Effects of electrical stimulation‐induced resistance exercise training on white and brown adipose tissues and plasma meteorin‐like concentration in rats

Abstract

Chronic endurance exercise training induces morphological and metabolic alterations including mitochondrial biogenesis in white adipose tissue (WAT) and brown adipose tissue (BAT) in rodents. A myokine called meteorin‐like (Metrnl) is associated with morphological and metabolic adaptation and increased in blood after acute resistance exercise. However, the effects of chronic resistance exercise training (RT), which aims to increase muscle mass and strength, on WAT and BAT are unclear. Therefore, we aimed to clarify the effects of RT on morphological and metabolic parameters in WAT and BAT and on plasma Metrnl concentrations. We applied electrical stimulation to both legs of rats as RT three times a week for 4 weeks. RT reduced adipocyte size in subcutaneous WAT but induced no changes in mitochondrial and thermogenesis proteins. In BAT, peroxisome proliferator‐activated receptor gamma coactivator‐1 alpha (PGC‐1α) protein levels and mitochondrial content markers were significantly higher in the RT group compared with the control group. A significant positive correlation was found between the expression of PGC‐1α in BAT and plasma Metrnl concentrations. These results suggest that plasma Metrnl is associated with PGC‐1α and mitochondrial biogenesis in BAT. This study describes a potential role of RT in preventing metabolic diseases via altering WAT and BAT and increasing plasma Mertnl concentrations.

Meteorin-like/Metrnl, a novel secreted protein implicated in inflammation, immunology, and metabolism: A comprehensive review of preclinical and clinical studies

“…PGC-1a4 is an exercise-induced splice isoform of PPARg coactivator 1a, where Metrnl was regarded as its downstream effector protein. A recent study reported by Amano et al (136) supported this effector pathway of PGC-1a along with Metrnl. After they applied 4-week electrical stimulation to rats' legs, which aimed to simulate chronic resistance exercise, an apparent positive correlation was found between the expression of PGC-1a in brown adipose tissues and plasma Metrnl levels.…”

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

“…Interestingly, exercise in combination with DHA was able to reverse the decreased expression observed in the DHA alone group. Exercise also induces Metrnl expression in skeletal muscle [ 16 ] and studies in exercise-performing mice have found increases in muscle Metrnl protein, serum levels and/or Metrnl mRNA [ 16 , 120 , 126 , 127 ]. However, we found no significant changes in Metrnl expression due to exercise in comparison with the DIO mice.…”

Physiological Changes and Pathological Pain Associated with Sedentary Lifestyle-Induced Body Systems Fat Accumulation and Their Modulation by Physical Exercise

“…In rats, resistance training induces a significant reduction of body weight and subcutaneous and epididymal white adipose tissue, but the brown adipose tissue is not affected by training. After training, animals showed smaller adipocytes [537].…”