These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.
Pubmed for Handhelds
PUBMED FOR HANDHELDS
Search MEDLINE/PubMed
Title: Modification of airway histamine-receptor function with methylprednisolone succinate. Author: Ahmed T, King MM, Krainson JP. Journal: J Allergy Clin Immunol; 1983 Feb; 71(2):224-9. PubMed ID: 6337199. Abstract: The purpose of the present study was to investigate whether glucocorticosteroids alter airway histamine-receptor function. We measured pulmonary resistance in six conscious sheep before and after inhalation challenge with 100 breaths of 5% histamine solution, without and with intravenous pretreatment with the specific H1- and H2-receptor antagonists. Inhalation of histamine (combined H1 and H2 stimulation) increased mean pulmonary resistance (RL) to 290% of baseline (p less than 0.05). Pretreatment with the H2 antagonist, metiamide (selective H1 stimulation), enhanced the effect of histamine, with a mean RL increase to 760% of baseline (p less than 0.05). Histamine challenge after pretreatment with the H1 antagonist, chlorpheniramine (selective H2 stimulation), decreased RL to 40% of chlorpheniramine value (p less than 0.05). A single intravenous bolus injection of methylprednisolone succinate (30 mg/kg) 30 min before histamine challenge suppressed the airway responsiveness to histamine, with a mean RL increase to only 186% of baseline. After methylprednisolone, selective H1-receptor stimulation with histamine elicited a blunted H1-receptor response; mean RL increased to only 248% of baseline. Both changes were significantly lower than that with histamine alone (p less than 0.05). Methylprednisolone per se blunted the chlorpheniramine-induced increase in RL which made it difficult to evaluate H2-receptor function (RL decreased to 67% of postchlorpheniramine value). However, in the presence of increased airway tone with carbachol, selective H2 stimulation with histamine decreased RL to 26% of postcarbachol value (p less than 0.05), thus excluding suppression of H2 receptors. Methylprednisolone had no effect on carbachol-induced increase in RL. In conscious sheep, methylprednisolone blunts airway responsiveness to histamine by suppressing H1 receptors without significantly altering H2 receptors or cholinergic-receptor function.[Abstract] [Full Text] [Related] [New Search]