| Objective: With development of economy and improvement of living standards, all kinds of alcoholic drinks became popular. The phenomenon of drinking, alcohol abuse and alcohol dependence was widespread. These social problems should not be ignored. Long-term drinking promoted the occurrence of cerebrovascular disease by regulating the blood flow and vasomotor function of cerebral vessels, raising blood pressure and vascular permeability, disordering blood viscosity and coagulation and so on. But the mechanisms were not clear, and were brought to the researchers'notice in forensic medicine field, clinical medicine field and preclinical medicine field. The cases of subarachnoid hemorrhage(SAH) due to slight violence after drinking were frequently reported. It was troublesome problem to assess the relationship between drinking and SAH.Our experiment intended to establish the model of alcohol-treated rats and observe pathological changes of cerebral blood vessels in acute and chronic groups with HE stain, Weigert elastic fiber staining, transmission electron microscopy(TEM) and immunohistochemical staining, explore the mechanisms, and provide a reliable theoretical basis to assess the relationship between drinking and SAH.Methods: Sprague—Dawley(SD) rats (220g±10g) were randomly divided into following groups:control group, acute group, chronic low-dose group, chronic medium-dose group and chronic high-dose group. Rats were treated with wine of Beijing Hongxing (56%v/v) orally through blunt tipped needle, two times each day at interval of over 10 hours. Water were given orally through blunt tipped needle to adapt all rats to the process in advance. The acute group was treated with 56%v/v 1.2 mL·100g-1 dose each time and rats were respectively sacrificed after 1-day, 1-week, 2-week and 3-week treatment. The concentration and volume given to chronic groups increased gradually until the 4th week(chronic low-dose group: 56%v/v 0.4mL·100g-1 each time, chronic medium-dose group: 56%v/v 0.8mL·100g-1 each time, chronic high-dose group: 56%v/v 1.2mL·100g-1 each time), and then the full dose was supplied until the end of the 12th week. Observe behavior changes and record the weights and the systolic blood pressure using the tail-cuff method. Rats from each chronic group were respectively sacrificed after 4-week, 8-week and 12-week treatment. Water instead of wine was given to control group. Brains fixed were used for Weigert elastic fiber staining to observe the morphological changes of rat basilar artery walls. Basilar arteries dissected with stereomicroscope were observed by TEM. And expression of metrix metalloproteinase-2(MMP-2) and metrix metalloproteinase-9(MMP-9) was detected by immunohistochemical stain.Data were presented as Mean±SD and analyzed with one way ANOVA and least significant difference test(LSD) by SPSS 16.0 statistical program. A level of P<0.05 was considered statistically significant.Results:1. Behavior changes and weight changes: excitation, unsteadiness on feet, torpidity to stimulus, lethargy and debilitation came out a few minutes after treated with alcohol each time. With prolonged alcohol-treatment, rats appeared anepithymia, torpidity to stimulus, weight-decrease and so on. A significant weight lose in chronic high-dose group and chronic medium-dose group was observed at the 4th week compared to control group(P<0.05). And then significant lose in chronic low-dose group was also observed at the 12th week compared to control group(P<0.05).2. Systolic blood pressure changes: Systolic BP fluctuated smoothly in control group, but rose in each chronic group with the prolonged treatment. Systolic BP in chronic high-dose group rose most apparently, and it had increased at the 10th week significantly(P<0.05). There was also a significant increase in chronic medium-dose and low-dose groups at the 12th week(P<0.05) . 3. Pathological changes3.1 Pathological changes of liver: In acute group cellularedema of liver was observed. In chronic low-dose group, cellularedema was observed and aggravated since the 4th week, and then mild microvesicular adipose degeneration emerged. In chronic medium-dose group, there was mild microvesicular adipose degeneration, and acidophilic degeneration and inflammatory infiltration were observed later. In chronic high-dose group, the pathological changes were more serious: diffuse microvesicular adipose degeneration was obvious at the 8th week, and then multiple necrosis emerged.3.2 Pathological changes of central nervous system: In acute group, neuron edema and expansion of the space surrounding capillaries were seen. In chronic groups, there were neuron edema, disorder of cell-scatterring, karyopyknosis and nuclear condensation of neurons or purkinje cells, neuronophagia and expansion of the space surrounding capillaries.3.3 Changes of internal elastic lamina(IEL) by Weigert elastic fiber staining: There was no significant change of IEL in acute group. IEL in chronic groups had loose texture, delamination and disruption.3.4 Changes of rat basilar artery ultra-structure: The chronic hige-dose group began to appear uneven texture and unhomogeneous thickness of IEL at the 4th week. Each chronic group at the 8th week showed reduction of endothelial cell microvillus, vacuolation in or under endothelial cells(EC), uneven texture, unhomogeneous thickness, bifurcation, delamination and even fragmentation of IEL.4. Expression of MMP-2 and MMP-9: Negative expression of MMP-2 or MMP-9 was observed in walls of capillaries, small vessels or basilar arteries of control group. There were positive expression of MMP-9 in walls of capillaries and small vessels at the 1st week and 2nd week of acute treatment. Negative expression of MMP-2 was observed in capillaries or small vessels. And there were negative of MMP-2 or MMP-9 in basilar artery walls in each group. Conclusions:1. There is obvious impairment of rat cerebral vessels in medium-dose group for 8 weeks(At 1st week: 28%V/V wine, 0.4mL/100g each time; At 2nd week: 37.3%V/V wine, 0.6 mL/100g each time; At 3rd week: 56%V/V wine, 0.6 mL/100g each time; At 4th ~8th week: 56%V/V wine, 0.8mL/100g each time). These rats are ideal models to study the alcohol effect on cerebral vessels.2. Chronic alcohol treatment brings impairment in basilar artery, which makes the basilar artery fragile to external force, various stress and diseases.
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