Figure 3.

The effects of 6-months placebo or n3-PUFA on skeletal muscle mitochondrial function. Skeletal muscle mitochondrial function was evaluated by measuring (a) mitochondrial respiration (placebo: n = 30; n3-PUFA: n = 27), (b) ATP production (placebo: n = 20; n3-PUFA: n = 17), and (c) reactive oxygen species (ROS) generation (placebo: n = 30; n3-PUFA: n = 27) in permeabilized muscle fibers isolated from muscle biopsies of the vastus lateralis of older (65–85 years) adults before and after 6 months of placebo or n3-PUFA supplementation. (a,b) Respiration and ATP production were assessed at respiratory states 1 (baseline respiration), 2 (respiration in the presence of glutamate, malate, and succinate) and 3 (ADP-stimulated respiration through complex I + II) using an incremental, stepwise protocol. The acceptor control ratio (ACR) was calculated as the ratio of State 3:State 2 respiration. (c) ROS production was assessed during state 2 respiration. Oxygen (JO₂) and ATP (JATP) flux values were normalized to wet tissue weight and ROS generation was normalized to both wet tissue weight and to oxygen consumption at the corresponding respiratory state. Mixed repeated measures ANOVAs were performed to determine the within-subjects effects of time (baseline, follow-up), the between-subjects effects of the intervention (n3-PUFA, placebo) and the interaction between time and intervention. Significance was set a priori at p < 0.05. Individual data points represent individual participants, with blue data points representing males and black data points representing females. Bars indicate mean and standard deviation. JO₂: oxygen flux; ACR: acceptor control ratio; JATP: ATP flux; ROS: Reactive Oxygen Species.