Tumor Necrosis Factor-al Pha MRNA Expression And Protection Of Lidocaine For The Lung Injury Following Intestinal Ischemia-reperfusion In Rat

Experiment I Tumor necrosls factor—alpha mRNA expression In rat lungs after Intestinal lschemla－reperfuslon objective:To observe TNF－α mRNA expression In rat lungs after intestinal lschemla－reperfuslon(I／R)．Methods:After the superior mensenteric artery(SMA)were lsolated,adult SD rats were divided into 6 groups(n＝8 each),control group(c):without occluslon of SMAï¼›lschemla group(I):with 60 min of intestinal ischemla and no reperfusionï¼›I／R group(R):4 groups according the different reperfuslon time 0．5,l,3,6 hours(R_0.5,R₁,R₃,R₆)．All the animals were hilled by exsanguinations．The lower lobes of the left lungs were obtained for TNF－α mRNA analyse by PCR and histologic evaluation．Bronchoalveolar lavage fluid(BALF)and blood protein concentrations were examined the ratio of which was lung permeability index．The TNF-α levels In serum were determined by radio－immunoassay．MAP were observed during the experiment time．Result: 1．MAP dechned guadually with prolonged reperfuslon time．2．The lung permeaballty index increased after initiating reperfusion, especially in group R₃ and ₆(P＜0．01),but no changes were observed in group I (P＞0．05)．3． After reperfusion initiated,serum TNF-α significantly increased and reached peak at 1 hour(P＜0．01)．4．Lung TNF－α mRNA expression were very low in group C and,which increased after reperrusion and maintained peak level at 1 to 3 hours (P＜0.01)．5．Pulmonary capillary bledding interstltlal edema and neutrophil infiltration, which were aggravating 3 硕士学位论文 with prolonged reperfuslon tile．Conclusion:1．TNFa was a proxxmal and early mediator In the lung Injury after intestinall／R．SerumTNF－a Increased early but transient．2．Increased expression period of lung TNF－a and its peak time were longer than In serum．Increased Lung TNF－a expression maybe an important mechanism In this kind of lung Injury． 3．Intestinall／Rcould Induce lung Injury slgnlflcantly,which characterized by Increased pulmonary mlcrovascular permeability, pulmonary caPillary bledding,Interstltlal edema and neutrophil infil上rat豆on．...