Effect of intravenous cimetidine on mucociliary transport in anesthetized dogs.
Previous studies have shown that aerosolized histamine increases tracheal mucociliary transport velocity, whereas topically administered H1-antihistamines depress mucociliary function. Using a radiolabelled tracer method in anesthetized dogs, we determined tracheal transport velocity (TTV) before and 30 and 60 min after intravenous administration of 150 mg of cimetidine, an H2-antihistamine. In 12 experiments, 30 and 60 min after cimetidine, mean TTV increased significantly (mean changes 5.1 +/- 1.8 and 5.7 +/- 2.6 mm/min, respectively, P less than or equal to 0.05), whereas in seven control experiments in which cimetidine was not given, mean TTV did not change over 1 h (mean change 1.1 +/- 2.5 mm/min; P greater than 0.05). However, the increase in TTV after cimetidine was not significantly different from the spontaneous change in the control animals (P greater than 0.1). These results suggest that cimetidine, unlike H1-antihistamines, does not depress and may possibly improve mucociliary transport function.
D000336:Aerosols; D000771:Anesthesia, Intravenous; D000818:Animals; D002923:Cilia / Q000187:drug effects* / Q000502:physiology; D002927:Cimetidine / Q000008:administration & dosage / Q000494:pharmacology*; D003864:Depression, Chemical; D004285:Dogs; D006146:Guanidines / Q000494:pharmacology*; D006635:Histamine H2 Antagonists / Q000494:pharmacology; D007275:Injections, Intravenous; D009093:Mucus / Q000187:drug effects* / Q000502:physiology; D011970:Receptors, Histamine H2 / Q000187:drug effects; D014132:Trachea / Q000187:drug effects
D000336:Aerosols; D006146:Guanidines; D006635:Histamine H2 Antagonists; D011970:Receptors, Histamine H2; D002927:Cimetidine