Effect of propranolol on normal human erythrocytes.

The present study was undertaken to standardize the effect of propranolol on normal human red cells and thus establish certain parameters enabling us to evaluate propranolol's effect on pathological cells. Normal human erythrocytes lost 40 MEq. of potassium, decreased the intracellular pH by 0.06 units, and shifted the oxyhemoglobin dissociation curve 6.0 mm. Hg to the right in the presence of propranolol. The series of events and magnitude of the response induced by propranolol was time dependent and sensitive to temperature, pH, drug concentration, and erythrocyte concentration. Calcium was an absolute requirement for maximal propranolol action with simultaneous incorporation of trace amounts of radioactive calcium into the cell. Chelation of calcium with EDTA or EGTA inhibited the response to propranolol.