Mayhew M, Renganathan M, Delbono O
Department of Physiology and Pharmacology, Wake Forest University School of Medicine, Winston-Salem, North Carolina, 27157, USA.
Biochem Biophys Res Commun. 1998 Oct 9;251(1):95-9. doi: 10.1006/bbrc.1998.9438.
The dihydropyridine receptor (DHPR) and ryanodine receptor (RYR1) are needed for excitation-contraction coupling in skeletal muscle. Previous studies from this laboratory have shown DHPR-RYR1 uncoupling in 33-month-old Fischer 344 x Brown Norway F1 (F344BNF1) rats fed ad libitum. The purpose of the present study is to determine whether caloric restriction prevents age-related impairments in skeletal muscle function and expression of DHPR and RyR1. Bundles of soleus and extensor digitorum longus (EDL) were studied from rats fed ad libitum and on 60 percent caloric restriction. Significant differences were found in peak twitch or tetanic tension between the ad libitum and calorie-restricted groups in soleus and EDL muscles. A significant increase in the expression of DHPR and RyR1 was observed in caloric restricted rats. These results show that calorie restriction preserves the mechanical properties of aging hind-limb skeletal muscle and maintains the level of DHPR and RyR1 in aged F344BNF1 rats fed ad libitum.
二氢吡啶受体（DHPR）和兰尼碱受体（RYR1）是骨骼肌兴奋-收缩偶联所必需的。本实验室先前的研究表明，随意进食的33月龄Fischer 344×Brown Norway F1（F344BNF1）大鼠存在DHPR-RYR1解偶联现象。本研究的目的是确定热量限制是否能预防骨骼肌功能以及DHPR和RyR1表达的年龄相关性损伤。对随意进食和热量限制60%的大鼠的比目鱼肌束和趾长伸肌（EDL）进行了研究。在随意进食组和热量限制组的比目鱼肌和EDL肌肉中，峰值抽搐或强直张力存在显著差异。在热量限制的大鼠中，观察到DHPR和RyR1的表达显著增加。这些结果表明，热量限制可保留衰老后肢骨骼肌的力学特性，并维持随意进食的老年F344BNF1大鼠中DHPR和RyR1的水平。
