title: Opiate antagonists stimulate ruminal motility of conscious goats.
abstract: The effect of opiate antagonists was determined on the extrinsic ruminal contractions of conscious goats. These contractions normally occur approximately once per minute. Naltrexone (greater than or equal to mg/kg, i.v.) and naloxone caused a significant increase in the frequency of ruminal contractions; morphine (0.8 mg/kg) depressed both frequency and amplitude. Naltrexone (12.5 micrograms/kg) prevented the response to morphine. These results suggest that an inhibitory opioid system is involved in the control of forestomach motility in goats.
mesh_terms: D000818:Animals; D005260:Female; D006041:Goats; D009020:Morphine / Q000037:antagonists & inhibitors; D009119:Muscle Contraction / Q000187:drug effects*; D009130:Muscle, Smooth / Q000187:drug effects*; D009270:Naloxone / Q000494:pharmacology; D009271:Naltrexone / Q000494:pharmacology; D009292:Narcotic Antagonists / Q000494:pharmacology*; D012417:Rumen / Q000187:drug effects
chemical_list: D009292:Narcotic Antagonists; D009270:Naloxone; D009271:Naltrexone; D009020:Morphine