Studies investigating the possible involvement of adenosine in the antisecretory action of morphine.
1. Fluid secretion was induced in the jejunum of anesthetised rats using vasoactive intestinal peptide. 2. The adenosine antagonist, DPCPX (0.1 mg/kg), suppressed the antisecretory action of morphine (10 mg/kg), but naloxone (80 micrograms/kg) did not inhibit the antisecretory response of the adenosine agonist, NECA (40 micrograms/kg), at a dose previously shown to antagonize the antisecretory response of morphine. 3. NECA (40 (micrograms/kg) reversed secretion in pithed and reserpine-pretreated (5 mg/kg subcutaneously) rats. 4. It is proposed that adenosine acts as a mediator of the morphine antisecretory effect at a site distal to the noradrenergic neurons involved in the action of morphine.
Hancock
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Victorian College of Pharmacy, Monash University, Department of Pharmaceutical Biology and Pharmacology, Parkville Victoria, Australia.
Coupar
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D000241:Adenosine / Q000031:analogs & derivatives / Q000037:antagonists & inhibitors / Q000378:metabolism* / Q000494:pharmacology; D019830:Adenosine-5'-(N-ethylcarboxamide); D000818:Animals; D003655:Decerebrate State; D005260:Female; D007413:Intestinal Mucosa / Q000187:drug effects* / Q000378:metabolism; D007583:Jejunum / Q000187:drug effects* / Q000378:metabolism; D008297:Male; D009020:Morphine / Q000494:pharmacology*; D009270:Naloxone / Q000494:pharmacology; D009292:Narcotic Antagonists / Q000494:pharmacology; D009638:Norepinephrine / Q000378:metabolism; D058906:Purinergic P1 Receptor Agonists; D051381:Rats; D017208:Rats, Wistar; D012110:Reserpine / Q000494:pharmacology; D013565:Sympatholytics / Q000494:pharmacology; D014660:Vasoactive Intestinal Peptide / Q000494:pharmacology; D014970:Xanthines / Q000494:pharmacology
D009292:Narcotic Antagonists; D058906:Purinergic P1 Receptor Agonists; D013565:Sympatholytics; D014970:Xanthines; D019830:Adenosine-5'-(N-ethylcarboxamide); D009270:Naloxone; D014660:Vasoactive Intestinal Peptide; D009020:Morphine; D012110:Reserpine; C051360:1,3-dipropyl-8-cyclopentylxanthine; D000241:Adenosine; D009638:Norepinephrine