A gender wise study of arylamine N-acetyltransferase 2 (NAT2) acetylation phenotyping using sulphamethazine by high-pressure liquid chromatography (HPLC) assay

The acetylation polymorphism is one of the most common inherited variations in the biotransformation of drugs and chemicals and large number of studies has been done to determine the distribution of acetylator phenotypes among populations of different geographic origin. The aim of this study was to investigate the acetylator phenotypes of the Pakistani population and compare it between male and female healthy volunteers. The polymorphic acetylation of sulphamethazine has been investigated in male and female volunteers (50 each) of Pakistani population. Sulphamethazine was administered orally in Capsule form as 500 mg to each healthy male and female volunteer. Sulphamethazine and acetylsulphamethazine were determined in the six hour plasma samples by high-pressure liquid chromatography (HPLC). Acetylator phenotype was determined from the metabolic ratio of acetylsulphamethazine to sulphamethazine in the plasma samples. The acetylation of sulphamethazine by arylamine N-acetyltransferase 2 (NAT2) showed bimodal population frequency distribution. 60% of the female volunteers were found to be fast and 40% to be slow acetylators while that of male volunteers were 62% fast and 38% slow acetylators.   Key words: NAT2 acetylation phenotype, sulphamethazine, male & female volunteers, HPLC assay.