The effect of verapamil on Ca2+ influx across the myocardial plasma membrane and coxsackie virus B3 ( CVB3)-RNA replication in cultured neonatal rat heart cells infected with CVB3 was investigated. It was found that t...The effect of verapamil on Ca2+ influx across the myocardial plasma membrane and coxsackie virus B3 ( CVB3)-RNA replication in cultured neonatal rat heart cells infected with CVB3 was investigated. It was found that the Ca2+ influx could be inhibited significantly (P<O. 01) by verapamil (1 μmol/L) after infection of heart cells for 48h. However, when the cultured heart cells infected with CVB3 and treated with verapamil (Iμmol/L and 10 nmo/L) at the same time for 48h, the amounts of CVB3-RNA in myocytes were significantly higher than that in infected control group (P<O. 05). These phenomena suggest that the increase of Ca2+ influx of cultured heart cells infected with CVB3 could be inhibited by some calcium antagonists, e. g. verapamil at the early stage. On the other hand, verapamil might accelerate viral replication in myocardium. Thus, although verapamil could be beneficial for decreasing the secondary Ca2+ damages and improve the myocardial electric activity, it isn’t a sensible choice for therapy in early stage of virus infection with cardiac symptoms.展开更多
Monolayer culture of spontaneously contracting rat heart cells was obtained from newborn SD rats andseeded intO culture plates. 1OOTCID50 of coxsackie virus B3 (CVB3) (Nancy strain )was added as the infectedgroup. The...Monolayer culture of spontaneously contracting rat heart cells was obtained from newborn SD rats andseeded intO culture plates. 1OOTCID50 of coxsackie virus B3 (CVB3) (Nancy strain )was added as the infectedgroup. The dynamics of taurine transport across membrane of normal heart cells and changes after infectionwere 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 cul-tured rat cardiOmyocytes,the K. of high and low affinity were 9. 5 X 10-5mol/l, and l. 3 X 1 O 2 mol/l,,respectively; (2)taurine transport across membrane was sodium-dependent with a positive linear relationshipbetween amount of taurine influx and extracellular concentration of sOdium;in addition,it was alsO regulat-ed by osmOlarity; (3) fyalanine,a carboxylic analog of taurine,could inhibit the uptake of taurine in dosedependently; (4)taurine influx was decreased in cultured rat cardiomyocytes after infected with CVB3. (5)the lnhibition ratio of taurine transport was enhanced as the infected time prolonged. This experiment pro-vides a basis fOr further investigation of kinetic test of taurine transport and more study should be carriedout to learn the effect of taurine in viral myocarditis.展开更多
文摘The effect of verapamil on Ca2+ influx across the myocardial plasma membrane and coxsackie virus B3 ( CVB3)-RNA replication in cultured neonatal rat heart cells infected with CVB3 was investigated. It was found that the Ca2+ influx could be inhibited significantly (P<O. 01) by verapamil (1 μmol/L) after infection of heart cells for 48h. However, when the cultured heart cells infected with CVB3 and treated with verapamil (Iμmol/L and 10 nmo/L) at the same time for 48h, the amounts of CVB3-RNA in myocytes were significantly higher than that in infected control group (P<O. 05). These phenomena suggest that the increase of Ca2+ influx of cultured heart cells infected with CVB3 could be inhibited by some calcium antagonists, e. g. verapamil at the early stage. On the other hand, verapamil might accelerate viral replication in myocardium. Thus, although verapamil could be beneficial for decreasing the secondary Ca2+ damages and improve the myocardial electric activity, it isn’t a sensible choice for therapy in early stage of virus infection with cardiac symptoms.
文摘Monolayer culture of spontaneously contracting rat heart cells was obtained from newborn SD rats andseeded intO culture plates. 1OOTCID50 of coxsackie virus B3 (CVB3) (Nancy strain )was added as the infectedgroup. The dynamics of taurine transport across membrane of normal heart cells and changes after infectionwere 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 cul-tured rat cardiOmyocytes,the K. of high and low affinity were 9. 5 X 10-5mol/l, and l. 3 X 1 O 2 mol/l,,respectively; (2)taurine transport across membrane was sodium-dependent with a positive linear relationshipbetween amount of taurine influx and extracellular concentration of sOdium;in addition,it was alsO regulat-ed by osmOlarity; (3) fyalanine,a carboxylic analog of taurine,could inhibit the uptake of taurine in dosedependently; (4)taurine influx was decreased in cultured rat cardiomyocytes after infected with CVB3. (5)the lnhibition ratio of taurine transport was enhanced as the infected time prolonged. This experiment pro-vides a basis fOr further investigation of kinetic test of taurine transport and more study should be carriedout to learn the effect of taurine in viral myocarditis.
