[Effect of calmidazolium (R 24571) on the electrical and contractile properties of smooth muscle cells in the guinea pig ureter].
Calmidazolium in macromolecular concentrations inhibited the electric and contractile activity of smooth muscle cells (SMC). The concentrations causing a 50% inhibition of oscillations on the action potential (AP) plate were equal to 1 X 10(-6) microM, AP amplitude was 3 X 10(-6) microM and contraction amplitude was 1 X 10(-6) microM. Calcium ionophore A 23187/8 X 10(-7) microM, added to the normal Krebs solution, decreased rapid AP components amplitude and increased the contraction power of the isolated SMC strip by 62 +/- 9%. A 23187, though to a lesser extent, increased smooth muscle contractions during the action of calmidazolium. With combined use of A 23187 and calmidazolium, rapid AP components were depressed to a greater extent than each of them taken separately. The data obtained point to the presence of calmodulin or similar protein in SMC of the calcium channels.
D000200:Action Potentials / Q000187:drug effects; D000818:Animals; D000001:Calcimycin / Q000494:pharmacology; D002147:Calmodulin / Q000037:antagonists & inhibitors*; D003864:Depression, Chemical; D004305:Dose-Response Relationship, Drug; D004347:Drug Interactions; D006168:Guinea Pigs; D007093:Imidazoles / Q000494:pharmacology*; D066298:In Vitro Techniques; D008564:Membrane Potentials / Q000187:drug effects; D009119:Muscle Contraction / Q000187:drug effects*; D009130:Muscle, Smooth / Q000187:drug effects* / Q000502:physiology
D002147:Calmodulin; D007093:Imidazoles; D000001:Calcimycin; C031938:calmidazolium
Vliianie kal'midozoliuma (R 24571) na élektricheskie i sokratitel'nye svoĭstva gladkomyshechnykh kletok mochetochnika morskoĭ svinki.