Crandall D L, Lai F M, Huggins F J, Tanikella T K, Cervoni P
Am J Physiol. 1983 Mar;244(3):H444-8. doi: 10.1152/ajpheart.1983.244.3.H444.
The effect of a 21-day program of caloric restriction on cardiac reactivity and beta-adrenoceptor number was investigated in male Sprague-Dawley rats. Rats on the restricted diet (Restricted) exhibited significant decreases in body weight, epididymal fat pad, and retroperitoneal fat pad weight as well as the percent of body fat represented by these adipose tissue depots when compared with rats fed ad libitum (Fed). Fed rats exhibited significantly increased total heart weight and total heart protein, but the percent cardiac protein and ratio of heart weight to body weight were similar in Fed and Restricted rats. Isolated atria from Fed and Restricted rats developed similar chronotropic and inotropic responses over a range of isoproterenol concentrations. Although total beta-adrenoceptor number (fmol/heart) was greater in Fed rats, the concentration of beta-adrenoceptors (fmol/mg protein) was remarkably similar regardless of the dietary regimen. Therefore, despite significant decreases in body weight, body fat, and heart weight, the myocardium of Restricted rats maintained the capability of responding to isoproterenol as that of Fed rats, the mechanism of which is at least partially mediated through maintenance of beta-adrenoceptor concentration.
在雄性斯普拉格-道利大鼠中研究了为期21天的热量限制方案对心脏反应性和β-肾上腺素能受体数量的影响。与自由进食的大鼠（Fed）相比，限制饮食的大鼠（Restricted）体重、附睾脂肪垫、腹膜后脂肪垫重量以及这些脂肪组织库所代表的体脂百分比均显著降低。Fed大鼠的全心重量和总心脏蛋白显著增加，但Fed大鼠和Restricted大鼠的心脏蛋白百分比以及心脏重量与体重之比相似。在一系列异丙肾上腺素浓度范围内，来自Fed大鼠和Restricted大鼠的离体心房产生了相似的变时性和变力性反应。尽管Fed大鼠的总β-肾上腺素能受体数量（fmol/心脏）更多，但无论饮食方案如何，β-肾上腺素能受体浓度（fmol/mg蛋白）都非常相似。因此，尽管Restricted大鼠的体重、体脂和心脏重量显著降低，但其心肌对异丙肾上腺素的反应能力与Fed大鼠保持一致，其机制至少部分是通过维持β-肾上腺素能受体浓度来介导的。
