ABSTRACT
Objective To determine the changes of L-type calcium currents(I Ca-L ) of rabbit ischemic myocytes in peri-infarcted zone.Methods Rabbit AMI models were made by ligation of branches of left coronary artery. After 1 week and 2 months, single pericardial myocytes were isolated enzymatically from ischemic zone adjacent to infarcted area and the normal control cells from similar regions in normal rabbit hearts. I Ca-L were recorded by using patch clamp techniques in the whole cell configuration. Results Peak of I Ca-L density of ischemic cells from the peri-infarcted zone was significantly reduced in AMI onc week later ( 3 52 0 93 pA/pF, n=6) compared to control cells ( 5 58 1 53pA/pF,n=10), P0 05 The steady-state inactivation curves were shifted to the hyperpolarizing direction in ischemic cells,the half-maximal voltage dependence of inactivation(V 1/2 ) in ischemic cells was 25 9 7 0 mV in AMI 1W , 21 3 5 6mV in AMI 2M and 13 1 4 2mV in the control cells(compared with control group,P