Attenuation of morphine tolerance and dependence in scopolamine-treated rats.
Morphine tolerance and dependence were investigated in scopolamine-treated rats. The results showed that scopolamine treatment (up to 2 mg/kg) did not affect basal line or morphine-induced latency in the tail-flick test but significantly increased the escape latency in the Morris water-maze task. Co-administration of scopolamine could considerably attenuate development of morphine tolerance and naloxone-precipitated withdrawal syndrome. Pretreatment of scopolamine for 7 days prior to morphine administration also significantly reduced the tolerance and withdrawal symptoms. Scopolamine treatment was further shown to attenuate morphine-induced conditioned place preference, an indicator of morphine psychological dependence. The present study demonstrated the attenuation of morphine tolerance and dependence in scopolamine-treated animals, probably related to scopolamine-produced learning and memory impairment.
Zhou
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H
Shanghai Institute of Cell Biology, Chinese Academy of Sciences, People's Republic of China.
Ge
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X
Wang
L Z
LZ
Ma
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L
Pei
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G
D000701:Analgesics, Opioid / Q000494:pharmacology*; D000704:Analysis of Variance; D000818:Animals; D004347:Drug Interactions; D004361:Drug Tolerance; D008297:Male; D018782:Maze Learning / Q000187:drug effects; D009020:Morphine / Q000009:adverse effects / Q000494:pharmacology*; D009021:Morphine Dependence; D009270:Naloxone / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley; D011930:Reaction Time / Q000187:drug effects; D012601:Scopolamine / Q000494:pharmacology*; D013375:Substance Withdrawal Syndrome
D000701:Analgesics, Opioid; D009270:Naloxone; D009020:Morphine; D012601:Scopolamine