DECREASED SERUM ANTIOXIDANT ACTIVITY OF HEMODIALYSIS-PATIENTS DEMONSTRATED BY METHYLGUANIDINE SYNTHESIS AND MICROSOMAL LIPID-PEROXIDATION

This study aims to raise the possibility of methylguanidine, a peroxid ative product of creatinine, as a measure of the peroxidative state. A s a known standard, we measured the inhibitory effect of uremic serum on the NADPH-dependent microsomal lipid peroxidation. This is an estab lished method for evaluating the peroxidative state and is compared to the effect of uremic serum on methylguanidine synthesis. The study sh ows decreased serum antioxidant activity in hemodialysis patients by b oth methods, though there is no correlation between them. These result s support the use of methylguanidine as a peroxidative marker and sugg est a difference in the reactive oxygen species involved in the reacti ons of methylguanidine synthesis and microsomal lipid peroxidation.