The dependence of airway smooth muscle on extracellular Ca2+ for contraction is influenced by the presence of cartilage.
Isolated guinea-pig and rabbit airway smooth muscle preparations lacking cartilage are less able to contract, in response to methacholine, histamine and K+, in the absence of extracellular Ca2+ than cartilage-containing preparations removed from the same animal. Cartilage apparently provides utilizable Ca2+ for contraction of airway smooth muscle. The presence of cartilage, therefore, affects the apparent dependence of the isolated smooth muscle on extracellular Ca2+ for contraction.
D000818:Animals; D002118:Calcium / Q000494:pharmacology*; D002356:Cartilage / Q000502:physiology*; D006168:Guinea Pigs; D006632:Histamine / Q000494:pharmacology; D066298:In Vitro Techniques; D007700:Kinetics; D016210:Methacholine Chloride; D008688:Methacholine Compounds / Q000494:pharmacology; D009119:Muscle Contraction / Q000187:drug effects*; D009130:Muscle, Smooth / Q000187:drug effects / Q000502:physiology*; D011188:Potassium / Q000494:pharmacology; D011817:Rabbits; D014132:Trachea / Q000187:drug effects / Q000502:physiology
D008688:Methacholine Compounds; D016210:Methacholine Chloride; D006632:Histamine; D011188:Potassium; D002118:Calcium