Beneficial roles of nicotine on rats with splanchnic artery occlusion shock

Objective To investigate the beneficial roles of nicotine,a selective cholinergic agonist,on rats with splanchinc artery occlusion (SAO) shock.Methods Forty male anaesthetized SpragueDawley rats,which were randomly divided into 5 groups,were subjected to clamping of the splanchnic arteries for 45 min,followed by release of the clamp to recover reperfusion.This surgical procedure resulted in an irreversible state of shock (SAO shock).Sham operated animals were used as controls.All the animals were implanted with catheter into left common artery to connect pressure transducer for continuously monitoring mean aortic pressure (MAP).At 60 min after reperfusion,all animals were sacrificed for biochemical studies and histological examination.Serum level of malondialdehyde (MDA) and content of myeloperoxidase (MPO) and nitric oxide ( NO),expression of inducible nitric oxide synthase (iNOS) in ileum,and pathologic changes of ileum were examined.Results Compared with SAO shock group,the serum level of MDA,the tissue levels of MPO,NO and iNOS in the ileum were significantly decreased ( P ＜0.05 or P＜0.01 ) and the ileum injury was attenuated in the nicotine group.Administration of specific nAeh receptor antagonist worsened SAO shock-induced tissue injury,and there was no difference in concentration of serum MDA,and in contents of MPO,NO,and iNOS of ileum between two antagonist groups (P ＞ 0.05 ).Conclusion The results suggest that nicotine may play beneficial roles on SAO shock rats through activation of cholinergic anti-inflammatory pathway. Key words: Shock;  Ischemia;  Reperfusion injury;  Nicotine;  Ileum