[A simple and reliable spectrophotometric method for quantification of pyridine nucleotides in serum]

Pyridine nucleotides plays an important role in the maintenance of cellular homeostasis and its disturbance also involves in many perturbance of metabolism, so a simple and reliable assay for determination of oxidized and reduced pyridine nucleotides in serum would be significantly necessary in understanding the redox status of body. A novel modified method, which is based on Nisselbam and making use of a cycling enzymatic reaction and spectrophotometric assay to measure the pyridine nucleotides in serum, showed good results. The standard curve has fine linear relationship; the recovery of added standard samples is almost perfect. Twenty-seven samples from 27 normal subjects were examined by the method. The results were: NADPH 8.385 +/- 1.516 nmol/ml, NADP+ 3.624 +/- 0.985 nmol/ml, and NADPH/NADP+ 2.3612 +/- 0.8057; no significant difference in the variables was found between the male and female. This is a sensitive, simple, reliable and easy-practicing method for oxidized and reduced pyridine nucleotides assay.