Endothelin-1 and carbachol: differences in contractile effects and myosin phosphorylation in lamb tracheal smooth muscle.
Endothelin-1 is a new potent vasoconstrictor peptide produced by the endothelial cells. The contractile effects of endothelin-1 (ET-1) were compared with those of cabachol in lamb tracheal smooth muscle. Equimolar concentrations (10(-6)M) of endothelin 1 and carbachol elicit rapidly rising isometric tension which is maintained indefinitely in a steady state when fibres are stimulated with carbachol. Fibre strips exposed to ET-1 cannot maintain peak isometric force beyond 15-20 min and instead these exhibit a decline in tension towards near relaxed state. In addition to an early transient relaxation, ET-1 stimulation results in a 20,000 Da myosin light chain phosphorylation pattern different from that of carbachol stimulation.
Katoch
S S
SS
Department of Biosciences, Himachal Pradesh University, Summer Hill, Simla.
D000818:Animals; D002217:Carbachol / Q000494:pharmacology*; D016232:Endothelins / Q000494:pharmacology*; D066298:In Vitro Techniques; D007537:Isometric Contraction / Q000187:drug effects; D009119:Muscle Contraction / Q000187:drug effects; D009130:Muscle, Smooth / Q000187:drug effects* / Q000378:metabolism; D009218:Myosins / Q000378:metabolism*; D010766:Phosphorylation; D012756:Sheep; D014132:Trachea / Q000187:drug effects / Q000378:metabolism
D016232:Endothelins; D002217:Carbachol; D009218:Myosins