[Protective effect of calcium channel agonist BayK8644 on lungs against ischemia-reperfusion injury in rabbits].

OBJECTIVE

To explore the protective effect of calcium channel agonist BayK8644 preconditioning on the lungs against ischemia-reperfusion injury (I/R) and its mechanism in rabbits.

METHODS

Forty rabbits were randomly divided into 4 groups (10 in each group): a sham-operated group (Sham), an I/R group (I/R), an ischemic preconditioning (IP) group (IP), and a BayK8644 preconditioning group(BayK8644).The wet to dry weight (W/D) ratio, superoxide dismutase (SOD) activity, myleoperoxidase (MPO), and malondialdehyde (MDA) contents of the lung tissues were measured after the operation. Morphological and ultrastructural changes of the lung tissue were observed by light and electron microscope. The expression of pulmonary surfactant-associated protein-A (SP-A) was examined with immunohistochemistry.

RESULTS

The W/D ratio, MPO and MDA contents of the lung tissue in the BayK8644 group and IP group were significantly lower than those in the I/R group (P<0.05), while the SOD activity and expression of SP-A of the lung tissue in the BayK8644 group and IP group were significantly higher than those in the I/R group(P<0.05), The morphological changes and ultrastructural changes were less notable in the BayK8644 group and IP group, compared with the I/R group. There was no significant difference in SOD activity, MPO and MDA contents between the BayK8644 group and IP group (P>0.05).

CONCLUSION

Appropriate BayK8644 preconditioning can induce transient Ca²+ influx, and elicit strong protection against the lung ischemia-reperfusion injury, which can simulate the endogenous protective effect of ischemic preconditioning.