Petrick 2023 MiP2023

Petrick 2023 MiP2023

Age- and sex-related differences in mitochondrial ADP sensitivity in human skeletal muscle.

Link: MiP2023 Obergurgl AT

Petrick Heather L (2023)

Event: MiP2023 Obergurgl AT

Authors: Petrick Heather L, Aussieker T, Fuchs CJ, Hermans WJ, Betz MW, Pinckaers PJM, Snijders T, van Loon LJC, Holloway Graham P

Introduction: Mitochondrial ADP sensitivity represents an important control point in oxidative phosphorylation. The sensitivity of mitochondria to ADP is lower in high-lipid environments, in aging males, and in young females compared to young males. However, the interaction between sex, age, and body composition (fat mass) in the regulation of mitochondrial ADP sensitivity remains unknown.
Methods: Vastus lateralis muscle biopsies were obtained from healthy, recreationally active, young males (n=21, 24±4 y, 22.7±2.2 kg/m² BMI), young females (n=20, 21±2 y, 21.7±2.2 kg/m²), older males (n=13, 76±5 y, 25.8±2.5 kg/m²), and older females (n=6, 70±6 y, 23.4±3.0 kg/m²). Permeabilized fibers were prepared to measure mitochondrial ADP sensitivity. Whole-body DEXA scans were performed. Data (mean±SD) were analyzed using two-way ANOVAs.
Results and discussion: Body fat percentage was higher in females and older individuals (main effects). While maximal mitochondrial respiration did not differ between groups, mitochondrial ADP sensitivity was affected by sex and age. Specifically, in younger individuals mitochondrial ADP sensitivity was lower in females compared with males (~15 % higher apparent ADP Km, p=0.02). Older males also showed ~15% lower mitochondrial ADP sensitivity compared with young males (p=0.04). In contrast to young individuals, mitochondrial ADP sensitivity was numerically greater (~15 %) in older females when compared with older males (p=0.14) and younger females (p=0.12). However, there were no correlations between body fat percentage and mitochondrial apparent ADP Km in any group. We speculate that sex-based differences in mitochondrial ADP sensitivity are impacted by estrogen as opposed to body composition, as this response is lost with aging.

• O2k-Network Lab: CA Guelph Holloway GP

Affiliations

Petrick Heather L^1,2, Aussieker T¹, Fuchs CJ¹, Hermans WJ¹, Betz MW¹, Pinckaers PJM¹, Snijders T¹, van Loon LJC¹, and Holloway GP²

Dept Human Biology, Maastricht Univ, the Netherlands
Dept Human Health and Nutritional Sciences, Univ Guelph, Canada

Corresponding author: hpetrick@uoguelph.ca

Labels:

Organism: Human Tissue;cell: Skeletal muscle

Event: E2