title: Effects of Allyl Isothiocyanate, Acetaminophen, and Dipyrone in the Guinea-Pig Ileum.
abstract: Allyl isothiocyanate (AITC, mustard oil, 50-200 µmol/l), depending on specific dosages, inhibited the cholinergic twitch response in the longitudinal muscle-myenteric plexus (LMMP) strip of the guinea-pig ileum. AITC also induced short-lasting contractile responses, and decreases of the basal tone of the LMMP strip at low concentrations and increases at high concentrations. Hexamethonium, a blocker of nicotinic ganglionic transmission, was able to prevent the AITC-evoked inhibitory effect, an effect that was also observed with the opioid antagonist naloxone. The P2 purinoceptor antagonist pyridoxalphosphate-6-azophenyl-2'-4'-disulphonic acid and guanethidine had no significant influence on the inhibitory effect of AITC. Since AITC also reduced the electrical stimulation-induced myogenic smooth muscle contractions in the LMMP preparation, its contractile and relaxant actions can be regarded as neurogenic and myogenic in nature. The analgesics, acetaminophen (paracetamol, 100-500 µmol/l) and dipyrone (metamizole, 100-500 µmol/l), reduced both the cholinergic twitch and the myogenic contractions in the LMMP strip to the same extent; therefore, their action in the intestinal smooth muscle can be regarded as myogenic spasmolytic in nature.
authors.affiliation: Institute of Experimental and Clinical Pharmacology, Medical University Graz, Graz, Austria.
authors.forename: Josef
authors.initials: J
authors.lastname: Donnerer
authors.forename: Ingrid
authors.initials: I
authors.lastname: Liebmann
mesh_terms: D000082:Acetaminophen / Q000494:pharmacology*; D000700:Analgesics / Q000494:pharmacology; D000818:Animals; D004177:Dipyrone / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D006168:Guinea Pigs; D007082:Ileum / Q000187:drug effects* / Q000502:physiology; D017879:Isothiocyanates / Q000494:pharmacology*; D008297:Male; D009119:Muscle Contraction / Q000187:drug effects* / Q000502:physiology; D009292:Narcotic Antagonists / Q000494:pharmacology; D009924:Organ Culture Techniques
chemical_list: D000700:Analgesics; D017879:Isothiocyanates; D009292:Narcotic Antagonists; D000082:Acetaminophen; D004177:Dipyrone; C004471:allyl isothiocyanate