Effects of nicotine or electric vagal stimulation on injury to the transplanted lungs in rats

Objective To evaluate the effects of nicotine or electric vagal stimulation on injury to transplanted lungs in rats.Methods Twenty-four male Wistar rats with transplanted lung,weighing 250-300 g,were randomly divided into 3 groups (n =8 each) using a random number table:control group (group C),nicotine group (group NI) and electric vagal stimulation group (group VS).Nicotine 2 mg/kgwas injected intraperitoneally at 15 min after lung transplantation in group NI.Right cervical vagus nerve trank was stimulated for 20 min with continuous electric rectangular pulses (5 V,2 ms,1 Hz) at 10 min interval twice in total starting from 15 min after lung transplantation in group VS.Arterial blood samples were then collected for blood gas analysis at 15,30,45,75,105 and 135 min after lung transplantation.Arterial blood samples were then collected at 135 min after lung transplantation for determination of the plasma concentration of interleukin-6 (IL-6),IL-8 and tumor necrosis factor-α (TNF-α) by ELISA.The rats were sacrificed at 135 min after lung transplantation and the tissue of transplanted lung was removed for determination of lung injury score (LIS) according to the pathological changes obtained with light microscope,and of wet/dry lung weight ratio (W/D ratio).Results Compared with group C,PaO2 and pH value were significantly increased,and LIS,W/D ratio,and the concentrations of plasma IL-6,IL-8 and TNF-α were decreased in NI and VS groups.Conclusion Nicotine or electric vagal stimulation can attenuate injury to transplanted lungs in rats. Key words: Lung transplantation ;  Vagus nerve ;  Electric stimulation;  Cholinergic agonists