Role of mitochondrial ATP sensitive potassium channel in dexmedetomidine-induced inhibition of subarachnoid hemorrhage-caused programmed cell death in cardiomyocytes of rats / 中华麻醉学杂志

ABSTRACT

Objective To evaluate the role of mitochondrial ATP sensitive potassium ( mito-KATP ) channel in dexmedetomidine-induced inhibition of subarachnoid hemorrhage ( SAH )-caused programmed cell death ( PCD) in cardiomyocytes of rats. Methods On hundred and twenty clean-grade healthy male Sprague-Dawley rats, aged 9-10 weeks, weighing 350-400 g, were divided into 5 groups ( n=24 each) using a random number table method: sham operation group ( group Sham ) , SAH group, SAH plus dexmedetomidine group ( group SD) , 5-HD plus SAH and dexmedetomidine group ( group HSD) and 5-HD plus SAH group ( group HS) . The rats were subjected to SAH by intracranial vascular puncture after being anesthetized with pentobarbital sodium. Dexmedetomidine 5 μg∕kg was infused for 10 min via the jugular vein starting from the time point after intracranial vascular puncture, followed by a continuous infusion of 5μg·kg-1 ·h-1 for 1 h in SD and HSD groups. 5-HD 30 mg∕kg was intraperitoneally injected at 1 h before intracranial vascular puncture in HSD and HS groups. Blood samples were collected from the abdominal aor-ta at 24 h after intracranial vascular puncture for determination of serum cardiac troponin I ( cTnI) concen-trations. The animals were then sacrificed, and myocardial specimens were collected for determination of PCD rate ( by TUNEL) , reactive oxygen species ( ROS) activity ( by DCFH-DA assay) , and expression of cleaved caspase-3, cleaved caspase-1 and interleukin-1beta ( IL-1β) ( by Western blot) . Results Com-pared with group Sham, the serum concentrations of cTnI, PCD rate and ROS activity were significantly in-creased, and the expression of cleaved caspase-3, cleaved caspase-1 and IL-1βwas up-regulated in SAH, SD, HSD and HS groups ( P<0. 05) . Compared with group SAH, the serum concentrations of cTnI, PCD rate and ROS activity were significantly decreased, and the expression of cleaved caspase-3, cleaved caspase-1 and IL-1βwas down-regulated in group SD, and the serum concentrations of cTnI, PCD rate and ROS activity were significantly increased, and the expression of cleaved caspase-3, cleaved caspase-1 and IL-1βwas up-regulated in group HS ( P<0. 05) . Compared with group SD, the serum concentrations of cT-nI, PCD rate and ROS activity were significantly increased, and the expression of cleaved caspase-3, cleaved caspase-1 and IL-1β was up-regulated in group HSD ( P<0. 05) . Compared with group HSD, the serum concentrations of cTnI, PCD rate and ROS activity were significantly increased, and the expression of cleaved caspase-3, cleaved caspase-1 and IL-1βwas up-regulated in group HS ( P<0. 05) . Conclusion mito-KATP channel is involved in dexmedetomidine-induced inhibition of PCD in cardiomyocytes of rats with SAH.