Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0344307 (analgesia)
 28,200 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The effects of beta-chlornaltrexamine (CNA, 5 mg/kg s.c.) on social conflict analgesia and brain opioid binding were investigated in mice at different times after the administration of the alkylating antagonist. The specific binding of [3H]etorphine to high-affinity binding sites and the stress-induced analgesia of attacked mice (50 bites) were prevented for 6 h after CNA administration. Stress-mediated inhibition of pain fully recovered within 3 days after CNA treatment. Brain opioid binding was still reduced to 45% at this time and reached control values 9 days after treatment.
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PMID:Recovery from opioid receptor alkylation: social conflict analgesia and brain [3H]etorphine binding in beta-chlornaltrexamine-treated mice. 285 70

Chlornaltrexamine (beta-CNA) a selective, long-acting irreversible opiate antagonist inhibited the analgesia, hypothermia, hypothermia tolerance and physical dependence produced by delta 9-tetrahydrocannabinol (THC) in rats. The results suggest that there are some common features between cannabis and opiates and some actions of THC may be mediated by opioid related mechanisms in the central nervous system.
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PMID:Antagonism by chlornaltrexamine of some effects of delta 9-tetrahydrocannabinol in rats. 626 44

Experiments were conducted to test the in vivo opiate specificity and long-lasting effects of two non-equilibrium opiate antagonists: beta-chlornaltrexamine (beta-CNA) and the beta-fumarate methyl ester derivative of naltrexone (beta-FNA). beta-CNA (2.5 or 5.0 micrograms, ICV) partially antagonized suppression of conditioned autoshaped behavior by morphine, when morphine was administered 48-72 hr after beta-CNA. beta-CNA had no effect on amphetamine-induced suppression of autoshaped responding, nor did it antagonize the suppression in rearing activity induced by either morphine or amphetamine. Similarly, beta-FNA (5 mg/kg, IP) antagonized the suppression of conditioned behavior by morphine, for up to 48 hr, while having no effect on amphetamine-induced suppression of autoshaped responding, or on the suppression of rearing activity induced by morphine or amphetamine. Further peripherally administered beta-FNA acts in the brain, since it antagonized analgesia following ICV morphine administration.
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PMID:Antagonism of morphine-induced behavioral suppression by opiate receptor alkylators. 628 Feb 6

The long-acting opiate antagonistic potency of naloxazone (NXZ), beta-chlornaltrexamine (beta-CNA) and beta-funaltrexamine (beta-FNA) was compared using three inbred strains of mice, in which morphine induces either analgesia (DBA/2), locomotion (C57BL/6), or both responses (C3H/He). The antagonists were applied SC 24-120 hr before morphine (10 or 20 mg/kg, IP), followed by the tests after 30 min. The minimal dose which completely antagonized morphine-induced analgesia in DBA and locomotion in C57 mice during 24 hr were: for NXZ 50 and 100 mg/kg, for beta-CNA 0.8 and 6.2 mg/kg, for beta-FNA 1.6 and 12.5 mg/kg, respectively. beta-FNA and beta-CNA more potently blocked morphine-induced analgesia in DBA mice than the activity response in the C57 strain. In contrast, beta-FNA prevented morphine-induced locomotion at a lower dose (6.2 mg/kg) than analgesia (greater than 50 mg/kg) in C3H mice, while beta-CNA was equipotent (1.6 mg/kg). In general, beta-CNA turned out to be the most reactive compound, antagonizing morphine effects in low doses up to 120 hr. beta-FNA selectively antagonized either morphine-induced analgesia or locomotion, depending on the strain used. This suggests that a given morphine response might be caused by a genetically determined multiplicity of opiate receptor types and their mutual interactions.
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PMID:Inhibition of morphine-induced analgesia and locomotor activity in strains of mice: a comparison of long-acting opiate antagonists. 665 26

We observed that the spinal cord of rats was involved in development of tolerance and dependence to morphine that was administered systemically by s.c. morphine-pellet implantation. Rats, surgically fitted with intrathecal catheters, were injected intrathecally (i.t.) with saline or 2.4 nmol beta-chlornaltrexamine (beta-CNA), an irreversible opiate antagonist. Twenty-four h later, animals were implanted s.c. with either placebo or morphine pellets. Seventy-two h after implanting pellets, development of tolerance or dependence was assessed. Control animals implanted with morphine pellets became tolerant to analgesia induced by i.p. injections of morphine as determined by the use of tail flick and hot plate analgesic assays. beta-CNA pretreatment antagonized the effects of i.p. injections of morphine and blocked development of tolerance in morphine-implanted animals. Dependence was assessed by observing several characteristic signs of precipitated withdrawal. Treatment with beta-CNA before morphine treatment antagonized naloxone-induced expression of withdrawal for all signs observed, except weight loss. We conclude that the spinal cord plays a significant role in development of tolerance and dependence induced by systemically administered opiates.
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PMID:Spinal antagonism of tolerance and dependence induced by systemically administered morphine. 668 42