Diabetes alters contraction-induced mitogen activated protein kinase activation in the rat soleus and plantaris.
The prescription of anaerobic exercise has recently been advocated for the management of diabetes; however exercise-induced signaling in diabetic muscle remains largely unexplored. Evidence from exercise studies in nondiabetics suggests that the extracellular-signal-regulated kinases (Erk1/2), p38, and c-JUN NH2-terminal kinase (Jnk) mitogen-activated protein kinases (MAPKs) are important regulators of muscle adaptation. Here, we compare the basal and the in situ contraction-induced phosphorylation of Erk1/2- p38- and Jnk-MAPK and their downstream targets (p90rsk and MAPKAP-K2) in the plantaris and soleus muscles of normal and obese (fa/fa) Zucker rats. Compared to lean animals, the time course and magnitude of Erk1/2, p90rsk and p38 phosphorylation to a single bout of contractile stimuli were greater in the plantaris of obese animals. Jnk phosphorylation in response to contractile stimuli was muscle-type dependent with greater increases in the plantaris than the soleus. These results suggest that diabetes alters intramuscular signaling processes in response to a contractile stimulus.
Department of Biological Sciences, Marshall University, Huntington, WV 25755, USA.
A
A
Katta
D L
DL
Preston
S K
SK
Karkala
S
S
Asano
S
S
Meduru
S P
SP
Mupparaju
E
E
Yokochi
Kevin M
KM
Rice
D H
DH
Desai
E R
ER
Blough
D000818:Animals; D003920:Diabetes Mellitus / Q000201:enzymology / Q000473:pathology*; D003921:Diabetes Mellitus, Experimental / Q000201:enzymology / Q000473:pathology*; D015971:Gene Expression Regulation, Enzymologic; D020935:MAP Kinase Signaling System; D008297:Male; D009119:Muscle Contraction; D018482:Muscle, Skeletal / Q000378:metabolism* / Q000473:pathology*; D010766:Phosphorylation; D010805:Physical Conditioning, Animal; D051381:Rats; D011924:Rats, Zucker; D015398:Signal Transduction