Oral administration of Tyr-MIF-1 stimulates gastric emptying and gastrointestinal motility in rodents.
The effects of orally administered Tyr-MIF-1, an agonist of an endogenous antiopiate system, were examined on gastric emptying in mice and gastrointestinal myoelectric activity in rats. Tyr-MIF-1 (5 mg/kg in mice, 20 mg/kg in rats) accelerated gastric emptying of a methylcellulose test meal, increased the frequency of antral spike bursts, and disrupted intestinal migrating myoelectric complexes. These effects were reproduced by a subcutaneous administration of Tyr-MIF-1 at the same dosage. They were blocked by naloxone (1 mg/kg) but not by the kappa receptor subtype antagonist MR 2266 (1 mg/kg). The GABAA antagonist bicuculline (0.5 mg/kg), but not the GABAB antagonist 2-hydroxysaclofen (4 mg/kg), also antagonized the effects of Tyr-MIF-1. These data demonstrate that oral Tyr-MIF-1 stimulates gastric emptying and gastrointestinal motility through a systemic or central action that involves opioid and GABA systems.
Million
M
M
Department of Pharmacology, INRA, Toulouse, France.
Fioramonti
J
J
Bueno
L
L
D000279:Administration, Cutaneous; D000284:Administration, Oral; D000818:Animals; D001575:Benzomorphans / Q000494:pharmacology; D001640:Bicuculline / Q000494:pharmacology; D004435:Eating / Q000502:physiology; D004560:Electricity; D005746:Gastric Emptying / Q000187:drug effects*; D005769:Gastrointestinal Motility / Q000187:drug effects*; D009075:MSH Release-Inhibiting Hormone / Q000031:analogs & derivatives* / Q000494:pharmacology; D008297:Male; D051379:Mice; D008815:Mice, Inbred Strains; D016065:Myoelectric Complex, Migrating / Q000187:drug effects*; D009270:Naloxone / Q000494:pharmacology; D009292:Narcotic Antagonists / Q000494:pharmacology; D051381:Rats; D011919:Rats, Inbred Strains
D001575:Benzomorphans; D009292:Narcotic Antagonists; D009270:Naloxone; C027247:MR 2266; C036930:tyrosyl-prolyl-leucyl-glycinamide; D009075:MSH Release-Inhibiting Hormone; D001640:Bicuculline