[Effects of carbon monoxide inhalation on severe limb ischemia/reperfusion injury and its damages lead to shock].

ABSTRACT

OBJECTIVE: To study the protective effect of carbon monoxide (CO) inhalation on the serious limb ischemia/reperfusion (I/R) injury, and which effects caused to shock in rats. METHODS: 36 SD rats were randomly divided into I/R, I/R + CO (RC), sham operation (S) groups. I/R injury models were made by the occlusion of the femoral artery for 8 h and the reperfusion for 12 h, 10 d. Before reperfusion of 2 h, RC group started to breathe medical air containing CO (the volume fraction of CO 0.075%) continuously, until after reperfusion for 4 h, a total of inhalation 6 h. S, I/R groups exposed to air, breathe freely. Caudal artery pressures (CAP), ten days survival rate, serum lactate dehydrogenase (LDH) and creatine kinase (CK) activity, limb wet - to - dry weight ratio (W/D) and the pathologic changes of limb were observed. RESULTS: Once the reperfusion started, the CAP decreased rapidly in I/R group, and the mean reduced to(5.3259 +/- 0.3832) kPa when reperfusion for 8 h. Compared to I/R group, the CAP decreased slower and smaller in RC group, moreover, its mean reduced to (8.3300 +/- 0.4224) kPa when reperfusion for 8 h. The 10 d survival rate in I/R group was that 8 rats died all between reperfusion for 13 - 20 h. Only 1 rat died in RC group and the other 7 rats were still alive when reperfusion for 10 d. Compared to I/R group, the pathological features of the ischemic limb were significant ly improved, and the figures of W/D, serum LDH and CK value were remarkable lower in RC group (P < 0.05). CONCLUSION: Inhaling exogenous low-dose CO has a reverse regulation in the blood pressure decline caused by serious limb I/R injury in rats. And at the same time, it can effectively prevent the occurrence of shock, reduce physical damage, significantly increase the survival rate of animals.