Aim To determine the effects of glucose on APD, I_(K1) , I_K , I_(Ca-L), ofventricular myocytes in guinea pigs, Methods Whole-cell patch-clamp technique was used to record thechanged action potential ionic current ind...Aim To determine the effects of glucose on APD, I_(K1) , I_K , I_(Ca-L), ofventricular myocytes in guinea pigs, Methods Whole-cell patch-clamp technique was used to record thechanged action potential ionic current induced by glucose of single cell in guinea pig ventricularmyocytes, to compare the action of 0, 10 and 20 mmol·L^(-1) glucoses on trans-membrane ioniccurrent. Results (1) Compared with 10 mmol·L^(-1) glucose concentrations, 0 and 20 mmol·L^(-1)glucose both shortened APD of ventricular myocytes ( P < 0.05). (2) The inward components ofI_(K1) density were maximal when the glucose concentration was at 10 mmol·L^(-1) . Normalized Ⅰ -Ⅴ relationships showed that both 0 and 20 mmol·L^(-1) glucose produced a left-shift of Ⅰ - Ⅴcurve. The reverse potential changed from - 72.4 mV to - 64.6 mV. (3) Compared with 10 mmol·L^(-1),both 0 and 20 mmol·L^(-1) glucose markedly increased the I_(Ca-L) amplitude and density. TheI_(Ca-L) current density was ( - 8.035 +- 0.82) pA/pF ( n = 8) at a test potential of 10 mV when theglucose concentration was 10 mmol·L^(-1) . But its current density decreased to ( - 5.45 +- 0.67)pA/pF and ( - 6.50 +- 0.56) pA/pF when glucose concentrations were 0 and 20 mmol·L^(-1) ,respectively. (4) The current densities of I_K were (18.96+-2.86) pA/pF, (8.66 +-1.87) pA/pF, and(15.32 +- 3.12) pA/pF, at + 70 mV for 0, 10 and 20 mmol·L^(-1) glucoses, respectively. ConclusionGlucose in different concentrations has different effects on APD, I_(K1), I_K, and I_(Ca-L) ofsingle ventricular myocyte in guinea pigs. There are similar actions of 0 and 20 mmol· L^(-1)glucoses on the transmembrane ionic current of ventricular myocytes in guinea pigs.展开更多
文摘Aim To determine the effects of glucose on APD, I_(K1) , I_K , I_(Ca-L), ofventricular myocytes in guinea pigs, Methods Whole-cell patch-clamp technique was used to record thechanged action potential ionic current induced by glucose of single cell in guinea pig ventricularmyocytes, to compare the action of 0, 10 and 20 mmol·L^(-1) glucoses on trans-membrane ioniccurrent. Results (1) Compared with 10 mmol·L^(-1) glucose concentrations, 0 and 20 mmol·L^(-1)glucose both shortened APD of ventricular myocytes ( P < 0.05). (2) The inward components ofI_(K1) density were maximal when the glucose concentration was at 10 mmol·L^(-1) . Normalized Ⅰ -Ⅴ relationships showed that both 0 and 20 mmol·L^(-1) glucose produced a left-shift of Ⅰ - Ⅴcurve. The reverse potential changed from - 72.4 mV to - 64.6 mV. (3) Compared with 10 mmol·L^(-1),both 0 and 20 mmol·L^(-1) glucose markedly increased the I_(Ca-L) amplitude and density. TheI_(Ca-L) current density was ( - 8.035 +- 0.82) pA/pF ( n = 8) at a test potential of 10 mV when theglucose concentration was 10 mmol·L^(-1) . But its current density decreased to ( - 5.45 +- 0.67)pA/pF and ( - 6.50 +- 0.56) pA/pF when glucose concentrations were 0 and 20 mmol·L^(-1) ,respectively. (4) The current densities of I_K were (18.96+-2.86) pA/pF, (8.66 +-1.87) pA/pF, and(15.32 +- 3.12) pA/pF, at + 70 mV for 0, 10 and 20 mmol·L^(-1) glucoses, respectively. ConclusionGlucose in different concentrations has different effects on APD, I_(K1), I_K, and I_(Ca-L) ofsingle ventricular myocyte in guinea pigs. There are similar actions of 0 and 20 mmol· L^(-1)glucoses on the transmembrane ionic current of ventricular myocytes in guinea pigs.
