FOS Protein Expression In The Medullary Visceral Zone And The Effect Of Vagus Nerve In Rats Following Experimental Subarachnoid Hemorrhage Complicated With MODS

Objective To establish a model of subarachnoid hemorrhage companied by vagotomy in rats complicated with multiple organ dysfunction syndrome (MODS);to investigate changes in tissue pathology of lung, liver, intestines and kidney;to investigate FOS protein expression in the medullary visceral zone of the rats following subarachnoid hemorrhage;To discuss the possible pathogenesis of medullary visceral zone and vagus nerve in the rats following subarachnoid hemorrhage complicated by MODS. Methods1. Subarachnoid hemorrhage was induced in rats by injecting arterial blood through the citernamagna .The vagus never was stopped in rats from subdlaphragamatic vagotomy .90 Wister rats were randomly divided into 5 groups: normal control group (n=6), sham-operative group (n=6), subdlaphragamatic vagotomy group (SDV group, n=6), subarachnoid hemorrhage group (SAH group, n=36 ) and subarachnoid hemorrhage+subdlaphragamatic vagotomy group(SAH+SDVgroup, n=36) .The SAH group and SAH+SDV group including 4h, 81, 12h, 24h, 36h, 48h, 72h seven time points.2. Changes of symptoms and signs including temperature, heart rate andrespiration of each group were recorded, the amount of WBC and function of liver and kidney were assayed. Pathological changes of lung\ liver\ intestines and kidney were recorded and pictures were taken through optical microscope.3. The area density of positive staining expressing FOSprotein were analyzed for the relative content of immunohistochemistry(ABC).4. Results were expressed as X±S. One-way-ANOVA and T-test of SPSS 10.0 soft ware was used to evaluate the difference among groups.Results1.There were no significant differences of temperature, heart rate and respiration, and the levels of WBC, ALT, AST, BUN, Cr and CK among normal control group, sham-operative group and SDVgroup(.P > 0.05).The rats of SAH group and SAH+SDV group had higher temperature, heart rate, respiration, WBC, ALTn AST, BUN > Cr and CK than the normal control group , sham-operative group and SDVgroup (P <0.01), There were significant differences of WBC, ALT, AST, BUN, Cr(/><0.05 M P<0.0\)and no significant differences of temperature, heart rate,respiration, CK between SAH group and SAH+SDV group(JP>0.05).2. After subarachnoid hemorrhage there are various inflammatory lesions on the organ tissue at every time point ,in SAH group the organ has significantly pathological changes at 24-36 hour point, the changes gradually extinct in 48 hours, and it almost recovers normal at 72 hour point;in SAH+SDV group the inflammatory reaction on lung and small intestine can be seen 4 hours after bleeding, after 12 hours nonspecific inflammatory reaction can be seen on lung, intestines > liver and kidney, the pathological changes become significant at 24-48 hour point, and there are still significantly inflammatory reaction at 72 hour.3. A few of FOS protein expressed in the medullary visceral zone of normal control group and sham-operative group.The expression of FOS protein of SDV group was more than control group and sham-operative group,but there were no significant differences among SDV group, control group and sham-operative group(P>0.05). The expression of FOS protein of SAH and SAH+SDV groups were all obviously more than control group , sham-operative group and SDV group.The FOS-like neurons of SAH group were densely expressed in the nucleus of the solitary tract, areapostren^ dorsal nucleus of vagus nerve and ventrolateral medulla.Compared with SAH group ,FOS-like neurons of SAH+SDV group were fewer and sparsely expressed in the nucleus of the solitary tract and ventrolateral medulla.FOS protein expressed in the medullary visceral zone with time progress reaching the peak at 24h, and decreased after 36-48h after subarachnoid hemorrhage.4. Incidences of systemic inflammatory response syndrome (SIRS)n MODS and mortality were respectively 100% > 69.4% and 38.9% after subarachnoid hemorrhage of SAH group, Whereas incidences of SIRS> MODS and mortality were respectively 100% > 75.0% and 47.2% after subarachnoid hemorrhage of SAH+SDV group.Conclusion1. An experimental animal model of MODS can be established successfully through subarachnoid hemorrhage was induced in rats by injecting arterial blood through the citernamagna.2. Subarachnoid hemorrhage can cause lung -> liver > intestines ■> kidney imflamming lesions and systemic inflammatory response syndrome. Systemic inflammatory response syndrome may be the Pathological bases of subarachnoidhemorrhage complicated by MODS.3. FOS protein expressd in medullary visceral zone may contribute todysfunction of autonomic nevers system after subarachnoid hemorrhage by MODS.4. Subdlaphragamatic vagotomy can add the incidences of MODS after subarachnoid hemorrhage and can aggravate the imflamming lesions of peri-organs. Vagus never can protect peri-organs potatially when subarachnoid hemorrhage complicated by MODS.