Chronic run training suppresses alpha-adrenergic response of rat cardiomyocytes and isovolumic left ventricle.
Chronic run training suppresses alpha-adrenergic response of rat cardiomyocytes and isovolumic left ventricle.
复制标题
慢性跑步训练抑制大鼠心肌细胞和等容左心室的α-肾上腺素能反应。
DOI：
10.1152/ajpheart.1999.277.6.h2136
复制
发表时间：
1999
期刊：
影响因子：
--
通讯作者：
Moore,RL
中科院分区：
文献类型：
--
作者：
Palmer,BM;Olsson,MC;Lynch,JM;Mace,LC;Snyder,SM;Valent,S;Moore,RL
The effects of endurance run training on α-adrenergic responsiveness of rat left ventricle (LV) were examined in cardiomyocytes and isovolumic LV. Female Sprague-Dawley rats were sedentary (Sed) or trained (Tr) for >20 wk by treadmill running. Cardiomyocyte shortening and fura 2 fluorescence ratio were recorded before and during 5-min exposure to 5 μM phenylephrine (PE) while paced at 0.5 Hz in 2 mM extracellular Ca2+concentration at 29°C. Cardiomyocyte shortening and shortening velocity increased with PE, and these effects were more pronounced in the Sed group. The rate of cytosolic Ca2+concentration removal was reduced by PE in the Sed cardiomyocytes, but was unaffected in the Tr. Isovolumic LV pressure was recorded immediately before and during 5-min perfusion with 5 μM PE during pacing at 280 beats/min and 37°C, and positive inotropy due to PE was more pronounced in the Sed than in the Tr. These data demonstrated that the effects of α-adrenergic stimulation on myocardial positive inotropy and calcium regulation were reduced in this rat model of run training at both the cellular and whole organ levels.
