Effects of morphine, nalorphine and morphine withdrawal on lethal toxicity of intracerebroventricular kainic acid in mice.
The effects of morphine, nalorphine and morphine withdrawal on intracerebroventricular kainic acid (0.1 and 0.2 micrometers) lethal toxicity were examined. Morphine (40 mg/kg) potentiated the lethal effect of a low (0.1 micrometer) but not that of a higher dose (0.2 micrometer) of kainic acid. Nalorphine (20 mg/kg) did not affect the toxic action of kainic acid. The mice during morphine withdrawal were very sensitive to the lethal effects of both doses of the amino acid. Kainic acid toxicity seems to be closely related to the functional state of the opiate system. Moreover, it seems that in tolerant animals a supersensitivity of glutamatergic receptors is likely to occur.
D000818:Animals; D004357:Drug Synergism; D006801:Humans; D007608:Kainic Acid / Q000633:toxicity*; D008297:Male; D051379:Mice; D009020:Morphine / Q000494:pharmacology*; D009269:Nalorphine / Q000494:pharmacology*; D011759:Pyrrolidines / Q000633:toxicity*; D013375:Substance Withdrawal Syndrome
D011759:Pyrrolidines; D009020:Morphine; D007608:Kainic Acid; D009269:Nalorphine