Age-associated alternations in cardiac β-adrenergic receptor signaling  

作　　者：Jing MA, Shiwen WANG, Ruiping XIAO The Institute of Molecular Medicine & the Institute of Cardiovascular Science, Peking University, Beijing 100871, China The Institute of Geriatric Cardiology, Chinese PLA General Hospital, Beijing 100853, China Laboratory of Cardiovascular Science, Gerontology Research Center, National Institute on Aging, Baltimore, MD 21224, USA 

出　　处：《Journal of Geriatric Cardiology》2005年第4期254-257,共4页老年心脏病学杂志（英文版）

摘　　要：During aging, cardiac contractile response to β-AR stimulation is decreased in humans and animal models. Recent studies demonstrate that the positive inotropic effects of both β1-AR and β2-AR stimulation are significantly decreased with aging.This is accompanied by decreases in both β-AR subtype densities and a reduction in membrane adenylyl cyclase activity. However,neither G protein-coupled receptor kinases (GRKs) nor inhibitory G proteins (Gi) appears to contribute to the age-associated reduction in the β-AR modulation of contraction. Thus, while both aging and chronic heart failure exhibit a diminution in cardiac β-AR responsiveness, only heart failure exhibits increased GRK-mediated desensitization ofβ-Ars and an upregulation of Gi proteins.During aging, cardiac contractile response toβ-AR stimulation is decreased in humans and animal models. Recent studies demonstrate that the positive inotropic effects of bothβ1-AR andβ2-AR stimulation are significantly decreased with aging. This is accompanied by decreases in bothβ-AR subtype densities and a reduction in membrane adenylyl cyclase activity. However, neither G protein-coupled receptor kinases (GRKs) nor inhibitory G proteins (Gi) appears to contribute to the age-associated reduction in theβ-AR modulation of contraction. Thus, while both aging and chronic heart failure exhibit a diminution in cardiacβ-AR responsiveness, only heart failure exhibits increased GRK-mediated desensitization ofβ-ARs and an upregulation of Gi proteins.

关 键 词：NATURE adrenergic receptor signaling Age-associated alternations in cardiac 

分 类 号：R541.6[医药卫生—心血管疾病]