Open AccessHigher PLIN 5 but not PLIN 3 content in isolated skeletal muscle mitochondria following acute in vivo contraction in rat hindlimb
Author(s) -
Ramos Sofhia V.,
MacPherson Rebecca E. K.,
Turnbull Patrick C.,
Bott Kirsten N.,
LeBlanc Paul,
Ward Wendy E.,
Peters Sandra J.
Publication year - 2014
Publication title -
physiological reports
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.918
H-Index - 39
ISSN - 2051-817X
DOI - 10.14814/phy2.12154
Subject(s) - skeletal muscle , contraction (grammar) , mitochondrion , endocrinology , medicine , lipolysis , chemistry , muscle contraction , lipid droplet , biology , biochemistry , adipose tissue
Abstract Contraction‐mediated lipolysis increases the association of lipid droplets and mitochondria, indicating an important role in the passage of fatty acids from lipid droplets to mitochondria in skeletal muscle. PLIN 3 and PLIN 5 are of particular interest to the lipid droplet–mitochondria interaction because PLIN 3 is able to move about within cells and PLIN 5 associates with skeletal muscle mitochondria. This study primarily investigated: 1) if PLIN 3 is detected in skeletal muscle mitochondrial fraction; and 2) if mitochondrial protein content of PLIN 3 and/or PLIN 5 changes following stimulated contraction. A secondary aim was to determine if PLIN 3 and PLIN 5 associate and whether this changes following contraction. Male Long Evans rats ( n = 21; age, 52 days; weight = 317 ± 6 g) underwent 30 min of hindlimb stimulation (10 msec impulses, 100 Hz/3 sec at 10–20 V; train duration 100 msec). Contraction induced a ~50% reduction in intramuscular lipid content measured by oil red‐O staining of red gastrocnemius muscle. Mitochondria were isolated from red gastrocnemius muscle by differential centrifugation and proteins were detected by western blotting. Mitochondrial PLIN 5 content was ~1.6‐fold higher following 30 min of contraction and PLIN 3 content was detected in the mitochondrial fraction, and unchanged following contraction. An association between PLIN 3 and PLIN 5 was observed and remained unaltered following contraction. PLIN 5 may play a role in mitochondria during lipolysis, which is consistent with a role in facilitating/regulating mitochondrial fatty acid oxidation. PLIN 3 and PLIN 5 may be working together on the lipid droplet and mitochondria during contraction‐induced lipolysis.