Taurine influx in cultured rat cardiomyocytes and changes after CVB3 infection

Monolayer culture of spontaneously contracting rat heart cells was obtained from newborn SD rats and seeded into culture plates. 100TCID50 of coxsackie virus B3(CVB3) (Nancy strain) was added as the infected group. The dynamics of taurine transport across membrane of normal heart cells and changes after infection were examined by using radioactive isotope tracing techniques. The results demonstrated that: (1) two uptake systems of taurine with different affinities and capacities were present in the plasma membrane of cultured rat cardiomyocytes, the Km of high and low affinity were 9.5 x 10(-5) mol/L and 1.3 x 10(-2) mol/L, respectively; (2) taurine transport across membrane was sodium-dependent with a positive linear relationship between amount of taurine influx and extracellular concentration of sodium; in addition, it was also regulated by osmolarity; (3) beta-alanine, a carboxylic analog of taurine, could inhibit the uptake of taurine in dose-dependently; (4) taurine influx was decreased in cultured rat cardiomyocytes after infected with CVB3. (5) the Inhibition ratio of taurine transport was enhanced as the infected time prolonged. This experiment provides a basis for further investigation of kinetic test of taurine transport and more study should be carried out to learn the effect of taurine in viral myocarditis.