Enzyme release from isolated erythrocytes and lymphocytes in Duchenne muscular dystrophy.

The release of lactate dehydrogenase (LDH) was studied in erythrocytes and lymphocytes from patients with Duchenne muscular dystrophy. Erythrocytes were incubated in Krebs-Ringer with or without 30 mM adenosine and in autologous plasma. There was little release of enzyme in Krebs-Ringer solutions up to 24 h or in autologous plasma up to 48 h, with no statistical difference between Duchenne patients and controls. Addition of 30 mM adenosine reduced the release of LDH in Duchenne erythrocytes at 48 h from 32.4 +/- 5.66% (SE) to 6.2 +/- 1.76% (P < 0.05) and in controls from 38.1 +/- 5.93% to 23.5 +/- 4.63% (n.s.). Lymphocytes incubated in Krebs-Ringer containing 33 mM glucose released LDH faster than Duchenne patients and controls. The adenosine effect could be due to abnormal adenosine uptake (because of a generalized membrane defect) or indicate intrinsic differences in the adenine nucleotide metabolism.