The present study aimed to determine whether post-ischemic treatment with dexmedetomidine (DEX) protected the heart against acute myocardial ischemia/reperfusion (I/R)-induced injury in rats. The phosphatidylinositol-3 kinase/protein kinase B(PI3K/Akt)-dependent signaling pathway was also investigated. Male Sprague Dawley rats (n=64) were subjected to ligation of the left anterior descending artery (LAD), which produced ischemia for 25 min, followed by reperfusion. Following LAD ligation, rats were treated with DEX (5, 10 and 20 µg/kg) or underwent post-ischemic conditioning, which included three cycles of ischemic insult. In order to determine the role of the PI3K/Akt signaling pathway, wortmannin (Wort), a PI3K inhibitor, was used to treat a group of rats that had also been treated with DEX (20 µg/kg). Post-reperfusion, lactate dehydrogenase (LDH), cardiac troponin I (cTnI), creatine kinase isoenzymes (CK-MB), superoxide dismutase (SOD) and malondialdehyde (MDA) serum levels were measured using an ultraviolet spectrophotometer. The protein expression levels of phosphorylated (p)-Akt, Ser9-p-glycogen synthase kinase-3β (p-GSK-3β) and cleaved caspase-3 were detected in heart tissue by western blotting. The mRNA expression levels of B-cell lymphoma 2 (Bcl-2) and Bcl-2-associated X protein (Bax) were detected using reverse transcription-polymerase chain reaction. At the end of the experiment, the hearts were removed and perfused in an isolated perfusion heart apparatus with Evans blue (1%) in order to determine the non-ischemic areas. The risk and infarct areas of the heart were not dyed. As expected, I/R induced myocardial infarction, as determined by the increased serum levels of cTnI, CK-MB and MDA, and the decreased levels of SOD. Post-ischemic treatment with DEX increased the expression levels of p-Akt and p-GSK-3β, whereas caspase-3 expression was reduced following DEX treatment compared with in the I/R group. Compared with the I/R group, the ratio of Bcl-2/Bax at the mRNA level was elevated in the DEX and ischemic post-conditioning groups, whereas the expression levels of Bax were decreased. Conversely, the effects of DEX were attenuated by Wort. These results indicated that, similar to post-ischemic conditioning, post-ischemic treatment with DEX protects the heart against I/R via the PI3K/Akt-dependent signaling pathway, possibly by activating GSK-3β.

For direct detection Mie Doppler wind lidar, the method of use Fabry-Perot interferometer as a dynamic Doppler shift discriminator is proposed and investigated theoretically. For the highest measuring sensitivity part of the FPI transmission curves is utilized to measure any possible laser Doppler shift, its measuring accuracy is very high. With no loss of this significant superiority, any actual wind speed range requirement can be met by repeating this way in a measurement. The simulations for different atmosphere conditions prove that this method is more suitable for wind measurement of higher part troposphere than previous.