Exercise preconditioning attenuates hind limb unloading-induced gastrocnemius muscle atrophy possibly via the HDAC4/Gadd45 axis in old rats.

Exercise preconditioning attenuates hind limb unloading-induced gastrocnemius muscle atrophy possibly via the HDAC4/Gadd45 axis in old rats. Exp Gerontol. 2019 Apr 19;: Authors: Yoshihara T, Tsuzuki T, Chang SW, Kakigi R, Sugiura T, Naito H Abstract The mechanisms involved in unloading-induced skeletal muscle loss may be age-specific, and the evidence for exercise preconditioning-induced protection against disuse muscle atrophy in aged rats is limited. Therefore, in this study, we investigated age-related differences in the activation of the HDAC4/Gadd45α pathway following hindlimb unloading (HU). We also assessed the protective effect of preconditioning exercise on this pathway in young and old rat gastrocnemius muscle. Three-month-old (young, n = 18) and 24-month-old (old, n = 18) male Wistar rats were assigned to the following groups: control group (n = 6), seven days of HU group (n = 6), and a bout of exercise preconditioning prior to HU (Ex+HU) group (n = 6). Rats of both ages in the Ex + HU group ran continuously on a motor-driven treadmill (0° slope, 20 m/min, 15 min) prior to HU. The gastrocnemius muscles were removed after 7 days of HU and analyzed for protein content and mRNA expression. Gastrocnemius muscle weight was significantly higher in the Ex+HU group than in the HU group of old rats, but not in young rats. Levels of HDAC4 protein and mRNA were significantly increased in the old HU group. ...
Source: Experimental Gerontology - Category: Geriatrics Authors: Tags: Exp Gerontol Source Type: research