冬虫夏草菌丝提取物降低二甲基亚硝胺大鼠肝硬化门静脉高压效应的组织学基础

Cordyceps mycelia extract decreases portal hypertension in rats with dimethylnitrosamine-induced liver cirrhosis:a study on its histological basis

目的:探讨冬虫夏草菌丝提取物(Cordyceps myceliaextract,CME)对二甲基亚硝胺(di methylnitrosamine,DMN)大鼠肝硬化门静脉高压的防治效应及其作用机制。方法:50只Wistar大鼠采用10μg/kg DMN腹腔注射持续4周的方法制备大鼠肝硬化模型,并取15只大鼠作为正常对照组。造模即日起CME预防组大鼠(n=15)予0.74g/(kg.d)CME灌胃(按冬虫夏草菌丝生药质量计算),1次/d,预防用药持续4周;CME治疗组大鼠(n=10)于造模成功后开始给药,用药4周。分别于造模后3d、2周、4周和造膜终止后2周、4周进行动态效应观察,肠系膜前静脉分支插管法检测门静脉压力(pressure of portal vein,Ppv);放射免疫法测定血清透明质酸(hyaluronic acid,HA)含量,免疫组织化学法检测肝窦壁CD44、第Ⅷ因子相关抗原血管假性血友病因子(von Willebrand factor,v WF)、α-平滑肌肌动蛋白(alpha-smooth muscle actin,α-SMA)、层黏连蛋白(laminin,LM)、Ⅳ型胶原(collagen typeⅣ,ColⅣ)和Ⅰ型胶原(collagen typeⅠ,ColⅠ)表达。结果:预防用药4周后,与模型组比较,CME组大鼠门静脉管径显著缩小,门静脉压力显著降低(P<0.05),血清HA含量显著下降(P<0.05),v WF、α-SMA、ColⅣ、LM、ColⅠ染色减弱(P<0.05),CD44染色增强(P<0.05)。治疗用药2周时,与模型组比较,CME组大鼠门静脉直径显著缩小,门静脉压力显著降低(P<0.05),血清HA含量显著下降(P<0.05)。治疗用药4周时CME组大鼠门静脉管径与门静脉压力恢复至同期正常对照组大鼠水平。治疗用药2、4周时,与模型组比较,CME组大鼠肝窦壁CD44染色面积增加(P<0.05),LM、α-SMA、v WF和ColⅠ染色减弱(P<0.05),肝窦壁ColⅣ染色无显著变化。结论:CME对DMN致大鼠肝硬化门静脉高压具有良好的干预和治疗作用。CME抗肝窦壁损伤、保护肝窦内皮细胞、抑制肝星状细胞活化,抑制肝窦毛细血管化形成与促进其逆转是其效应的组织学基础。

To study the effects of Cordyceps mycelia extract （CME） on portal hypertension in rats with dimethylnitrosamine （DMN） induced liver cirrhosis and probe into the mechanism of the action. Methods： A rat model of liver cirrhosis was induced by peritoneal injection of DMN （at a dose of 10 μg/kg, once a day, 3 consecutive days per week） for 4 weeks. Other 15 rats were assigned into normal control group. The rats in CME-prevented group were administrated CME 0. 74 g/（kg · d）, once a day, simultaneously with DMN treatment and kept on 4-week administrating, and the rats in CME-treated group were administrated after the model was established. After 3-day, 2- and 4-week DMN injection and 2-, 4-week after the rat liver got cirrhosis, the pressure of portal vein （Ppv） was directly measured by intubation via tributary of vena mesenterica anterior. The serum hyaluronic acid （HA） content was measured by radioimmunoassay. The expressions of CD44, von Willebrand factor （vWF）, laminin （LM）, alpha-smooth muscle actin （α-SMA）, type Ⅰ collagen （Col Ⅰ ） and type IV collagen （Col Ⅳ） proteins in the hepatic sinusoidal walls were examined by immunohistochemistry. Results： The caliber of portal vein （Cpv） and Ppv in the CEM group （after 4-week prevention） were significantly decreased as compared with those in the untreated group at the same point of time （P〈0.05）, also including serum HA content （P〈0.05）, and vWF, Col I , Col IV, LM, α-SMA positive staining （P〈 0.05）; however, CD44 positive staining were increased in the CEM group （P〈0.05）. The Cpv, Ppv and serum HA content were significantly decreased after 2-week CME treatment as compared with those in the untreated group （P〈0. 05）. After 4-week CME treatment, the Cpv and Ppv in the CEM group were recovered to the normal level. After 2- and 4-week CME treatment, vWF, Col Ⅰ , LM and α-SMA positive stainings were decreased （P〈0.05）, and CD44 positive staining was increased （P〈0.05） in the CME group as compared with those in the untreated group at the same point of time, but there were no marked changes found in Col Ⅳ staining. Conclusion： CME plays a good role in preventing and treating the portal hypertension in rats with DMN-induced liver cirrhosis. The histological bases of the effects are to treat liver sinusoidal endothelial cell injury, inhibit hepatic stellate cell activation, inhibit and reverse hepatic sinusoidal capillarization.