Diazoxide Attenuates Postresuscitation Brain Injury in a Rat Model of Asphyxial Cardiac Arrest by Opening Mitochondrial ATP-Sensitive Potassium Channels

Abstract

Objective. We investigated whether and how diazoxide can attenuate brain injury after cardiopulmonary resuscitation (CPR) by selective opening of mitochondrial ATP-sensitive potassium (mitoKATP) channels. Methods. Adult male Sprague-Dawley rats with induced cerebral ischemia (n = 10 per group) received an intraperitoneal injection of 0.1% dimethyl sulfoxide (1 mL; vehicle group), diazoxide (10 mg/kg; DZ group), or diazoxide (10 mg/kg) plus 5-hydroxydecanoate (5 mg/kg; DZ + 5-HD group) 30 min after CPR. The control group (sham group, n = 5) underwent sham operation, without cardiac arrest. Mitochondrial respiratory control rate (RCR) was determined. Brain cell apoptosis was assessed using TUNEL staining. Expression of Bcl-2, Bax, and protein kinase C epsilon (PKCε) in the cerebral cortex was determined by Western blotting and immunohistochemistry. Results. The neurological deficit scores (NDS) in the vehicle group decreased significantly at 24 h and 48 h after CPR. Diazoxide significantly improved NDS and mitochondrial RCR after CPR at both time points; 5-HD cotreatment abolished these effects. Diazoxide decreased TUNEL-positive cells following CPR, upregulated Bcl-2 and PKCε, downregulated Bax, and increased the Bcl-2/Bax ratio; 5-HD cotreatment reversed these effects. Conclusions. Diazoxide attenuates postresuscitation brain injury, protects mitochondrial function, inhibits brain cell apoptosis, and activates the PKC pathway by opening mitoKATP channels.

Mitochondrial dysfunction induces NLRP3 inflammasome activation during cerebral ischemia/reperfusion injury

“…Rats were randomly divided into six groups: the sham-operation group (sham), the sham + diazoxide group, the 6 h after reperfusion group (I/R 6 h), the I/R 6 h + diazoxide group, the 24 h after reperfusion group (I/R 24 h), and the I/R 24 h + diazoxide group. The diazoxide was treated at 10 mg/kg intraperitoneally after reperfusion immediately as the previous studies [ 11 , 12 ]. The diazoxide was dissolved in sterile 0.1 M NaOH solution, and diluted with saline to the concentration of 0.02 N NaOH solution before being used.…”

“…The transwell co-culture system was conducted as previously reported [ 11 ]: BV2 cells were cultured on the upper compartment of a two-chamber transwell system (0.4-mm pore size of polycarbonate membrane coated with poly-L-lysine; Corning, Corning, NY, USA), and PC12 or bEnd3 cells were grown on the bottom well of the chamber, cultured in DMEM/F12 medium [ 16 ].…”