Premium
Effects of acute heat stress on skeletal muscle gene expression associated with energy metabolism in rats
Author(s) -
Sanders Sara R,
Cole Lori C,
Flann Kyle L,
Baumgard Lance H,
Rhoads Robert P
Publication year - 2009
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.23.1_supplement.598.7
Subject(s) - soleus muscle , endocrinology , medicine , gene expression , glycolysis , skeletal muscle , lactate dehydrogenase , pdk4 , oxidative stress , activator (genetics) , biology , pyruvate kinase , chemistry , metabolism , gene , biochemistry , enzyme
Study objectives were to determine the effects of acute heat stress (HS) on the expression of genes associated with energy metabolism in type I and II skeletal muscles. Male Sprague Dawley rats (n = 12; 9 mo) were randomly assigned to either thermal neutral (TN; 21.1°C) or HS conditions (39.4°C) for 6 h. Rats were anesthetized and the soleus (type I; oxidative) and tibialis anterior (TA; type II; glycolytic) muscles were collected. Total RNA was isolated and cDNA generated for real‐time PCR analysis (iQ5 Real‐Time PCR detection system). Exposure to HS tended to increase soleus and decrease TA AMP‐activated protein kinase (AMPK) mRNA abundance. Hyperthermia increased and tended to increase PPAR‐γ Co‐activator ‐1α (PGC‐1α) gene expression in soleus and TA, respectively. Pyruvate dehydrogenase kinase 4 (PDK4) mRNA abundance was increased by HS in the soleus but was unaltered in the TA. Lactate dehydrogenase‐α (LDHα) gene expression tended to increase in TA during HS but LDHα mRNA abundance did not differ in soleus between treatments. In conclusion, exposure to HS induced the differential expression of several energy metabolism genes based on muscle type (soleus versus TA). Moreover, changes in gene expression are consistent with impaired cellular energy status, perhaps due to mitochondrial dysfunction, in oxidative compared to glycolytic muscle fibers during hyperthermia.