渗透压对大鼠心室肌细胞L型Ca^(2+)电流的影响

Effect of osmotic changes on L-type calcium channel currents in isolated ventricular myocytes

目的 :观察细胞胞外渗透压的改变对大鼠心室肌 L型 Ca2 +(ICa,L)电流的影响。方法 :采用全细胞膜片钳技术记录大鼠心室肌细胞 ICa,L。结果 :细胞外的渗透压由 3 10 m Osm / kg H2 O降低至 2 2 0 m Osm/ kg H2 O可使 ICa,L的 rundown明显变慢 ,电流大小无统计学意义上的差异 ;而当其中细胞外的渗透压由 3 10 m Osm/ kg H2 O升高至 410m Osm/ kg H2 O时可使 ICa,L减小 (5 1.4± 7.9) % (n=4,P<0 .0 1)。结论 :细胞外渗透压变化对大鼠心室肌基础 ICa。

AIM: To investigate the effect of osmotic changes on the L type calcium channel currents in isolated ventricular myocytes. METHODS: L type Ca 2+ current was recorded using the whole cell voltage clamp technique. RESULTS: Lowering osmolarity to 220 mOsm/kg H 2O did not significantly increased the amplitude of the I Ca,L , but the run down of the current was slow. Hyperotonic solution (410 mOsm/kg H 2O) reduced I Ca,L amplitude (51.4±7.9)% ( n =4, P <0 01). CONCLUSION: These results indicate that the changes in osmolarity of rat ventricular myocytes can modulate the function of L type calcium channel.