长期限食对大鼠颈内动脉嘌呤受体反应性调节的影响

Effect of purinoceptor on vascular reactivity of internal carotid artery in long food-restricted rat

目的研究长期限食对大鼠颈内动脉嘌呤受体介导收缩反应以及肌性收缩反应的影响。方法限食组大鼠每天给予饮食量的50%。3周后,与对照组大鼠共同制备颈内动脉环标本,检测α,β-亚甲基ATP(α,β-MeATP)、NA和KCl诱发的血管收缩反应。结果与对照组比较,长期限食后α,β-MeATP、NA和KCl诱发的收缩反应明显增强,3种激动剂诱发的最大收缩反应分别增大了21.76%,19.42%和36.63%,而相应的EC50值在限食前后均无明显改变。结论长期限食可增强大鼠颈内动脉血管神经源性收缩,从而增强P2X1受体与α1受体介导的血管收缩功能,同时增强其肌性收缩作用,但对缩血管受体的结合率无明显影响。

Objective It is to observe the effect of long food-restriction on the constrictive responses mediated by purinoceptor,and on the muscle contractive response in rat internal carotid arteries.Methods Food-restricted rats were received approximately 50% of their daily food intake and tap water ad libitum for three weeks,and then the vasoconstrictive responses to α,β-MeATP,NA and KC1 were recorded in the isolated internal carotid arterise from both food-restricted group and control group rats.Results Compared with control group,the vasoconstriction induced by α,β-MeATP,NA and KC1 was significantly increased in food-restricted group（P 〈0.01）,the maximum vasoconstriction mediated by α,β-MeATP,NA and KCl increased by 21.76%,19.42% and 36.63% respectively.The EC50 values of them were not changed by long food-restriction in the internal carotid arteries.Conclusion In the rat internal carotid arteris,long food-restriction increases the neurogenic vasoconstriction,which is mediated by P2X1 receptors and by α1-adrenoceptors.Meanwhile the muscle contractive response is increased,but their receptor binding rates are not changed by the food-restriction.