Effect of melittin on Na⁺, K⁺-ATPase gene expression in cultured neonatal rat myocardial cells

Purpose: To observe the effect of melittin (Mel) on the expression of Na⁺, K⁺-ATPase subunit mRNA in cultured neonatal rat myocardial cells. Methods: Na⁺, K⁺-ATPase α ₁ and β₁ isoforms mRNA level were observed with reverse transcriptase polymerase chain reaction (RT-PCR). The drugs were presented in medium for 1 h after process of cell culture. GAPDH mRNA level was used as an inner standard. Results: Mel of 0.01 mmol/L and Ouabain of 1 mmol/L increased the level of mRNA α₁from 0.47 ± O.14 (n = 5) to O.66 ± O.1O (n = 6, P<O.O5) and from O.47 ± O.14 (n = 5) to O.67 ± O.O9 (n = 6, P<0.05), respectively. In contrast, the levels of mRNA β₁ did not change significantly after administration of Mel or Ouabain in the same dose mentioned above. Conclusions: Mel increased the mRNA level of Na⁺, K⁺-ATPase α₁ isoform, but did not change that of β₁ isoform.