Stimulation of protein synthesis by raised extracellular pH in cardiac myocytes and perfused hearts.

Protein synthesis was stimulated in freshly-isolated rats cardiac myocytes by increasing the extracellular pH of Hepes-buffered Tyrode's solutions over the range pH 7.4-8.4. The maximal stimulation was about 45%. Protein synthesis in anterogradely-perfused rat hearts was stimulated by 11% by increasing the pH of the bicarbonate-containing perfusion medium from pH 7.4 to 7.8. This manoeuvre increased intracellular pH by 0.12 units. A concomitant increase in phosphocreatine concentration was observed. These findings are consistent with the hypothesis that intracellular pH may exert profound effects on tissue protein synthesis rates.