The Preventive Effect Of Transection Of Cervical Sympathetic Trunk On The Development Of Fibrin-induced Neurogenic Pulmonary Edema In Rats

Objective:Investigate the preventive effect of the transcection of cervical sympathetictrunk(TCST) on the development of neurogenic pulmonary edema(NPE) in rats toprovide a theoretica and effectivel basis for NPE patients in clinical.Methods:Forty-eight adult male Sqrague-Dawley rats, weighting300-350g, wererandomly divided into three groups(n=16each): control group(C group), NPEgroup(N group) and right TCST group(RT group). After the eighth-tenth day, ratsfrom N group and RT group were consecutively treated with intracisternal injectionsof fibrinogen and thrombin to build NPE modle; rats from group C are only insertedthe needle, no drugs. Record blood pressure and heart rates, measure thenoradrenaline(NE) concentration in serum, observe the level of subpleurel bleeding,and calculate lung wet/dry ratio, and make the microscopic examination of the lungsand score.Result:(1) Compared with group C, rats from group N had significantly higher of theblood pressure(BP), and lower of heart rate(HR) after intracisternal injections offibrin(P<0.05). The change of BP and HR was smaller, no significance(P<0.05);Compared with group N, rats from group RT had significantly lower of BP andhigher of HR(P<0.05).(2) Rats from C group had no NPE. Copared with C group, the incidence of NPEand lung W/D ratio of N group was significantly higher(P<0.05), but the incidence ofNPE and W/D ratio of RT group was no significance although they were stillincreased(P<0.05).(3) Rats from C group had no subpleurel bleeding, the structure of alveolar wasnormal, no oozing and bleeding; the level of the subpleurel bleeding of rats from Ngroup was significantly increased, the normal structure of clveolar had disappeared, full of effusion, and alveolar wall capillary was congestive and vasodilatory, part of asmall amount of bleeding; the changes of subpleurel bleeding and lung pathology inRT group were between C group and N group.(4) Before intracisternal injections of fibrin, there was no significance of theconcentration of norepinephrine serum among the rats from the three group(P>0.05);Compared with group C, N group NE concentration was increased significantly in theimmediate injection, up to about45times（P<0.05）；although RT group NEconcentration was still increased, the degree was smaller than N group(P<0.05).;theconcentration of both N group and RT group was decreased, but there was nosignificance in compare with the baseline.Conclusion:NPE occurs following intracisternal injections of fibrinogen and thrombin inadult rats. Right TCST can prevent the devolpment of NPE by inhibiting pronouncedactivation of sympathetic nervous system, keeping circulation stable, attenuatingbaroreflex sensitivity and improving cerebral perfusion.