The endothelin receptor profile in L6 myotubes.
In this study we characterized the endothelin (ET) receptors of cultured L6 myotubes in order to gain a further insight into the mechanism of the ET effect on skeletal muscle cells. Displacements of 125I-ET-1 by unlabeled ET-1, ET-2 and ET-3 revealed receptors with a high affinity (Kd < 1 nmol/l) to ET-1 and ET-2 and a low affinity (Kd > 100 nmol/l) to ET-3, which suggested the presence of primarily ETA receptors on L6 myotubes. These findings were complemented by displacement binding kinetics, in which the ETA receptor antagonist JKC-301 was used. More-over, the ET-1-evoked increase in the cytosolic free Ca was blocked by JKC-301 but not by the ETB receptor antagonist IRL-1038. Collectively, these findings indicate that the ET-mediated response in cultured skeletal muscle cells is through the ETA receptor.
Fekete
Z
Z
Hypertension Research Center, University of Medicine and Dentistry of New Jersey, New Jersey Medical School, Newark, USA.
Yang
X Y
XY
Kimura
M
M
Aviv
A
A
D002118:Calcium / Q000378:metabolism; D002478:Cells, Cultured; D065128:Endothelin Receptor Antagonists; D016232:Endothelins / Q000378:metabolism; D006801:Humans; D007457:Iodine Radioisotopes; D007700:Kinetics; D018485:Muscle Fibers, Skeletal / Q000166:cytology / Q000648:ultrastructure*; D009842:Oligopeptides; D017466:Receptors, Endothelin / Q000378:metabolism / Q000502:physiology*
D065128:Endothelin Receptor Antagonists; D016232:Endothelins; D007457:Iodine Radioisotopes; C096173:JKC 301; D009842:Oligopeptides; D017466:Receptors, Endothelin; D002118:Calcium