A rapid radiometric assay for adenosine deaminase

Adenosine deaminase and purine phosphorylase activities in lymphocytes and red blood cells of patients with carcinoma of the larynx

Lymphocytes from patients with cancer of the larynx have been characterized by the activity of two enzymes involved in purine metabolism--adenosine deaminase and purine nucleoside phosphorylase. It has been shown that purine nucleoside phosphorylase activity was 1.5-fold higher in lymphocytes of patients in comparison with a group of healthy individuals. Adenosine deaminase activity in lymphocytes was elevated three to four-fold. The authors suggest that especially the estimation of adenosine deaminase activity in lymphocytes would be a useful laboratory test in the study of immune responsiveness of patients with cancer of the larynx.

A micromethod for determining adenosine deaminase and purine nucleoside phosphorylase activity in cells from human peripheral blood

A radiochromatographic method is described for measuring adenosine deaminase and purine nucleoside phosphorylase activity in cells from human peripheral blood. The respective substrates, [8-14C]adenosine or [8-14C]inosine, are converted either to inosine and hypoxanthine or hypoxanthine, respectively. A single simple and rapid chromatographic procedure is used to isolate the products of both reactions. The mean normal activity (nmol h-1mg-1) of ADA for erythrocytes is 63 +/- 24 (+/- 1 S.D.) for leukocytes, 750 +/- 280 and for lymphocytes, 2105 +/- 1170. Corresponding activities for purine nucleoside phosphorylase are 1850 +/- 490, 3665 +/- 1170 and 5890 +/- 2030. With the described methods a further patient with severe combined immuno-deficiency and adenosine deaminase deficiency has been identified.