α‐Adrenergic Stimulation of Glycolysis and Na⁺, K⁺‐Transport in Perfused Rat Liver

Interactions between alpha-adrenergic-induced lactate production, respiration and K+ uptake of perfused rat livers were investigated. Inhibition of mitochondrial electron transport by cyanide had no effect on K+ uptake, decreased phenylephrine-induced lactate production by 60% and suppressed extra O2 consumption by more than 90%. Ouabain did not affect alpha-adrenergic-induced respiration but inhibited K+ uptake and extra lactate production. Effects of ouabain and K+-free medium on lactate production were additive and independent of cyanide, indicating that they were mediated by extramitochondrial mechanisms. Extra ATP utilized for K+ uptake in response to phenylephrine was apparently of glycolytic rather than mitochondrial origin. We propose that alpha-adrenergic-induced lactate production is secondary to an enhanced operation of the plasma membrane (Na+,K+)-ATPase.