摘要
目的:探讨尾加压素Ⅱ受体(urotensinⅡreceptor,UT)在慢性低氧高二氧化碳肺动脉高压大鼠肺动脉中的动态变化及其意义。方法:对不同低氧(高二氧化碳)时间(1周、2周、4周)大鼠,放射性配基结合法检测肺动脉质膜UT结合位点,组织原位杂交测定各级肺小动脉UT及尾加压素Ⅱ(UⅡ)mRNA的表达。结果:①肺动脉平均压(mPAP)、右心室(RV)和左心室加室间隔(LV+S)的重量比:1周组(1HH)较对照组(NC)分别增高26.2%和21.6%、2周组(2HH)较1HH增高22.5%和14.1%、4HH组与2HH组间无显著差别(P>0.05)。②肺主动脉质膜UT最大结合位点(Bmax),1HH组比NC组高38.8%(P<0.01),2HH组比1HH组高23.2%(P<0.01),4HH组比2HH组高7.3%(P<0.05),随低氧时间延长有渐升的趋势;UⅡ受体亲和力(Kd值)各组间无差别。③三级肺小动脉UⅡmRNA相对含量的变化:2HH、4HH组明显高于NC组(P均<0.01);2HH组较1HH组分别高5.9%(P>0.05)、16.4%和9.1%(P均<0.01);4HH组与2HH组间无明显差异。④三级肺小动脉UT mRNA相对含量的变化:各低氧高二氧化碳组均高于NC组(P均<0.01),以1HH组后2级肺小动脉的表达最强,而4HH组与2HH组间无显著差别(P>0.05)。⑤肺小动脉显微结构的变化:4HH组各级血管均有显著重构,1HH组无明显变化,2HH组介于两者之间。结论:UT在慢性低氧高二氧化碳肺动脉高压大鼠肺动脉内的动态变化与肺动脉高压、肺血管改建的病理进程密切相关。
Aim：To investigate the dynamic changes and functions of urotensin Ⅱ （UⅡ ） receptor（UT） in pulmonary arteries of rats chronically exposed to hypoxia-hypercapnia. Methods： In rats with hypoxia-hypercapnia at 1,2 and 4 weeks UⅡ receptor binding of pulmonary arteries sarcolemma was determined by radiollgand assay. UⅡ mRNA and UTmRNA in various grades of pulmonary arterioles were measured by in situ hybridization. Results： ① Mean pulmonary pressure （mPAP） and weight ratio of right ventricle to left ventricle and septum（ RV/LV ＋ S） of 1-week group were higher than those of normal control （NC） group by 26.2 % and 21.6 % （ P〈0.01）, respectively, and 2-week group higher than 1-week group by 22.5% and 14.1% （respectively, P〈0.01）. However, no significant changes were found between 4-week and 2-week group. ②UⅡ receptor （Bmax） of 1-week group was higher than NC group by 38.8% , 2-week group higher them 1-week group by 23.2%,and 4-week group increased 7.3 % compared with 2-week group（ respectively, P 〈 0.01 ）. The UT changes were time-dependent, while the affinity to U Ⅱ （Kd） was no different among each group. ③ UⅡ mRNA in each grade of pulmonary arterioles of 2-week group and 4 week group were higher than NC group（respectively, P〈0.01）, and those of 2 week group were higher than 1-week group by 5.9%（P〉0.05）, 16.4% and 9.1%（respectively, P〈 0.01 ）, while no differences existed between 2-week group and 4 week group. ④ UT mRNA in each grade of pulmonary arterioles of all hypoxia-hypercapnia groups was higher than NC group （respectively, P〈 0.01 ）, and those of two abaxial grade vessels in 1-week group were the highest. No differences existed between 2-week group and 4-week group. ⑤The pulmonary vessels remodeling were time-dependently aggravated by hypoxia-hypercapnia. Conclusion： The dynamic changes of UT in pulmonary arterioles might have important contribution to the development of pulmonary hypertension and pulmonary arteriole remo-deling induced by chronic hypoxia-hypercapnia in rats.
出处
《中国应用生理学杂志》
CAS
CSCD
北大核心
2005年第4期377-381,共5页
Chinese Journal of Applied Physiology
基金
浙江省教育厅科研基金资助项目(20020468)
温州市科委基金资助项目(Y2003A037)
关键词
尾加压素
受体
低氧
高血压
肺性
urotensin
receptor
hypoxia
hypertension, pulmonary
