Some properties of calcium-induced contraction in the isolated human and guinea-pig tracheal smooth muscle.
We studied the effects of the cyclooxygenase inhibitors, indomethacin and aspirin, the leukotriene antagonist, FPL 55712 and the Ca antagonist, verapamil on basal tone and Ca-induced contractions in the human and guinea-pig tracheal muscle. Indomethacin and aspirin usually increased spontaneous tone or Ca-induced contractions in human strips, while consistently decreased tension development in the guinea-pig muscle. FPL 55712 strongly reduced contractions in the human, whereas it had a very weak effect on the guinea-pig muscle. Verapamil had a small inhibitory effect in the human trachea, either at 5.9 or 40 mM K, but markedly suppressed Ca-induced contractions of guinea-pig trachea in 40 mM K and had little effect on contractions in 5.9 mM K in this tissue. It is concluded that active tone in the two different tracheal muscles were controlled by different processes; that different arachidonate by-products may exert an effect on basal tone in the two different muscles; and that different plasma membrane Ca channels may be operative under basal conditions in the different muscles.
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D000368:Aged; D000818:Animals; D001241:Aspirin / Q000494:pharmacology; D002118:Calcium / Q000494:pharmacology*; D002867:Chromones / Q000494:pharmacology; D005260:Female; D006168:Guinea Pigs; D006801:Humans; D007213:Indomethacin / Q000494:pharmacology; D007473:Ion Channels / Q000187:drug effects; D008297:Male; D008875:Middle Aged; D009119:Muscle Contraction / Q000187:drug effects*; D009129:Muscle Tonus / Q000187:drug effects; D009130:Muscle, Smooth / Q000187:drug effects / Q000502:physiology*; D013189:SRS-A / Q000037:antagonists & inhibitors; D014132:Trachea / Q000187:drug effects / Q000502:physiology; D014700:Verapamil / Q000494:pharmacology
D002867:Chromones; D007473:Ion Channels; D013189:SRS-A; C006312:FPL 55712; D014700:Verapamil; D001241:Aspirin; D002118:Calcium; D007213:Indomethacin