Evidence for histamine and 5-hydroxytryptamine like effects of MK-212 on guinea pig ileum, taenia coli and rat fundus strip.
MK-212 (1 x 10(-7)M -- 1 x 10(-5)M) produced dose-dependent contractions of guinea pig ileum, taenia coil and rat fundus strip. The responses to MK-212 in all three preparations were blocked competitively by cyproheptadine (1 x 10(-8)M) a 5-HT receptor antagonist. Mepyramine (1 x 10(-8)M)-H1 receptor antagonist also inhibited competitively the responses of guinea pig ileum and taenia coli to MK-212. However, it failed to block significantly the responses of rat fundus strip to MK-212. Metiamide (1 x 10(-6)M), propranolol (1 x 10(-6)M) or atropine (1 x 10(-6)M) did not produce any significant effects on MK-212 induced contractile responses of guinea pig ileum, taenia coli and rat fundus strip. Our findings suggest that MK-212 produces both 5-HT as well as histamine like effects on the guinea-pig ileum, taenia coli and rat fundus strip.
D000818:Animals; D001285:Atropine / Q000494:pharmacology; D003533:Cyproheptadine / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D005260:Female; D005748:Gastric Fundus / Q000187:drug effects; D006168:Guinea Pigs; D006634:Histamine H1 Antagonists / Q000494:pharmacology; D006635:Histamine H2 Antagonists / Q000494:pharmacology; D007082:Ileum / Q000187:drug effects*; D066298:In Vitro Techniques; D007420:Intestine, Large / Q000187:drug effects; D008238:Lysergic Acid Diethylamide / Q000494:pharmacology; D008297:Male; D008785:Metiamide / Q000494:pharmacology; D009130:Muscle, Smooth / Q000187:drug effects*; D010879:Piperazines / Q000494:pharmacology*; D011433:Propranolol / Q000494:pharmacology; D011719:Pyrazines / Q000494:pharmacology*; D011738:Pyrilamine / Q000494:pharmacology; D051381:Rats; D011968:Receptors, Histamine / Q000187:drug effects*
D006634:Histamine H1 Antagonists; D006635:Histamine H2 Antagonists; D010879:Piperazines; D011719:Pyrazines; D011968:Receptors, Histamine; D003533:Cyproheptadine; D008785:Metiamide; C014896:6-chloro-2-(1-piperazinyl)pyrazine; D001285:Atropine; D008238:Lysergic Acid Diethylamide; D011433:Propranolol; D011738:Pyrilamine