Single dose tolerance and cross tolerance studies with the endorphins in isolated guinea pig ileum.
D000818:Animals; D004361:Drug Tolerance; D004723:Endorphins / Q000494:pharmacology*; D006168:Guinea Pigs; D007082:Ileum / Q000187:drug effects; D066298:In Vitro Techniques; D009119:Muscle Contraction / Q000187:drug effects*; D009130:Muscle, Smooth / Q000187:drug effects*; D009294:Narcotics / Q000494:pharmacology
D004723:Endorphins; D009294:Narcotics