Skeletal muscle adenosine, inosine and hypoxanthine release following ischaemic forearm exercise in myoadenylate deaminase deficiency and McArdle's disease.

Plasma adenosine, inosine and hypoxanthine concentrations were assayed in 7 controls, 5 MADD patients and 6 McArdle patients before and after ischaemic forearm exercise. The MADD patients showed a significantly lower increase in plasma inosine and hypoxanthine following exercise as compared to the controls. In the McArdle patients the increase in plasma inosine and hypoxanthine after exercise did not differ significantly from the control values. The plasma adenosine increase was very low in the three test groups and there were no significant differences.