首页|期刊导航|老年心脏病学杂志（英文版）|Effects of continuous intermedin infusion on blood pressure and hemodynamic function in spontaneously hypertensive rats
老年心脏病学杂志（英文版）2012，Vol.9Issue(1)：17-27,11.DOI:10.3724/SP.J.1263.2012.00017
Effects of continuous intermedin infusion on blood pressure and hemodynamic function in spontaneously hypertensive rats
Effects of continuous intermedin infusion on blood pressure and hemodynamic function in spontaneously hypertensive rats
摘要
Abstract
Objective To examine the effects of exogenously administered intermedin (IMD,adrenomedullin-2) on arterial blood pressure,cardiac function and the cardiovascular IMD receptor system in spontaneously hypertensive rats (SHRs) as well as to investigate the associated mechanisms.Methods Thirteen week-old male rats were divided in Wistar Kyoto (WKY) group (n =12),SHR group (n =12),IMD group (SHRs infused with IMD 1-47 500 ng/kg per hour,n =12),and ADM group (SHRs infused with adrenomedullin 500 ng/kg per hour,n =12).Results A two-week continuous administration of low dose IMD 1-47 via mini-osmotic pumps markedly reduced blood pressure,the maximal rates of increase and decrease of left-ventricle pressure development (LV ± dp/dtmax),left ventricular systolic pressure and heart rate in SHRs.Furthermore,IMD also inhibited protein over-expression of cardiovascular IMD receptors,myocardial Receptor Activity-Modifying Proteins (RAMP1 and RAMP2),aortic RAMP1,RAMP2,RAMP3,and calcitonin receptor-like receptor (CRLR);suppressed up-regulation of aortic RAMP1,RAMP2,RAMP3 and CRLR gene expression; and markedly elevated the mRNA abundance of myocardial atrial natriuretic peptide (ANP) and myocardial brain natriuretic peptide (BNP).Additionally,IMD 1-47 administration in SHRs increased aortic cAMP concentration and reduced myocardial cAMP concentration.Conclusion These findings support the speculation that IMD,as a cardiovascular active peptide,is involved in blood pressure reduction and cardiac function amelioration during hypertension.The mechanism underlying this effect may involve IMD binding of a receptor complex formed by RAMPs and CRLR,and consequential regulation of cAMP levels and other cardiovascular active factors,such as ANP and BNP.关键词
Intermedin/Receptor activity-modifying proteins/Calcitonin receptor-like receptor/Mini-osmotic pumps/Hemodynamic parameters/Spontaneously hypertensive ratsKey words
Intermedin/Receptor activity-modifying proteins/Calcitonin receptor-like receptor/Mini-osmotic pumps/Hemodynamic parameters/Spontaneously hypertensive rats引用本文复制引用
Ying Yuan,Xi Wang,Qiang Zeng,Hong-Mei Wu,Yong-Fen Qi,Chao-Shu Tang..Effects of continuous intermedin infusion on blood pressure and hemodynamic function in spontaneously hypertensive rats[J].老年心脏病学杂志（英文版）,2012,9(1):17-27,11.基金项目
This work was supported by the National Natural Sciences Foundation of China (Grant No.30570738),the Program for New Century Excellent Talents in University of the Education Ministry of China (NCET-05-0016).The authors declare that they have no competing interests. （Grant No.30570738）
