Antispasmogenic and spasmolytic effects of verapamil and salbutamol, alone and in combination, on histamine-induced guinea pig tracheal contraction in vitro.
The antispasmogenic and spasmolytic effects of the calcium entry blocker verapamil were examined on histamine-induced guinea pig tracheal contraction in vitro in comparison with the beta 2-adrenergic agonist salbutamol. The effects of verapamil were found to be about 1000 times weaker than those of salbutamol. The antispasmogenic IC50 for verapamil was 1.99 x 10(-4) M compared to 7.94 x 10(-8) M for salbutamol. The spasmolytic EC50 for verapamil was 3.37 x 10(-5) M and for salbutamol was 1.95 x 10(-8) M. The combined application of verapamil and salbutamol resulted in additive antispasmogenic and spasmolytic effects.
Department of Pharmacology, Medical University of Varna, Bulgaria.
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Valcheva
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Belcheva
D000420:Albuterol / Q000494:pharmacology*; D000818:Animals; D006168:Guinea Pigs; D006632:Histamine / Q000494:pharmacology*; D066298:In Vitro Techniques; D008297:Male; D009130:Muscle, Smooth / Q000187:drug effects*; D010276:Parasympatholytics / Q000494:pharmacology*; D013035:Spasm / Q000139:chemically induced* / Q000503:physiopathology; D014132:Trachea / Q000187:drug effects; D014700:Verapamil / Q000494:pharmacology*
D010276:Parasympatholytics; D006632:Histamine; D014700:Verapamil; D000420:Albuterol