title: Long-term interactions between endogenous and exogenous opiates.
abstract: The in vitro biological effect of various opiates was studied in the guinea pig ileum bioassay. Besides their direct, immediate effect, certain opiates induced sensitivity changes which persisted after their removal and the complete recovery of the preparation. These specific, asymmetrical interactions may represent long-term modulation of the opiate receptor. The in vivo pharmacological implication of opiate interaction is discussed.
mesh_terms: D000818:Animals; D004347:Drug Interactions; D004723:Endorphins / Q000494:pharmacology*; D004745:Enkephalins / Q000494:pharmacology; D006168:Guinea Pigs; D066298:In Vitro Techniques; D009020:Morphine / Q000494:pharmacology; D009119:Muscle Contraction / Q000187:drug effects; D009130:Muscle, Smooth / Q000187:drug effects; D009294:Narcotics / Q000494:pharmacology*; D013997:Time Factors
chemical_list: D004723:Endorphins; D004745:Enkephalins; D009294:Narcotics; D009020:Morphine