Protective Effects Of L-arg Combining With Selective Cerebral Perfusion Through Right Subclavian Artery On Brain In Rabbits Undergoing Deep Hypothermic Circulatory Arrest

Objective To investigate the protective effects of L-arg and antegrade selective cerebral perfusion(SCP) through right subclavian artery on brain during deep hypothermic circulatory arrest(DHCA).Methods 24 albino rabbits were divided into 3 groups randomly: group DHCA (n=8); group DHCA+SCP( n=8) and group DHCA+SCP +L-arg( n=8). Three groups were placed on cardiopulmonary bypass (CPB)according to clinical method, the anonyma and bilateral subclavian arteries of animals in group DHCA+SCP and group DHCA+SCP +L-arg were isolated. Reduced nasopharyngeal temperature (NPT) by cooling to 20-18 degree C in 45 minutes. Later animals subjected to 60 mintues of DHCA. Animals in DHCA+SCP group were continuously given SCP at 10ml/(mg.min) during DHCA, additionly, in DHCA+SCP +L-arg group were given L-arg at 0.8mg/(kg.min) based on SCP, After DHCA for 60 minutes, animals were rewarmed to 36~37 degree C (NPT) in 45 minutes. All experimental models were killed at the end of rewarming to get the brain tissue and measure its content of SOD(XO method),MDA(TBA method) and caspase-3 protein expression respectively(ELISA).Results1. The activity of SOD in the DHCA+SCP though right subclavian artery group were significantly more than that of DHCA group(p<0.05), the content of MDA were significantly less than that of DHCA group(p<0.05),and the expression of caspase-3 protein was also decreased(p<0.05).2. The activity of SOD in the DHCA+SCP though right subclavian artery +L-arg group were significantly more than that of DHCA group(p<0.01), the content of MDA were significantly less than that of DHCA group(p<0.05),and the activity of caspase-3 was also decreased(p<0.01).3 The activity of SOD in the DHCA+SCP though right subclavian artery +L-arg group were significantly more than that of DHCA+SCP though right subclavian artery group (p<0.05), there was no remarkable statistical difference of the content of MDA between group DHCA+SCP and group DHCA+SCP +L-arg, but the expression of caspase-3 protein was more lower than that of group DHCA+SCP (p<0.05).ConclusionsBoth SCP and L-arg combining with SCP had beneficial effects on brain protection during DHCA, and the method of L-arg combining with SCP has better protective effects on brain than only SCP.