FAMILIAR PSEUDOHYPERKALEMIA EXHIBITS ENHANCED ERYTHROCYTE GLYCOLYSIS ASSOCIATED WITH INCREASED NA+ AND K+ DEPENDENT ATPASE ACTIVITY

Erythrocytes were isolated from 2 patients with familial pseudohyperka lemia and 7 controls for energy metabolic studies under different cond itions. Incubation of erythrocytes from patients for up to 4 hours at 37 degrees C revealed a pathological decrease in energy charge, EC, (4 3.9%) compared to controls (24.8%) p < 0.001, which could be explained by enhanced ion pumping. Further experiments were therefore conducted with ouabain in incubation medium. The EC-sparing effect in patients' erythrocytes was substantial (18.4%) compared with 7.1% in controls p < 0.01. Glucose enrichment of incubation medium revealed an enhanced lactate production at 4 hours in erythrocytes of patients with a signi ficantly higher lactate/total nucleotide ratio, 5.4 versus 3.6 in cont rols, p < 0.001. SDS-PAGE did not reveal any gross alteration of membr ane major proteins in erythrocytes from patients. We conclude that the metabolic derangements observed on incubation of erythrocytes from pa tients with familial pseudohyperkalemia are pertaining to an enhanced leakage of potassium ions out of the cells possibly combined with an i ncreased influx of sodium ions eliciting the Na+- and K+-dependent ATP ase system to work at an enhanced rate.