| Background and ObjectiveIn the practice of forensic identification, some cases were often met, in which lethaltraumatic subarachnoid haemorrhage(TSAH) takes place just after slightly beaten. It's still notclear about the role that drinking playes in TSAH. Therefore, we managed to establish the TSAHmodel of rats after intragastric administration with edible alcohol; observe cerebral vessels andthoracic aorta in morphology; measure the biomechanical parameter of thoracic aorta, in order tofind out the relationship and the mechanism between drinking and TSAH, provide evidence forthe adjudgement in such cases.Materials and MethodsEstablish the TSAH model on acute alcoholism rats: 17 male SD rats were grouped atradom into fuddled group(12 rats) rats and control group(5 rats). Rats in the fuddled group wereinjected edible wine into the stomach in one time, and were hit on the head by self-made iron ofsimple pendulum two hours later. Cut off the rats's head after one hour, and take out the wholebrain and aorta and dyed by HE and collagen-elastic fiber methods. Thoracic aortas were testedby electrical muti-material tention apparatus, and stress-stain curve, failure load, elongation andelastic modulus were achieved. Distilled water was used instead of edible wine in the controlgroup. The other operation was same as the fuddled group.Establish the TSAH model on chronic alcoholism rats: 22 male rats were grouped at radominto fuddled group (17 rats) and control group(5 rats). The rats in chronic fuddled group wereintragastric administrated with edible wine twice every day with 8 hours interval for one month,8ml/kg for one time in the first two weeks and 12ml/kg in the following two weeks. The rest ofoperation was the same as the acute fuddled group. Distilled water was used instead of ediblewine in the control group. The rest of operation was the same as the fuddled group. The wholebrain and thoracic aorta were taken out and the biomechanical experiments would be doneimmediately if the rats were beaten to death in all groups.Results 1 acute fuddled groupIn acute fuddled rats, drunk behavour began to appear such as walking waggingly, lessaction, breathing fast, beating fast et al a few minutes after intragastric administration with wine.One hour later blood pressure and respiratory frequency lowered(P＜0.01), higher blood pressure(P＜0.05) and invariable respiratory frequency took up after beating the rats on the head. Incontrol group, blood pressure and respiratory rate didn't change after intragastric administrationwith distilled water, higher blood pressure and invariable respiratory frequency appeared afterhitting the rats on the head.TSAH's incidence rate is 28.6％and death rate 0 in acute group and TSAH's incidence rate anddeath rate are both 0 in control group. The acute group's concentration of ethanol in blood reachthe high-peek of 188.8±5.8mg/dl at the 2thh after injected, and then step down gradually to 1.7±0.5mg/dl at the 12th hour.The brain of acute fuddled rats is slight hydropsia and no noticeable contusion on thesurface of brain. In histology, the arachnoids were rarities, congestion.Punctiform SAH can beseen. The neuron and the microlia was slightly injured, which was mainly slightly hydropicdegeneration. The construction of the vessels are normal by HE.There is no noticeable change of thoracic aorta in acute fuddled rats in histology. The widthof the media and adventitia and media+adventitia of rats thoracic aorta in both groups are of nodifference in statistics.The stress-strain curves are achieved by one-dimensional elongateion test of thoracic aorta,the failure load is not different in statistics between the two groups, either is elongation on60KPa stress and failure load. There is no difference in statistics about the elastic modulus on30KPa stresss between the two groups.2,chronic fuddled groupThe rats in fuddled group turned out some chronic fuddled traits, such as, pur dried-up, dimand shedding, tired, eating less, malnourished, loss weight, excrement thin et al. The differencein weight becomes very obvious in statistics 4 weeks later, and blood pressure was higher at theend of the experiment and there is no change on the respiration during the experiment.TSAH's incidence rate in fuddled group is 82.4% and death rate 58.8％and both 0 incontrol group. In chronic fuddled rats's brain serious hydropsia, large SAH and no noticeable contusion were found in morphology. In histology, the arachnoids were excessive rarities andcongestion.Serious SAH can be seen. The neuron and the microlia was badly injured, which wasmainly severe hydropic degeneration and the cell nucleus pycnosis. The wall of some vessels inbrain thicken and the lumen shrinked, and vessel smooth muscle cell and collegen fiberhyperplasy. The interior elastic membrane was irregular in thickness and fractured somewhere.The intima of thoracic aorta were rarities and endothelial cell fell off irregularly. Elasticmembrane and fiber in media were twisting and irregular. The adventitia were rarities andcollegen fiber hyperplasy.Compared with control group, the media and adventitia andmedia+adventitia in fuddled rats thickened (P＜0.05).The stress-strain curves are achieved by one-dimensional elongateion test of thoracic aorta,the failure load of throacal aorta in fuddled group is lower than that in control group (P＜0.05);the elongation on 60KPa stress and failure load were lower, too (P＜0.05); the elastic moduluson 30KPa stresss in fuddled group was higher than that in control group (P＜0.05).Conclusion1,We successfully established the animal model of TSAH after acute and chronic alcoholism,and proved that drinking especially chronic alcoholism played important role in TSAH.2,The experiment proved the changes of thoracic aorta and cerebral vessels in morphology andhistology in chronic fuddled group and vessel biomechanical character, both of which might beone of most important mechanism of TSAH after drinking.3,Combining the experimental result of other member of our group and relatived reference, thefindings of no changes in vessel histology and vessel biomechanical character proved that thereare other mechanisms between TSAH and drinking.
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