The Role of Na^+/H^+ Exchange in Norepinephrine-induced Protein Synthesis in Neonatal Cultured Rat Cardiomyocytes : 53th Annual Scientific Session of the Japanese Circulation Society

概要

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It is reported that Na^+ influx contributes to stretch-induced cardiac hypertrophy. Na influx may also be involved in cardiac hypertrophy induced by catecholamine. In the present study, to test whether Na^+/H^+ exchange plays an important role in norepinephrine-induced cardiac hypertrophy, the effect of Na^+/H^+ exchange inhibitor, amiloride on protein systhesis was studied in cultured neonatal rat cardiomyocytes in serum free medium. [^3H]Phenylalanine uptake was determined 24 and 48 hours after administration of norepinephrine with and without amiloride. In the control, norepinephrine increased [^3H]phenylalanine uptake in a dose dependent manner (10^<-5>-10^<-7> M). Prazosin (10^<-7> M) and amiloride (10^<-5>-10^<-4>M) significantly attenuated the norepinephrine mediated protein synthesis. These results indicate that α_1-adrenergic stimulation enhances the protein synthesis through activation of Na^+/H^+ exchange. Therefore, Na^+ influx and/or PH increase may play a key role in cardiac hypertrophy.
社団法人日本循環器学会の論文
1990-05-20