Cimetidine does not impair pulmonary clearance of Pseudomonas aeruginosa in normal rats.
Histamine (H2)-receptor blockers are commonly used in critically ill patients to prevent gastric bleeding and have been implicated in the pathogenesis of gram-negative bacterial (GNB) nosocomial pneumonia. These experiments were undertaken to determine if cimetidine affects pulmonary GNB clearance. Groups of normal Sprague-Dawley rats were given cimetidine (75 mg/kg) or an equal volume of sterile buffer intraperitoneally every 6 hr for 24 hr prior to intratracheal challenge with 1.0 x 10(8) Pseudomonas aeruginosa. At 6 and 24 hr after challenge, animals were sacrificed and gastric pH, quantitative lung cultures, and total and differential [alveolar macrophages (AM) and polymorphonuclear leukocytes (PMN)] cell counts in bronchoalveolar lavage fluid were performed. Results showed that cimetidine therapy resulting in gastric pH greater than 4.0 has no effect on the pulmonary clearance of P. aeruginosa.
Daon
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E
Pulmonary/Critical Care Medicine, LSUMC, New Orleans 70112.
Summer
W
W
Nelson
S
S
Mason
C
C
D000818:Animals; D001992:Bronchoalveolar Lavage Fluid / Q000166:cytology; D002452:Cell Count; D002927:Cimetidine / Q000494:pharmacology*; D005745:Gastric Acidity Determination; D008168:Lung / Q000382:microbiology*; D016676:Macrophages, Alveolar / Q000166:cytology; D009504:Neutrophils / Q000166:cytology; D011550:Pseudomonas aeruginosa / Q000502:physiology*; D051381:Rats; D017207:Rats, Sprague-Dawley
D002927:Cimetidine