Effects of ischemic postconditioning on myocardial infarction sizes and protein kinase C expression in aged rats with post-ischemia reperfusion injury / 中华老年医学杂志

ABSTRACT

Objective To observe the effects of ischemic postconditioning (IPTC) on myocardial infarction sizes (IS) and protein kinase Cα (PKCα) expression in aged rats with post-ischemia reperfusion injury,and to explore the mechanism.Methods A total of 120 male Wistar rats were divided into aged group and adult group.The aged group was randomly divided into control group (n=12,30-min ischemia and 3-h reperfusion),5 s,10 s,30 s and 60 s IPTC groups [n= 12,each;after 30 min occlusion of left coronary artery (LCA),three cycles of 5 s,10 s,30 s,60 s reperfusion respectively followed by the same interval LCA re-occlusion were applied at the beginning of reperfusion].The IS was measured with TTC dye,and PKC expression was investigated by immunohistochemistry.Results Different IPTC intervals had different effects on IS and PKC expression,10 s and 30 s IPTC could reduce IS both in aged rats and adult rats [(55.9±6.0)% and (47.4±5.5)%],IS in 10 s IPTC group in aged rats was (48.1±5.3)%,in adult rats was (39.2±5.7) %;IS in 30 s IPTC group in aged rats was (48.8 ± 6.8) %,in adult rats was (40.2 ± 6.1 ) %.PKCα expression increased in aged and adult rats (all P<0.05).5 s IPTC could increase IS [IS in 5 s IPTC group in aged rats was (63.5±5.4)%,and PKCα expression reduced in aged rats (all P<0.05)].Conclusions IPTC has cardio-protective effect in aged rats suffering from acute myocardial injury during reperfusion,the effect of IPTC is related to reperfusion-reocclusion interval.