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: Subsensitivity to the cough-depressant effects of opioid and nonopioid antitussives in morphine-dependent rats: relationship to central serotonin function.
    Author: Kamei J, Mori T, Ogawa M, Kasuya Y.
    Journal: Pharmacol Biochem Behav; 1989 Nov; 34(3):595-8. PubMed ID: 2637700.
    Abstract:
    The present study was designed to determine whether morphine-dependent rats have a decreased sensitivity to the cough-depressant effects of both opioid and nonopioid antitussives. Morphine dependence was induced by treatment with morphine-admixed food (0.5 mg/g of food) for 7 days. The cough reflex was induced by application of electrical stimulation to the tracheal mucosa by the puncture electrode-induced cough method. The cough-depressant effect was evaluated as the antitussive ED50 calculated by the method of Litchfield and Wilcoxon. The effects of both opioid (morphine and dihydrocodeine) and nonopioid (dextromethorphan and noscapine) antitussive drugs were diminished in morphine-dependent rats. The values of ED50 of these antitussive drugs in morphine-dependent rats were about 3-fold higher than those in control rats. A significantly lower number of serotonin receptors was found in the brainstem of morphine-dependent rats (Bmax: 2.88 +/- 0.32 pmoles/mg protein) than in controls (Bmax: 4.93 +/- 0.50 pmoles/mg protein). It is possible that the decreased sensitivity to both opioid and nonopioid antitussive drugs, in terms of the depression of the cough reflex, in morphine-dependent rats may be due to changes in the number of serotonin receptors.
    [Abstract] [Full Text] [Related] [New Search]