Relieving efefct of Dexmedetomidine on myocardial injury induced by renal ischemia-reperfusion at differ-ent time points in rats / 医学研究生学报

ABSTRACT

Objectiv e Renal ischemia-reperfusion ( I/R) may cause myocardial injury and dexmedetomidine ( DEX) is a new alpha-2 adrenergic agonist with the effects of antisympathia , seda-tion, and analgesia.This study was to investigate the effect of DEX on the myocardial tissue of rats at different time points after renal I/R. Methods Forty male Wistar rats were randomized into 5 groups of equal number,sham operation, 60 min renal ischemia and 3 h reperfusion (I/R1), 120 min ischemia and 3 h reperfusion (I/R2 ), 60 min ischemia and DEX+3 h reperfusion (D1), 120 min ischemia and DEX+3 h reperfusion ( D2) .Renal I/R was induced by removal of the right kidney and ligation of the left re-nal artery and vein followed by 3 hours of reperfusion.Meanwhile, intraperitoneal injection of DEX at 50μg/kg was given to the ani-mals in groups D1 and D2 at 60 at 120 min respectively after ischemia.After 3 hours of reperfusion, blood samples were collected for measurement of the concentrations of serum creatinine (Cr) and blood urea nitrogen (BUN), and renal and myocardial tissues harvested for observation of pathological changes under the light microscope and determination of the expressions of TNF-αand IL-10 by ELISA.Results Significant increases were observed in the concentrations of serum Cr and BUN , the expressions of TNF-αand IL-10 in the renal tissues and those in the myocardial tissues in groups I /R1([84.67 ±9.62] μmol/L, [8.55 ±1.08] mmol /L), I/R2 ([167.11 ±18.81] μmol/L, [13.42 ±1.25] mmol/L), D1 ([69.67 ±9.52] μmol/L, [7.56 ±0.70] mmol/L), and D2 ([114.29 ±12.50] μmol/L, [10.27 ±0.78] mmol/L), as compared with the sham operation group ([53.20 ±9.21] μmol/L, [3.75 ±0.78] mmol/L), (all P <0.05).Significant decreases was observed in the sham operation group as compared with other groups in the expressions of TNF-αand IL-10 (P<0.05).Significant decreases was observed in the D1 and D2 groups compared with other groups in the expressions of TNF-α, but increasing in IL-10.②Injury was reduced in the D1 and D2 groups compared with other groups.③The horizontal stripes of myocardial tissue disappeared in I/R1 and I/R2 decreases of inflammatory cells was observed in D1 and D2 groups compared with others. Conclusion Dexmedetomidine can attenuate myocar-dial injury induced by renal ischemia-reperfusion in rats and its inhibitory effect on inflammatory factors may be involved in the mechanism.