Biomaterial Database

Properties of a selective kappa agonist, U-50,488H. 1982

R A Lahti, and P F VonVoigtlander, and C Barsuhn

U-50,488H has been shown to be a naloxone antagonizable analgesic in rodents. However, the dose of naloxone needed for antagonism is higher than it is for morphine. U-50,488H does not produce physical dependence; however it does produce tolerance upon chronic administration. U-50,488H is cross tolerant with bremazocine but not with morphine. Monkeys trained to discriminate ethylketocyclazocine (EKC) from saline show a complete generalization to U-50,488H but not to morphine. The evaluation of U-50,488H in 3H-EKC site-selective binding indicated that U-50,488H has a high affinity for the kappa receptor (Ki = 114 nM) and a low affinity for the mu receptor (Ki = 6100 nM). The ratio of Ku/Kk was 0.08 for morphine, 0.4 for dynorphin, and 53.5 for U-50,488H. The data suggest that U-50,488H is a selective agonist at the opioid kappa receptor.

UI	MeSH Term	Description	Entries
D007082	Ileum	The distal and narrowest portion of the SMALL INTESTINE, between the JEJUNUM and the ILEOCECAL VALVE of the LARGE INTESTINE.
D007202	Indicators and Reagents	Substances used for the detection, identification, analysis, etc. of chemical, biological, or pathologic processes or conditions. Indicators are substances that change in physical appearance, e.g., color, at or approaching the endpoint of a chemical titration, e.g., on the passage between acidity and alkalinity. Reagents are substances used for the detection or determination of another substance by chemical or microscopical means, especially analysis. Types of reagents are precipitants, solvents, oxidizers, reducers, fluxes, and colorimetric reagents. (From Grant & Hackh's Chemical Dictionary, 5th ed, p301, p499)	Indicator,Reagent,Reagents,Indicators,Reagents and Indicators
D007700	Kinetics	The rate dynamics in chemical or physical systems.
D008297	Male		Males
D009119	Muscle Contraction	A process leading to shortening and/or development of tension in muscle tissue. Muscle contraction occurs by a sliding filament mechanism whereby actin filaments slide inward among the myosin filaments.	Inotropism,Muscular Contraction,Contraction, Muscle,Contraction, Muscular,Contractions, Muscle,Contractions, Muscular,Inotropisms,Muscle Contractions,Muscular Contractions
D011957	Receptors, Opioid	Cell membrane proteins that bind opioids and trigger intracellular changes which influence the behavior of cells. The endogenous ligands for opioid receptors in mammals include three families of peptides, the enkephalins, endorphins, and dynorphins. The receptor classes include mu, delta, and kappa receptors. Sigma receptors bind several psychoactive substances, including certain opioids, but their endogenous ligands are not known.	Endorphin Receptors,Enkephalin Receptors,Narcotic Receptors,Opioid Receptors,Receptors, Endorphin,Receptors, Enkephalin,Receptors, Narcotic,Receptors, Opiate,Endorphin Receptor,Enkephalin Receptor,Normorphine Receptors,Opiate Receptor,Opiate Receptors,Opioid Receptor,Receptors, Normorphine,Receptors, beta-Endorphin,beta-Endorphin Receptor,Receptor, Endorphin,Receptor, Enkephalin,Receptor, Opiate,Receptor, Opioid,Receptor, beta-Endorphin,Receptors, beta Endorphin,beta Endorphin Receptor,beta-Endorphin Receptors
D003496	Cyclazocine	An analgesic with mixed narcotic agonist-antagonist properties.
D004745	Enkephalins	One of the three major families of endogenous opioid peptides. The enkephalins are pentapeptides that are widespread in the central and peripheral nervous systems and in the adrenal medulla.	Enkephalin
D006168	Guinea Pigs	A common name used for the genus Cavia. The most common species is Cavia porcellus which is the domesticated guinea pig used for pets and biomedical research.	Cavia,Cavia porcellus,Guinea Pig,Pig, Guinea,Pigs, Guinea
D000701	Analgesics, Opioid	Compounds with activity like OPIATE ALKALOIDS, acting at OPIOID RECEPTORS. Properties include induction of ANALGESIA or NARCOSIS.	Opioid,Opioid Analgesic,Opioid Analgesics,Opioids,Full Opioid Agonists,Opioid Full Agonists,Opioid Mixed Agonist-Antagonists,Opioid Partial Agonists,Partial Opioid Agonists,Agonist-Antagonists, Opioid Mixed,Agonists, Full Opioid,Agonists, Opioid Full,Agonists, Opioid Partial,Agonists, Partial Opioid,Analgesic, Opioid,Full Agonists, Opioid,Mixed Agonist-Antagonists, Opioid,Opioid Agonists, Full,Opioid Agonists, Partial,Opioid Mixed Agonist Antagonists,Partial Agonists, Opioid