Is an increase of deoxyribonucleases activity in uraemic lymphocytes caused by their augmented synthesis in these...

Deoxyribonucleases activity in T and B lymphocytes isolated from 45 patients with chronic renal failure and 30 control subjects was measured. The results obtained clearly show a dramatic increase in enzyme activity in both T and B lymphocyte cells isolated from uraemic patients when compared with the control cell. The increase in enzyme activity was limited to the group of relatively small nucleases ranging from 14 kDa to 18 kDa. Since it was shown previously that these nucleases are among the cleavage products of the largest subunit of DNA-dependent RNA polymerase class I, it is suggested that a characteristic feature of the lymphocyte cell isolated from uraemic patients is increase of RNA polymerase lability, thus resulting in RNA synthesis decrease. Amongst toxins increasing catabolism of the active polymerase enzyme, a significant correlation with the vise of lymphocyte Mg2+ and Mn2+ ions was disclosed.