title: A subclassification of multiple opiate receptors by means of selective tolerance development.
abstract: The chronic activation of opiate receptors results in the development of tolerance. On theoretical grounds, the appearance of cross-tolerance between different opioids should imply that these compounds exhibit an identical pattern on receptor activation. Tests with isolated tissue preparations, e.g. the guinea-pig ileum, made highly tolerant in vivo to the mu-agonist morphine proved that these were of almost unchanged sensitivity to different types of receptor agonists such as kappa-agonists. Thus, the ability to selectively induce tolerance on particular types of opiate receptors represents a reliable tool for the differentiation and characterization of multiple opiate receptors. Moreover, this technique facilitated the demonstration of subtypes of the already known opiate receptors.
mesh_terms: D000818:Animals; D004361:Drug Tolerance; D004558:Electric Stimulation; D006168:Guinea Pigs; D066298:In Vitro Techniques; D008297:Male; D051379:Mice; D009130:Muscle, Smooth / Q000187:drug effects; D009206:Myocardium / Q000378:metabolism; D051381:Rats; D011957:Receptors, Opioid / Q000145:classification* / Q000378:metabolism; D017473:Receptors, Opioid, kappa; D017450:Receptors, Opioid, mu; D014649:Vas Deferens / Q000187:drug effects
chemical_list: D011957:Receptors, Opioid; D017473:Receptors, Opioid, kappa; D017450:Receptors, Opioid, mu