Habitual Aerobic Exercise Diminishes the Effects of Sarcopenia in Senescence-Accelerated Mice Prone8 Model

Abstract

Loss of muscle mass and strength are progressing with aging. Exercise is a beneficial method to prevent physical dysfunction, and habitual exercise can improve the muscle quality. Therefore, we evaluated the effects of long-term habitual exercise’s impact on sarcopenia utilizing the senescence-accelerated mice prone8 (SAMP8) model. Notably, 27 w SAMP8 were used in this study. Mice were classified into 28 (28 w) and 44 weeks old. The 44-week group was divided into the sedentary group (44 w) and a group exercising for 16 weeks (44 w + Ex). The 44 w + Ex performed habitual exercise from 28 to 44 weeks. Additionally, grip strength tests were performed with mice aged 28 and 44 weeks. Muscles were harvested and measured muscle weight at 44 w. Gastrocnemius decreased in 44 w, but was unchanged in 44 w + Ex. There was a trend for lower muscle grip strength in the 44 w group, but there was no change in 44 w + Ex. The phosphorylation levels of Akt and p70S6K as a protein synthesis marker were decreased in 44 w. Cytochrome c oxidase subunit IV (CoxIV) mRNA and protein levels decreased in 44 w. These results suggested that long-term habitual exercise attenuates muscle mass and strength decline, possibly through maintenance of muscle protein synthesis and mitochondrial maintenance.

Changes Induced by Aging and Long-Term Exercise and/or DHA Supplementation in Muscle of Obese Female Mice

“…Other strengths are the analysis of the effects of the treatments alone or in combination with each other and the use of female mice. Most of the previous studies to date regarding sarcopenia and aging, as well as n -3 PUFA supplementation and exercise, have been carried out in male mice [ 35 , 36 , 37 ], which was one of the reasons for choosing females in this study. However, it is important to consider that some studies have reported metabolic differences between male and female mice during aging and obesity [ 140 ] and therefore the use of only female mice could also be seen as a limitation, since results could vary between sexes.…”

“…Nevertheless, few studies to date have addressed the potential beneficial effects of long-term consumption of n -3 PUFA coupled with physical exercise in the context of aging and obesity [ 31 , 32 , 33 , 34 ]. In addition, most of the studies analyzing the effects of n -3 PUFA or exercise on sarcopenia have been conducted in male mice [ 35 , 36 , 37 ]. In this respect, we have recently reported that a 16-week resistance training (RT) program (alone or in combination with Docosahexaenoic acid (DHA)) improved the lower and upper limb muscle strength and quality in overweight/obese postmenopausal women [ 38 ].…”

Mouse models of sarcopenia: classification and evaluation

“…Therefore, when SAMP8 mice are used to study sarcopenia, they are mostly used at 8 months of age and later. Many studies have used SAMP8 mice to validate the effect of exercise intervention on sarcopenia and to assess its intervention effect 65,66 . For example, Takigawa et al 65 .…”

Acute Low-Intensity Treadmill Running Upregulates the Expression of Intestinal Glucose Transporters via GLP-2 in Mice

“…Exercise has been shown to induce various physiological and biochemical changes within the body. Exercise therapy has been explored for the management of dementia, weak locomotion-associated sarcopenia, and diabetes [1][2][3][4][5][6]. Several studies have demonstrated the effects of exercise on various organs, and, more recently, its effects on the small intestine have also been reported [7,8].…”