Opioid agonists/antagonists in morphine-tolerant squirrel monkeys
| Autor: | Mitchell J. Picker, Linda A. Dykstra, K R Powell |
|---|---|
| Rok vydání: | 1990 |
| Předmět: |
Agonist
medicine.drug_class Clinical Biochemistry (+)-Naloxone Pharmacology Toxicology Biochemistry Behavioral Neuroscience medicine Animals Saimiri Biological Psychiatry Behavior Animal Morphine Naloxone Chemistry Antagonist Stereoisomerism Drug Tolerance Analgesics Opioid Pentazocine Opioid Cyclazocine Opioid antagonist medicine.drug |
| Zdroj: | Pharmacology Biochemistry and Behavior. 36:639-644 |
| ISSN: | 0091-3057 |
| DOI: | 10.1016/0091-3057(90)90269-n |
| Popis: | The mu-opioid agonist morphine, the opioid antagonist naloxone and the isomers of the mixed action opioids, cyclazocine, n-allylnormetazocine, and pentazocine were examined in squirrel monkeys responding under a fixed-ratio 30 schedule of food presentation. Dose-effect curves for all drugs were obtained prior to, during, and following a chronic regimen in which monkeys received 6 mg/kg/day of morphine. When compared to the dose-effect curves obtained prior to the chronic regimen, the morphine dose-effect curve obtained during the chronic regimen was shifted to the right 0.5–1.0 log unit, whereas the naloxone dose-effect curve shifted over 3 log units to the left. No changes were observed between the prechronic and chronic dose-effect curves for (+)-cyclazocine, (+)-n-allylnormetazocine, and (+)- or (−)-pentazocine. The (−) isomers of n-allylnormetazocine and cyclazocine shifted 0.6–1.7 log units to the left. These results suggest that the (−) isomers of cyclazocine and n-allylnormetazocine have mu antagonist properties which are revealed during chronic morphine administration. |
| Databáze: | OpenAIRE |
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