Alterations of calcium channel gene expression and function in rat ventricular myocytes infected by virus

AIM: To investigate the changes of the L-type calcium channel subunit expression and calcium currents (I_~Ca -L) in cultured rat ventricular myocytes infected by coxsackie virus B_3 (CVB_3). METHODS: Primary cultured neonatal rat ventricular myocytes were infected with CVB_3. The changes of L-type calcium channel subunits mRNA in normal and infected myocytes were measured by semi-quantitative reverse transcription-polymerase chain reaction. I_~Ca -L was recorded in two groups respectively using whole cell patch-clamp techniques. RESULTS: The expression of α_1 and β subunits of L-type calcium channel mRNA increased in the infected group compared with the normal one (4.00±0.07 vs 2.21±0.41, P0.01; 2.06±0.06 vs 1.22±0.30, P0.05). The changes of the α_2/δ subunit showed no statistical significance (4.12±0.19 vs 4.132?.27, P0.05). The average current density of I_~Ca -L significantly increased by CVB_3 infection [(-8.66±0.99) pA/pF vs (-6.97±1.75) pA/pF, P0.01], the peak current increased by 25.74% (P0.05). CONCLUSION: Both α_1 and β subunits of L-type calcium channel mRNA expression and the I_~Ca -L in neonatal rat ventricular myocytes increase after CVB_3 infection. These may be one of the cellular and molecular mechanisms of abnormal electrophysiology in viral myocarditis. [