Effect of dexmedetomidine pretreatment on a rat model of myocardial ischemia-reperfusion injury

摘要

Purpose: To study the effect of dexmedetomidine pretreatment on a rat model of myocardial ischemia-reperfusion injury (IRI) Methods: Three groups of SD rats (n = 48; mean body weight = 275 ± 25 g) were used (16 rats each): sham, IRI, and dexmedetomidine groups. Ischemia-reperfusion injury (IRI) was established via ligation of left anterior coronary artery. Rats in dexmedetomidine group were treated with single i.p. injection of dexmedetomidine (100 μg/kg) 30 min before induction of IRI. Serum levels of IL-1β, IL-6 and TNF-α were determined by enzyme-linked immunosorbent assay (ELISA). Western blotting was used to determine the protein ex pressions of bcl-2 and bax, while histopathological changes in rat myocardial tissue were determined with H&E staining. Results: Serum TNF-α, IL-1β and IL-6 levels were significantly up-regulated in IRI rats, relative to sham rats, but were decreased by dexmedetomidine (p 0.05). Dexmedetomidine significantly reduced the level of malondialdehyde (MDA) in myocardial tissues of IRI rats, but it increased superoxide dismutase (SOD) activity (p 0.05). It also markedly increased bcl-2 protein level, while the protein ex pression of bax was decreased (p 0.05). Results of H & E staining showed that dexmedetomidine significantly mitigated IRI-induced damage. Conclusion: Dexmedetomidine mitigates myocardial IRI in rats through suppression of inflammatory and apoptotic changes, and enhancement of physiological antioxidant potential. This finding may be useful for the management of myocardial ischemia-reperfusion injury.