Peculiar character of dialyzate ultraviolet extinction spectra as an indicator of nucleic acid metabolism in humans

Abstract

UV extinction spectra of effluent dialyzate in the process of hemodialysis and peritoneal dialysis are studied. It is found that they have distinctive individual features unique to each patient. The shape of the spectrum remains virtually invariable for a given subject during the whole period of the study (more than a year) and does not depend on the treatment modality or other factors like sex, age, the stage of chronic renal failure, and concomitant illnesses. Absorption bands in two spectral regions--255 to 265 nm and 288 to 298 nm--account for the unique character of dialyzate spectra. Spectra classification based on the ratio of integral extinctions in these regions are introduced. It is assumed that the shape of the spectrum depends on the relative contents of plasma components. Statistical analysis of individual features of spectra for the groups of patients undergoing hemodialysis (78 people) and peritoneal dialysis (42 people) is carried out. It is revealed that the distribution of patients by the ratio of integral extinctions in the specified spectral regions adheres to the normal law. Presumably individual features of spectra could be related to uric acid and a biochemically unidentified substance with an absorption peak near 260 nm.