Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0596240 (cancer pain)
 3,066 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Cannabinoid agonists have shown some promise clinically as analgesics, in particular for cancer pain, in which they have the additional benefit of decreasing nausea. However, as for most other drugs, the long-term use of cannabinoids is limited by the development of tolerance. Several molecular mechanisms have been proposed to explain drug tolerance, including receptor downregulation. The cannabinoid 1 (CB1) receptors can be downregulated in vitro through an interaction with the G-protein-coupled receptor-associated sorting protein1, GASP1, that targets CB1 receptors for degradation after their agonist-mediated endocytosis. To investigate whether GASP1-mediated postendocytic sorting of the CB1 receptor contributes to tolerance to cannabinoid drugs in vivo, we generated a mouse with a disruption of GASP1. In wild-type mice, repeated administration of the cannabinoid agonist WIN55,212-2 promoted downregulation of CB1 receptor levels and concomitant tolerance to the effects of drug on antinociception, motor incoordination, and locomotor hypoactivity. In contrast, GASP1 knockout mice did not develop tolerance to any of these effects and showed no significant receptor downregulation. Taken together, this study provides evidence that GASP1 regulates CB1 receptor downregulation in vivo, and that postendocytic receptor trafficking has a key role in the development of tolerance to WIN55,212-2.
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PMID:Differential regulation of behavioral tolerance to WIN55,212-2 by GASP1. 2016 30

Mu-opioids (i.e. morphine, oxycodone, hydrocodone) are considered to be the primary drugs for treatment of moderate to severe acute, chronic and cancer pain. Despite their analgesic effectiveness they have several clinically significant side-effects (cognitive, motor, respiratory, cardiovascular, gastrointestinal). They also have a limited spectrum of action, being more effective for nociceptive than neuropathic pain. In an effort to identify other opioid analgesics with greater effectiveness in mixed pain states and with a better side-effect profile compared to the classical mu-opioid agonist, morphine, a relatively little-known morphine derivative, morphine-6-O-sulfate, was characterized using a range of well-established rodent pain models. The present data demonstrated that morphine-6-O-sulfate was efficacious after several routes of administration, including neuroaxial (intrathecal), parenteral (intraperitoneal) and oral in the rat. It showed potent, dose-related, analgesic activities against acute nociceptive pain (the tail flick test), neuropathic pain (chronic constriction nerve injury hyperalgesia and allodynia) and inflammatory pain (formalin test). It had a good separation based on dose (at least 10-fold) between side-effects (incoordination, hypolocomotion, inhibition of gastrointestinal motility) and analgesia in all models of pain tested. In addition, morphine-6-O-sulfate had a more favorable potency ratio for delay of gastrointestinal transit and analgesia when compared to morphine. These preclinical findings suggest that morphine-6-O-sulfate is a potential candidate for development as a novel opioid for management of nociceptive, neuropathic and mixed pain states.
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PMID:Antinociceptive effects and toxicity of morphine-6-O-sulfate sodium salt in rat models of pain. 2082 49