TY - JOUR
T1 - Expression and activity of cyclooxygenase isoforms in skeletal muscles and myocardium of humans and rodents
AU - Testa, Marco
AU - Rocca, Bianca
AU - Spath, Lucia
AU - Ranelletti, Franco O.
AU - Petrucci, Giovanna
AU - Ciabattoni, Giovanni
AU - Naro, Fabio
AU - Schiaffino, Stefano
AU - Volpe, Massimo
AU - Reggiani, Carlo
PY - 2007/10
Y1 - 2007/10
N2 - Conflicting data have been reported on cyclooxygenase (COX)-1 and COX-2 expression and activity in striated muscles, including skeletal muscles and myocardium, in particular it is still unclear whether muscle cells are able to produce prostaglandins (PGs). We characterized the expression and enzymatic activity of COX-1 and COX-2 in the skeletal muscles and in the myocardium of mice, rats and humans. By RT-PCR, COX-1 and COX-2 mRNAs were observed in homogenates of mouse and rat hearts, and in different types of skeletal muscles from all different species. By Western blotting, COX-1 and -2 proteins were detected in skeletal muscles and hearts from rodents, as well as in skeletal muscles from humans. Immunoperoxidase stains showed that COX-1 and -2 were diffusely expressed in the myocytes of different muscles and in the myocardiocytes from all different species. In the presence of arachidonic acid, which is the COX enzymatic substrate, isolated skeletal muscle and heart samples from rodents released predominantly PGE2. The biosynthesis of PGE2 was reduced between 50 and 80% (P <0.05 vs. vehicle) in the presence of either COX-1- or COX-2-selective blockers, demonstrating that both isoforms are enzymatically active. Exogenous PGE2 added to isolated skeletal muscle preparations from rodents did not affect contraction, whereas it significantly fastened relaxation of a slow type muscle, such as soleus. In conclusion, COX-1 and COX-2 are expressed and enzymatically active in myocytes of skeletal muscles and hearts of rodents and humans. PGE2 appears to be the main product of COX activity in striated muscles.
AB - Conflicting data have been reported on cyclooxygenase (COX)-1 and COX-2 expression and activity in striated muscles, including skeletal muscles and myocardium, in particular it is still unclear whether muscle cells are able to produce prostaglandins (PGs). We characterized the expression and enzymatic activity of COX-1 and COX-2 in the skeletal muscles and in the myocardium of mice, rats and humans. By RT-PCR, COX-1 and COX-2 mRNAs were observed in homogenates of mouse and rat hearts, and in different types of skeletal muscles from all different species. By Western blotting, COX-1 and -2 proteins were detected in skeletal muscles and hearts from rodents, as well as in skeletal muscles from humans. Immunoperoxidase stains showed that COX-1 and -2 were diffusely expressed in the myocytes of different muscles and in the myocardiocytes from all different species. In the presence of arachidonic acid, which is the COX enzymatic substrate, isolated skeletal muscle and heart samples from rodents released predominantly PGE2. The biosynthesis of PGE2 was reduced between 50 and 80% (P <0.05 vs. vehicle) in the presence of either COX-1- or COX-2-selective blockers, demonstrating that both isoforms are enzymatically active. Exogenous PGE2 added to isolated skeletal muscle preparations from rodents did not affect contraction, whereas it significantly fastened relaxation of a slow type muscle, such as soleus. In conclusion, COX-1 and COX-2 are expressed and enzymatically active in myocytes of skeletal muscles and hearts of rodents and humans. PGE2 appears to be the main product of COX activity in striated muscles.
KW - Cyclooxygenases
KW - Muscle
KW - Myocardium
KW - Prostaglandins
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U2 - 10.1152/japplphysiol.00288.2007
DO - 10.1152/japplphysiol.00288.2007
M3 - Article
C2 - 17673564
AN - SCOPUS:35348967814
VL - 103
SP - 1412
EP - 1418
JO - Journal of Applied Physiology
JF - Journal of Applied Physiology
SN - 8750-7587
IS - 4
ER -