Evidence of hyperglycemic hyperalgesia by quinpirole.
Male albino rats were tested for antinociception following injections (IP) with saline, quinpirole (Quin) (1 mg/kg), morphine sulfate (M.S.) (5 mg/kg), or both Quin and M.S. (1 mg/kg and 5 mg/kg, respectively). Quin reduced and M.S. increased tail-flick latency as compared to controls. Tail-flick latencies of the animals injected with both drugs were significantly reduced as compared M.S. alone. Quin increased blood glucose levels by 96 percent, as compared to saline controls. In competitive binding studies Quin displaced 3H-DAGO (IC50 = 29.8 microM). CD-1 mice demonstrated a naloxone-reversible analgesia following ICV Quin (100 micrograms). These data are consistent with the hypothesis that the hyperglycemic effects of Quin attenuate M.S. analgesia while the antinociceptive effects of Quin may be mediated through opioid receptors.
Division of Pharmacology and Toxicology, School of Pharmacy, Northeast Louisiana University, Monroe 71270.
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D000818:Animals; D001786:Blood Glucose / Q000378:metabolism; D001923:Brain Chemistry / Q000187:drug effects; D015259:Dopamine Agents / Q000633:toxicity*; D004305:Dose-Response Relationship, Drug; D004873:Ergolines / Q000008:administration & dosage / Q000633:toxicity*; D006943:Hyperglycemia / Q000139:chemically induced* / Q000503:physiopathology; D007276:Injections, Intraventricular; D008297:Male; D009020:Morphine / Q000494:pharmacology; D010146:Pain / Q000139:chemically induced* / Q000503:physiopathology; D019257:Quinpirole; D051381:Rats; D011919:Rats, Inbred Strains; D011957:Receptors, Opioid / Q000187:drug effects; D017450:Receptors, Opioid, mu; D012684:Sensory Thresholds / Q000187:drug effects
D001786:Blood Glucose; D015259:Dopamine Agents; D004873:Ergolines; D011957:Receptors, Opioid; D017450:Receptors, Opioid, mu; D019257:Quinpirole; D009020:Morphine