Effect of enhanced external counterpulsation on serum nitric oxide system in a dog model of cardiac arrest

Abstract

Objective To investigate the effects of enhanced external counterpulsation (EECP) on nitric oxide system in serum in a dog model of cardiac arrest and return of spontaneous circulation(CA-ROSC). Methods Animal models of CA were inducedindogs with alternating current. After ROSC by cardiopulmonary resuscitation (CPR), 16 dogs were randomized to either the EECP or control group (n=8 per group) in accordance with the random number table. Each dog of EECP group accepted 3-h EECP from ROSC 1/4h. Venous serum was separatedat baseline before CA, at ROSC 1/4h, ROSC 4h, and ROSC 96h, respectively. The serum concentrations of endothelial nitric oxide synthase (eNOS), neuronal nitric oxide synthase (nNOS), inducible nitric oxide synthase (iNOS) and nitric oxide (NO) of each dogs were measured by using enzyme linked immunosorbent assay (ELISA ). Results There was no significant difference in baselinevalues, those of CA modelestablished, serum nNOS between two groups (P>0.05). The mean values of serum NO and eNOSin the EECP groupwere higher than those in the control group at the two points of ROSC4h, 96h (P<0.05 or P<0.01). The mean values of serum iNOS in the EECP groupwerelower than those in the control group at the two points of ROSC4h, 96h (P<0.05). Conclusion EECP can increaseserum NO levelof CA-ROSC dogs, underlying mechanism of which relates to upregulation of serum eNOS and downregulation of serum iNOS. Therefore, EECP can ease the damage ofCA model. Key words: Enhanced external counterpulsation; Cardiac arrest; nitric oxide; endothelial nitric oxide synthase; inducible nitric oxide synthase