高脂饮食对大鼠动脉血管张力的影响

Effects of high fat diet on arterial tension in rats

目的 :观察高脂饮食大鼠动脉血管张力的改变及内源性 NO、PGI2 的作用。方法 :SD大鼠 1 6只分为高脂饮食组和对照组 ,喂养 5周后测定血清血脂浓度和胸主动脉环对去甲肾上腺素 (NE,1 0 - 8～ 1 0 - 4 mmol/ L)、乙酰胆碱 (ACh,1 0 - 8～ 1 0 - 4 mmol/ L)的反应。结果 :与对照组比较 ,高脂饮食组 TC、L DL 明显升高 (P<0 .0 1和 P<0 .0 5) ;胸主动脉环对 NE或 ACh的反应明显减弱 (P<0 .0 5或 P<0 .0 1 ) ;经吲哚美辛 (indomethacin,Indo)处理后 ,NE的缩血管反应恢复 ,ACh的舒血管反应无明显改变 ;Indo与 L- NNA同时处理 ,则NE的缩血管反应进一步增强 ,ACh的舒血管反应明显减弱。结论 :高脂饮食大鼠动脉血管平滑肌的收缩能力和舒张能力均下降。NO生成减少可加重血管舒张能力的下降 ,PGI2 生成减少则无此作用。

Objective:To observe the changes of arterial tension and the role of endogenous nitric oxide (NO) and prostacyclin(PGI 2)in high fat diet rats Methods:SD rats were divided into high fat diet group and normal control group After feeding 5 weeks,blood samples were collected from all of the rats for detecting serum lipoprotein,and aortas were harvested for measurement of the responses to norepinephine (NE) and acetylcholine (ACh) Result:Compared with the control group,the level of serum total cholestrol(TC),low density lipoprotein (LDL) was markedly increased in high fat diet group ( P<0 01,P <0 05,respectively) The response of NE induced vasoconstriction was significantly decreased,( P<0 01 or P <0 05),and of ACh induced relaxation was decreased too,but P >0 05 After incubated with indomethacin,the response of NE induced vasoconstriction in the aorta was enhanced,( P<0 01 or P <0 05),of ACh induced relaxation was not obviously changed When treated with N ω nitro L arginine (L NNA) simultaneously,further enhanced NE induced contraction and partially inhibited ACh induced relaxation were observed Conclusion:Both the ability of vasoconstriction and that of vasodilatation were reduced in high fat diet rats The inhibition of NO production can aggravate the decrease of vasodilatation,and the inhibition of PGI 2 production did not cause this response