title: Regional distribution of an opioid mechanism in the guinea-pig isolated intestine.
abstract: Opioid receptor blockade by naloxone enhanced peristalsis in isolated segments from the guinea-pig duodenum, jejunum and ileum, increasingly aborally. Thus, an increase in the influence of an intrinsic opioid mechanism may be responsible for decrease in the level of peristaltic activity, observed aborally. However, the peristalsis of ileal segments which worked against their closed distal end was enhanced by naloxone to a similar degree as normal peristalsis.
mesh_terms: D000818:Animals; D004723:Endorphins / Q000502:physiology*; D005260:Female; D006168:Guinea Pigs; D066298:In Vitro Techniques; D007413:Intestinal Mucosa / Q000187:drug effects; D007421:Intestine, Small / Q000187:drug effects / Q000502:physiology*; D008297:Male; D009270:Naloxone / Q000494:pharmacology; D010528:Peristalsis / Q000187:drug effects; D013997:Time Factors
chemical_list: D004723:Endorphins; D009270:Naloxone