Effect of an acute long-duration exercise bout on skeletal muscle lipid droplet morphology, GLUT 4 protein, and perilipin protein expression

• Published in: European journal of applied physiology 2023-12, Vol.123 (12), p.2771-2778
• Main Authors: Bajpeyi, Sudip, Apaflo, Jehu N, Rosas, Victoria, Sepulveda-Rivera, Keisha, Varela-Ramirez, Armando, Covington, Jeffrey D, Galgani, Jose E, Ravussin, Eric
• Format: Article
• Language: English
• Subjects: Adult; Biomedical and Life Sciences; Biomedicine; Biopsy; Energy expenditure; Glucose Transporter Type 4 - metabolism; Human Physiology; Humans; Lipid Droplets - metabolism; Lipid Metabolism - physiology; Lipids; Male; Morphology; mRNA; Muscle, Skeletal - physiology; Musculoskeletal system; Occupational Medicine/Industrial Medicine; Original Article; Perilipin-1 - metabolism; Perilipin-3 - metabolism; Perilipin-5 - metabolism; Protein expression; Proteins; RNA, Messenger - metabolism; Skeletal muscle; Sports Medicine; Young Adult
• ISSN: 1439-6319; 1439-6327; 1439-6327
• DOI: 10.1007/s00421-023-05266-5

Purpose Smaller lipid droplet morphology and GLUT 4 protein expression have been associated with greater muscle oxidative capacity and glucose uptake, respectively. The main purpose of this study was to determine the effect of an acute long-duration exercise bout on skeletal muscle lipid droplet morphology, GLUT4, perilipin 3, and perilipin 5 expressions. Methods Twenty healthy men (age 24.0 ± 1.0 years, BMI 23.6 ± 0.4 kg/m 2 ) were recruited for the study. The participants were subjected to an acute bout of exercise on a cycle ergometer at 50% V O 2 max until they reached a total energy expenditure of 650 kcal. The study was conducted after an overnight fast. Vastus lateralis muscle biopsies were obtained before and immediately after exercise for immunohistochemical analysis to determine lipid, perilipin 3, perilipin 5, and GLUT4 protein contents while GLUT 4 mRNA was quantified using RT-qPCR. Results Lipid droplet size decreased whereas total intramyocellular lipid content tended to reduce ( p  = 0.07) after an acute bout of endurance exercise. The density of smaller lipid droplets in the peripheral sarcoplasmic region significantly increased (0.584 ± 0.04 to 0.638 ± 0.08 AU; p  = 0.01) while larger lipid droplets significantly decreased ( p