-p hosphate dehydrogenase enzyme in both in vivo and in vitro. (C) 2001 The Ca nadian Society of Clinical Chemists. All rights reserved.