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

The effect of morphine treatment on cholecystokinin (CCK) receptor binding in rat cerebral cortex was investigated. Subcutaneous implantation and removal of Alzet miniosmotic pumps, releasing morphine, permitted us to establish the phases of initial analgesia, tolerance to the analgesic action of morphine, morphine withdrawal and abstinence. CCK receptor binding in rat cerebral cortex never differed from the values obtained from animals implanted with saline-releasing minipumps. The results of the present study suggest that the putative changes in the interaction between opioidergic and CCKergic neurotransmission at different stages of morphine treatment and withdrawal are not caused by changes of CCK receptor binding properties.
 ...
PMID:Cholecystokinin receptor binding in morphine analgesia: tolerance, withdrawal and abstinence. 793 25

Cholecystokinin (CCK) has emerged as an important mammalian neuropeptide, localized in peripheral organs and in the central nervous system. This review presents an overview of the molecular aspects of CCK peptides and CCK receptors, the anatomical distribution of CCK, the neurophysiological actions of CCK, release of CCK and effects of CCK on release of other neurotransmitters, and the actions of CCK on digestion, feeding, cardiovascular function, respiratory function, neurotoxicity and seizures, cancer cell proliferation, analgesia, sleep, sexual and reproductive behaviors, memory, anxiety, and dopamine-mediated exploratory and rewarded behaviors. Human clinical studies of CCK in feeding disorders and panic disorders are described. New findings are presented on potent, nonpeptide CCK antagonists, selective for the two CCK receptor subtypes, which demonstrate that endogenous CCK has biologically important effects on physiology and behavior.
 ...
PMID:Biological actions of cholecystokinin. 793 54

Published results suggest that delta-opioid agonists can modulate the mu-mediated analgesia. In this work, the antinociceptive effects produced by the mu agonist [D-Ala2,NMe-Phe4,Gly-ol5]enkephalin or the mixed inhibitor of enkephalin-degrading enzymes RB 101 (N- [(R,S)-2-benzyl-3[(S)(2-amino-4-methyl- thio)butyldithio]-1-oxopropyl]-L-phenylalanine benzyl ester) were studied after administration of the systemically active and selective delta agonist Tyr-D-Ser(O-tert-butyl)-Gly-Phe-Leu- Thr(O-tert-butyl). In the hot-plate test in mice, Tyr-D-Ser(O-tert-butyl)-Gly- Phe-Leu-Thr(O-tert-butyl) (i.v.) potentiated the antinociceptive responses elicited by [D-Ala2,NMe-Phe4,Gly-ol5]enkephalin (i.v.) or RB 101 (i.v.). These facilitatory effects were reversed not only by prior administration of the delta-selective antagonist naltrindole (0.5 mg/kg s.c.), but also unexpectedly by the selective cholecystokinin CCK-A antagonist MK-329 (20 micrograms/kg i.p.). In addition, the CCK analog [Boc- Tyr(SO3H)-Nle-Gly-Trp-Nle-Asp-Phe-NH2] (a mixed CCK-A/CCK-B agonist) increased the jump latency and this effect was blocked by MK-329 (20 micrograms/kg i.p.) and by naloxone, but not by the selective CCK-B antagonist L-365,260 (5 mg/kg i.p.). In contrast, the selective CCK-B agonist BC 264 (62 micrograms/kg i.v.) produced a hyperalgesic effect that was antagonized by L-365,260 (5 mg/kg i.p.). Taken together, these findings suggest that the potentiating effects of delta agonists on mu-mediated analgesia are due to an increase in the release of endogenous CCK interacting with CCK-A and CCK-B receptors and resulting in positive and negative regulation of the endogenous opioid system.(ABSTRACT TRUNCATED AT 250 WORDS)
 ...
PMID:Role of endogenous cholecystokinin in the facilitation of mu-mediated antinociception by delta-opioid agonists. 799 17

The periaqueductal gray (PAG) is an important integration site for pain, autonomic functions, vocalization, fear and anxiety. Cholecystokinin (CCK) is a major neurotransmitter in the PAG and CCK receptors are heterogeneously distributed within the PAG. Since CCK antagonists are anxiolytic and potentiate morphine analgesia, it is possible that these effects of CCK are mediated through alteration of neuronal activities in the PAG. The goals of this study were to examine the anatomical and physiological properties of the PAG CCK containing systems. The distribution of CCK-containing axons and boutons in PAG was examined using immunohistochemical procedures. These studies show that CCK-like immunoreactive (CCK-LIR) fibers and terminals are present throughout PAG, but are particularly heavily concentrated in a focal column that runs longitudinally throughout the rostrocaudal axis of dorsolateral PAG and in nucleus cuneiformis which represents a caudolateral extension of PAG. The physiological effects of CCK on PAG neurons were examined in both in vivo and in vitro preparations. In the in vivo experiments multibarreled electrodes were used to record from PAG neurons and to apply CCK and the CCK antagonists, CR1409 and proglumide. Of 37 neurons recorded in vivo, CCK caused excitation in 25 cells, inhibited 7 cells and had no effect on 5 cells. The excitatory effect was blocked by CR1409 in 11/11 cells tested. Proglumide blocked the excitatory response of CCK in 12/14 cells. Proglumide blocked the inhibitory effect in 2 of 7 cells, but CR1409 had no effect on CCK-evoked inhibition in 7 cells tested. Extracellular, conventional intracellular and whole cell patch clamping procedures were used to study CCK actions in the in vitro slice preparation. In the extracellular recording experiments, responses of PAG cells to CCK were measured in slices that were maintained at 22 degrees C (room temperature) and at 32 degrees C. CCK excited 40/56, inhibited 7/56 and had no effect on 9/56 cells; excitatory responses were blocked by CR1409 in 32/36 cells and by proglumide in 25/27 cells tested. Inhibitory responses to CCK were unaffected by CR1409, but were blocked in 3/7 cells by proglumide. Conventional intracellular recordings were made from 13 cells.(ABSTRACT TRUNCATED AT 400 WORDS)
 ...
PMID:Characterization of the effect of cholecystokinin (CCK) on neurons in the periaqueductal gray of the rat: immunocytochemical and in vivo and in vitro electrophysiological studies. 803 4

The central nervous system contains circuitry that inhibits pain sensitivity (analgesia), as well as circuitry that opposes pain inhibition (anti-analgesia). Activation of analgesia systems and anti-analgesia systems can each be brought under environmental control using classical conditioning procedures. Analgesia can be produced by cues present before and during aversive events such as electric shock, while active inhibition of analgesia comes to be produced by cues never present immediately before or during shock and therefore signal safety. We have recently reported that these analgesia and anti-analgesia systems interact at the level of the spinal cord. A series of 3 experiments were performed to examine how such interactions occur. First, potential opioid mediation of conditioned analgesia was investigated using systemic and intrathecal (i.t.) delivery of opiate antagonists. Conditioned analgesia was found to be mediated by activation of spinal mu and delta opiate receptors. Second, analgesia produced by each of these receptor subtypes was challenged by environmental signals for safety. Analgesias produced by mu and delta opiate agonists were each abolished by safety signals. Third, antagonists/antisera directed against several putative anti-opiate neurotransmitters were tested i.t. to identify which mediate conditioned anti-analgesia at the level of the spinal cord. A cholecystokinin antagonist abolished conditioned anti-analgesia. In contrast, neuropeptide FF antiserum and a kappa opiate antagonist were without effect.
 ...
PMID:The nature of conditioned anti-analgesia: spinal cord opiate and anti-opiate neurochemistry. 813 Oct 71

A [125I]cholecystokinin (CCK) analog and [125I]peptide YY (PYY) were used to localize and characterize CCK and neuropeptide Y (NPY) receptor binding sites in the rabbit vagal afferent (nodose) ganglion. High concentrations of CCK and NPY binding sites were observed in 10.6% and 9.2% of the nodose ganglion neurons, respectively. Pharmacological experiments using CCK or NPY analogs suggest that both subtypes of CCK (CCK-A and CCK-B) and NPY (Y1 and Y2) receptor binding sites are expressed by discrete populations of neurons in the nodose ganglion. These results suggest sites at which CCK or NPY, released in either the nucleus of the solitary tract or a peripheral tissue, may modulate the release of neurotransmitters from a select population of visceral primary afferent neurons. Possible functions mediated by these receptors include modulation of satiety, opiate analgesia, and the development of morphine tolerance.
 ...
PMID:Cholecystokinin and neuropeptide Y receptors on single rabbit vagal afferent ganglion neurons: site of prejunctional modulation of visceral sensory neurons. 813 66

Previous studies have shown that repeated opioid administration induces a tolerance to opioid, presumably due in part to an opioid-mediated compensatory increase in brain cholecystokinin (CCK) synthesis and/or release. In this study, in situ hybridization histochemistry was used to examine the effect of morphine tolerance on CCK gene expression in the amygdala of rat brains, by using a 35S-labeled synthetic oligonucleotide probe. CCK mRNA-positive neurons in normal rats were seen throughout the amygdaloid complex, with the most heavily labeled neurons in lateral, basal, and cortical nuclei, followed by the medial nucleus. Only a few labeled neurons were found in central and intercalated nuclei. The development of morphine tolerance in the rat was associated with increased hybridization signals for CCK mRNA in each subnucleus of the amygdala. Increases were seen in the numbers of positively labeled neurons and/or the numbers of hybridization grains per positively labeled neuron. Furthermore, differential patterns of increase in CCK mRNA in morphine tolerant rats occurred in different subnuclei of the amygdala, with the highest magnitude of increase in the cortical nucleus, followed in order by the medial, central, basal, intercalated and lateral nuclei. The present study demonstrated that repeated administration of morphine increased CCK gene expression in the amygdaloid complex, and suggested that the development of the tolerance to morphine analgesia is due, in part, to an increase in CCK activity in the amygdaloid complex. These findings substantiate the hypothesis that long-term administration of opioid may induce a compensatory increase in CCK synthesis and/or release, which then results in a progressive antagonism of opioid analgesia.
 ...
PMID:Cholecystokinin gene expression in rat amygdaloid neurons: normal distribution and effect of morphine tolerance. 817 Mar 43

The antagonistic effect on opioid analgesia of central cholecystokinin octapeptide (CCK-8) has been amply demonstrated by behavioral and electrophysiological studies, although the mechanisms of action remain obscure. Since the phosphatidylinositol (PI) system is known to be involved in CCK effects in pancreatic tissue, and lithium has been shown to interfere with PI turnover, we sought to investigate whether LiCl would block the antiopioid effect of CCK-8 in the CNS. Nociceptive thresholds were assessed by the latency of the tail flick response (TFL). Intrathecal injection (ith) of LiCl at 4 cumulative doses (1.25-25 mumol) produced no significant change in the baseline TFL, nor was the antinociceptive effect induced by ohmefentanyl (OMF, the mu-selective opioid agonist, 20 ng, ith) reversed by LiCl. However, OMF-induced antinociception was dose-dependently reversed by CCK-8 (1-16 ng, ith), which alone at 5 cumulative doses (1-20 ng) had no influence on TFL, and the reversal effect of CCK-8 could be readily antagonized by LiCl (0.6-20 mumol, ith). The results are interpreted to mean that the PI signal system may play an important role in mediating the antiopioid effect of CCK-8.
 ...
PMID:Regulation by lithium of the antagonistic effect of cholecystokinin octapeptide on ohmefentanyl-induced antinociception. 818 36

Cholecystokinin octapeptide (CCK-8) has been shown to be a neuropeptide with potent anti-opioid activity. Previous studies have shown that central administration of nanogram dose of CCK-8 totally abolished morphine analgesia in the rat, an effect mediated by CCK-B receptor in central nervous system. In the present study CCK-B antagonist L-365,260 was injected intracerebroventricularly (icv) to Wistar rats to see its effect on the analgesic effect induced by electroacupuncture (EA) stimulation. A marked potentiation of EA-induced analgesia was observed. The degree of potentiation depends on the frequency of EA used, with a rank order of 100 Hz > 15 Hz = 2/15 Hz > > 2 Hz. In a strain of rat with acoustically evoked epileptic seizure (P77PMC rats), an extra-ordinarily strong analgesic effect was produced in response to 100 Hz EA stimulation, which was similar to that in Wistar rats pre-treated with L-365,260. However, L-365,260 was not effective in potentiating EA analgesia in P77PMC rats. The results suggest that (1) high frequency EA is more likely to increase the release of CCK-8 in CNS as compared to low frequency EA, and (2) P77PMC rats may have a functional defect of the central CCK neurons in the nature of either a low CCK content or a reduced rate of release of CCK-8 in the CNS.
 ...
PMID:CCK receptor antagonist L-365,260 potentiated electroacupuncture analgesia in Wistar rats but not in audiogenic epileptic rats. 819 76

The effects of intracerebroventricular administration of the cholecystokinin (CCK) analogue, BDNL, and the selective CCK-B agonist, BC 264, were determined using the hot plate test in mice. BDNL (0.2 nmol and 0.5 nmol) increased the jump and the paw lick latencies. These effects were blocked by the CCK-A antagonist MK-329 (0.02 mg/kg), supporting the involvement of CCK-A receptors in CCK-induced analgesia. In contrast, the selective CCK-B agonist BC 264 produced, at one dose (2.5 nmol), a slight decrease in the lick latency that was only antagonized by the CCK-B antagonist. Naloxone, but not naltrindole, antagonized BDNL-induced analgesia. The results suggest that activation of CCK-A receptors by BDNL leads to antinociceptive responses indirectly mediated by stimulation of mu-opioid receptors by endogenous enkephalins.
 ...
PMID:Cholecystokinin-A but not cholecystokinin-B receptor stimulation induces endogenous opioid-dependent antinociceptive effects in the hot plate test in mice. 824 53


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>