The functions of hypothalamus, medullary visceral zone and vagus nerve in multiple organ dysfunction syndrome model induced by cerebral hemorrhage of rats

Abstract

Objective To investigate the role of the hypothalamus, medullary visceral zone (MVZ)and vagus in cerebral hemorrhage (CH) in multiple organ dysfunction syndrome (MODS) rat model.To reveal the possible regulatory mechanism of the hypothalamus-MVZ-vagus pathway in CMODS.Methods 80 Wistar rats were randomly divided into sham-operative group (n = 10), subdiaphragmatic vagotomy group (SDV, n = 10), CH group (n = 20), CH + SDV group (n = 20) and CH + vagus stimulation group (CH +SIV, n = 20).Rat CH model was made by stereotaxis injection of collagenase in caudate nucleus.Its endotoxin in serum was evaluated with a test kit.The expression of FOS in the hypothalamus and CHAT in the MVZ in the rats were examined using immunohistochemistry methods.Results Abnormality of hepatic and renal function, myocardium enzyme in CH + SDV group, CH + SIV group and CH group were more severe than those in sham-operative group and SDV group; CH + SDV group more severe than CH group.CH +SIV group were much milder than CH group.The serum endotoxin level (EU/ml) in CH group,compared with the sham-operated group, were significantly different (1.03 ± 0.25 and 0.18 ± 0.03respectively, t = 10.61, P <0.01).The expression of FOS in hypothalamus of CH + SDV group (9.3 ±2.6) were significantly higher than those in sham-operative group (2.5 ± 0.4, t = 8.17, P < 0.01) and SDV group (2.9 ±0.5, t =7.64, P <0.01), but significantly lower than those in CH group (48.6 ± 18.1,t =6.80, P<0.01); was higher in CH +SIV group than those in CH group (74.3 ±6.3 and 48.6 ± 18.1,t=4.23, P <0.01).The expression of CHAT in MVZ in CH + SDV group (138.5 ± 11.8) was significantly higher than those in sham-operative group (108.2 ±9.5, t =5.39, P <0.01) and SDV group (110.7 ±9.9, t =4.83, P <0.01), but significantly lower than those in CH group (164.4 ± 12.4, t =3.53, P <0.01); was higher in CH + SIV group than in CH group (189.4 ± 15.0 and 164.4 ± 12.4, t =3.14, P < 0.05).Conclusion Hypothalamus may be related to the nerve immunity adjustment in MODS after cerebral hemorrhage.The hypothalamus-MVZ-vagus pathway may be distinctive in CMODS.Vagus nerve may be a Bi-directional Channel of the rats following cerebral hemorrhage and MODS. Key words: Cerebral hemorrhage; Multiple organ failure; Disease models,animal; Endotoxins; Vagus nerve