Different, dose-dependent effects of verapamil inhalation on histamine-induced bronchoconstriction in anaesthetized dogs.
Different, dose-dependent effects of verapamil inhalation on histamine-induced bronchoconstriction in anaesthetized dogs are reported. Cumulative histamine dose-response curves were obtained on three groups each consisting of six dogs. These groups were: A - after atropine sulphate (1 mg/kg); B - after atropine sulphate and verapamil (approximately 0.5 mg/kg); C - after atropine sulphate and verapamil (approximately 5.0 mg/kg). Total lung resistance (R1) was measured as the indicator of bronchoconstriction. The mean maximal response of R1 in B was significant greater (p less than 0.01) than in A and C, while no significant difference was observed between A and C. A possible mechanism is postulated.
D000336:Aerosols; D000403:Airway Resistance / Q000187:drug effects; D000758:Anesthesia; D000818:Animals; D001285:Atropine / Q000494:pharmacology; D001980:Bronchi / Q000187:drug effects*; D004285:Dogs; D004305:Dose-Response Relationship, Drug; D005260:Female; D006634:Histamine H1 Antagonists; D008297:Male; D014700:Verapamil / Q000008:administration & dosage / Q000494:pharmacology*
D000336:Aerosols; D006634:Histamine H1 Antagonists; D001285:Atropine; D014700:Verapamil