Morphine analgesia in normal and alloxanized mice.
The analgesic response to 10 mg/kg of morphine hydrochloride, administered intraperitoneally, was examined in mice made diabetic by treatment with alloxan using the hot plate method. The hot plate base line latency of diabetic mice was significantly higher than that of normal mice. Morphine was found to possess an hyperglycaemic effect in both normal and diabetic mice. A decreased analgesic response to morphine was observed in diabetic mice. The decreased response seemed to be associated with plasma glucose levels, since multiple injections of insulin replacement abolished the decrease in morphine analgesia in diabetic mice. However, a single injection of insulin or glucose loading did not modify morphine analgesia. Naloxone was an effective antagonist of the analgesic and hyperglycaemic effects of morphine in both normal and diabetic mice, but induced a greater reduction of the plasma glucose level in diabetic than in normal mice. It is suggested that a supranormal dose of morphine may be needed in diabetics.
Department of Pharmacology, College of Pharmacy, King Saud University, Riyadh, Saudi Arabia.
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Ginawi
D000701:Analgesics, Opioid / Q000494:pharmacology*; D000818:Animals; D001786:Blood Glucose / Q000378:metabolism; D003921:Diabetes Mellitus, Experimental / Q000097:blood / Q000188:drug therapy / Q000523:psychology*; D006358:Hot Temperature; D008297:Male; D051379:Mice; D009020:Morphine / Q000494:pharmacology*; D011930:Reaction Time / Q000187:drug effects
D000701:Analgesics, Opioid; D001786:Blood Glucose; D009020:Morphine