Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0278080 (physical dependence)
 1,658 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Female Sprague-Dawley rats were prepared with chronic cortical and temporalis muscle electrodes and i.v. cannulas. They were administered i.v. injections of morphine to produce tolerance and physical dependence, then trained to lever press for i.v. self-injections of morphine (10 mg/kg) to maintain dependence. They were subsequently withdrawn for two weeks, implanted subcutaneously with one or two pellets of naloxone base, 100 mg each, or placebo pellets, returned to the experimental cages and allowed to relapse to self-administration of either saline or morphine. Rats with placebo pellets relapsed to morphine self-administration and reestablished the dependence state. However, rats implanted with naloxone and then permitted to self-administer morphine extinguished their lever pressing ("drug-seeking behavior"). Similar results were obtained with rats implanted with placebo pellets and self-administering saline. The self-injections of morphine by rats implanted with placebo pellets severely suppressed REM sleep and altered its normal distribution. Rats implanted with naloxone pellets and that subsequently extinguished their lever pressing, however, did not exhibit a change in REM sleep distributions. Similarly, self-injections of isotonic saline did not exert an effect on REM sleep distributions. These findings suggest that a correlation between REM sleep distributions, drug-seeking behavior, and morphine-naloxone interaction prevailed.
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PMID:REM sleep distributions in post-addict rats relapsing to morphine self-administration: effects of naloxone subcutaneous pellets. 16 24

Rats maintained dependence by the self-administration of LAAM or morphine. Following the substitution of saline for LAAM, REM sleep was not disrupted, and the frequency of lever pressing for saline self-injections peaked at about 24 hr. In contrast, following the substitution of saline for morphine, REM sleep was suppressed for 24 hr while the frequency of lever pressing for saline self-injections peaked within 8 hr. When abstinence was induced by hourly iv naloxone injections, REM sleep occurrences were suppressed to a similar degree and for similar durations during naloxone-induced abstinence from both morphine and LAAM. These results suggest that the level of physical dependence maintained during self-administration of LAAM and morphine was similar. The relatively mild abstinence syndrome that was seen during saline substitution in LAAM-dependent rats was most likely related to the long plasma half-lives of the pharmacologically active N-demethylated metabolites of LAAM.
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PMID:Spontaneous vs. naloxone-induced abstinence in dependent rats self-administering L-alpha-acetylmethadol (LAAM) or morphine. 22 73

The purpose of the study was to define possible self-administration of nalbuphine, butorphanol and pentazocine by morphine post-addict rats. Rats were prepared with permanent EEG and EMG electrodes and indwelling IV cannulae, made tolerant to and physically dependent on morphine, then trained to lever press for morphine IV self-injections on a fixed ratio (FR) 20 schedule of reinforcement. Rats were then spontaneously withdrawn from morphine. When these morphine post-addict rats were returned to the experimental cages three to four weeks later, they were found to reestablish self-administration of morphine as well as to establish self-administration of nalbuphine, butorphanol and pentazocine. Suppression of REM sleep for at least 30 min was apparent following self-injections of these agents. After the stabilization of self-injection patterns, withdrawal from nalbuphine and pentazocine was found to be associated with intense abstinence symptoms. However, withdrawal from morphine and butorphanol was not. It can be concluded that while drug-seeking behavior for the above narcotics in morphine post-addict rats was analogous as measured by self-administration, nalbuphine and butorphanol appeared to produce lower levels of physical dependence.
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PMID:Self-administration of nalbuphine, butorphanol and pentazocine by morphine post-addict rats. 719 84