摘要
目的:观察降钙素基因相关肽(CGRP)对低氧性肺动脉高压(PAH)大鼠肺动脉胶原沉积的影响,以探讨CGRP对低氧性PAH血管重构的作用及机制。方法:大鼠适应性喂养一周,随机分为3组:常氧组、低氧组及低氧+辣椒素组。低氧诱导PAH大鼠模型。低氧+辣椒素组低氧前4 d大鼠皮下注射辣椒素(50 mg/(kg.d)),耗竭内源性CGRP。低氧(3%O2)刺激大鼠原代肺动脉平滑肌细胞(PASMCs)增殖,BrdU法检测细胞增殖。Rea-l time PCR和(或)Western blot检测CGRP、磷酸化ERK1/2(p-ERK1/2)、collagenⅠ、collagenⅢmRNA和(或)蛋白表达。结果:与常氧组相比,低氧组右心室收缩压(RVSP)、平均肺动脉压(mPAP)及肺动脉collagenⅠ、collagenⅢ和p-ERK1/2的表达明显升高,而血浆CGRP含量及肺组织CGRP的表达明显降低。HE和Masson染色结果显示低氧组大鼠肺血管中膜增厚,肺动脉胶原沉积明显增多。而用辣椒素预先耗竭内源性CGRP后能够加重低氧诱导的上述改变。同时低氧能够促进PASMCs的增殖,显著上调p-ERK1/2、collagenⅠ及collagenⅢ的表达。外源性CGRP可剂量依赖性的抑制低氧诱导的细胞增殖,明显抑制p-ERK1/2、CollagenⅠ及CollagenⅢ的表达,而CGRP的这些作用可以被CGRP阻断剂CGRP8-37所取消。结论:CGRP能够抑制低氧诱导的PAH血管重构,其机制可能与抑制ERK1/2的磷酸化,降低肺动脉胶原异常沉积有关。
Objective： To observe the effect of calcitonin gene-related peptide （CGRP） on pulmonary vascular collagen accumulation in hypoxia rats in order to study the effect of CGRP on hypoxic pulmonary vascular structural remodeling and its possible mechanism. Methods： Rats were acclimated for 1 week, and then were randomly divided into three groups： normoxia group, hypoxia group, and hypoxia plus capsaicin group. Pulmonary arterial hypertension was induced by hypoxia in rats. Hypoxia plus capsaicin group, rats were given capsaicin （50 mg/（ kg.d）, s. c） 4 days before hypoxia to deplete endogenous CGRP. Hypoxia （3 % 02） stimulated proliferation of pulmonary arterial smooth muscle cells （PASMCs） and proliferation was measured by BrdU marking. The expression levels of CGRP, phosphorylated ERK1/2 （p-ERK1/ 2）, collagen I and collagen m were detected by real-time PCR or Western blot. Results： Right ventricle systolic pressure （RVSP） and mean pulmonary arterial pssure （mPAP） of pulmonary arterial hypertension （PAH） rats induced by hypoxia were higher than those of normoxia rats. By HE and Masson staining, it was demotrated that hypoxia also significantly induced hypertrophy of pulmonary arteries and increased level of collagen accumulation. Hypoxia dramatically decred the CGRP level and increased the expression of p-ERK1/2, collagen I ,collagen m in pulmonary arteries. All these effects of hypoxia were further aggravated by pre-lreatment of rats with capsaicin. CGRP concentralion- dependently inhibited xia-induced proliferation of PASMCs, markedly decreased the expression of p-ERK1/2, collagen I and collagen Ⅲ. All these effects of CGRP were abolished in the presence of CGRPS-37. Conduslon： These results suggest that CGRP might inhibit hypoxia-induced PAH and vascular remodeling, through inhibiting phosphorylafion of ERK1/2 and alleviating the collagen accumulation of pulmonary arteries.
出处
《中国应用生理学杂志》
CAS
CSCD
2013年第2期182-186,192,共6页
Chinese Journal of Applied Physiology
基金
国家自然科学基金资助项目(30873061)
