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H. Ulrich Zeilhofer - One of the best experts on this subject based on the ideXlab platform.
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Selective Suppression of Inhibitory Synaptic Transmission by Nocistatin in the Rat Spinal Cord Dorsal Horn
2013Co-Authors: H. Ulrich Zeilhofer, Uta Muth-selbach, Hans Gühring, Katharina Erb, Seifollah AhmadiAbstract:Nociceptin/orphanin FQ (N/OFQ) and nocistatin (NST) are two recently identified neuropeptides with opposing effects on several CNS functions, including spinal Nociception. The cellular mechanisms that underlie this antagonism are not known. Here, we have investigated the effects of both peptides on synaptic transmission mediated by the three fast neurotransmitters L-glutamate, glycine, and GABA in the superficial layers of the rat spinal cord horn, which constitute the first important site of integration of nociceptive information in the pain pathway. NST selectively reduced transmitter release from inhibitory interneurons via a presynaptic Bordetella pertussis toxin-sensitive mechanism but left excitatory glutamatergic transmission unaffected. In contrast, N/OFQ only inhibited excitatory transmission. In the rat formalin test, an animal model of tonic pain in which N/OFQ exerts antinociceptive activity, NST induced profoun
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Modulation of synaptic transmission by nociceptin/orphanin FQ and nocistatin in the spinal cord dorsal horn of mutant mice lacking the nociceptin/orphanin FQ receptor.
Molecular pharmacology, 2001Co-Authors: Seifollah Ahmadi, Hiroshi Takeshima, Hans Gühring, Carolin E. Kotalla, Andreas Pahl, H. Ulrich ZeilhoferAbstract:Nociceptin/orphanin FQ (N/OFQ) and nocistatin (NST) are two neuropeptides derived from the same precursor protein that exhibit opposing effects on spinal neurotransmission and Nociception. Here, we have used whole-cell, patch-clamp recordings from visually identified neurons in spinal cord dorsal horn slices of genetically modified mice to investigate the role of the N/OFQ receptor (N/OFQ-R) in the modulatory action of both peptides on excitatory glutamatergic and inhibitory glycinergic and gamma-aminobutyric acid (GABA)-ergic synaptic transmission. In wild-type mice, N/OFQ selectively suppressed excitatory transmission in a concentration-dependent manner but left inhibitory synaptic transmission unaffected. In contrast, NST reduced only inhibitory but not alpha-amino-3-hydroxy-5-methylisoxazole-4-propionic acid (AMPA) receptor-mediated excitatory synaptic transmission. N/OFQ-mediated inhibition of excitatory transmission was completely absent in N/OFQ-R receptor-deficient (N/OFQ-R(-/-)) mice and significantly reduced in heterozygous (N/OFQ-R(+/-)) mice, whereas the action of NST on inhibitory neurotransmission was completely retained. To test for the relevance of these results for spinal Nociception, we investigated the effects of intrathecally injected N/OFQ in the mouse formalin test, an animal model of tonic pain. N/OFQ (3 nmol/mouse) induced significant antiNociception in wild-type mice, but had no antinociceptive effects in N/OFQ-R(-/-) mice. These results indicate that the inhibitory action of N/OFQ on excitatory glutamatergic synaptic transmission and its spinal antinociceptive action are mediated via the N/OFQ receptor, whereas the action of NST is independent of this receptor.
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modulation of synaptic transmission by nociceptin orphanin fq and nocistatin in the spinal cord dorsal horn of mutant mice lacking the nociceptin orphanin fq receptor
Molecular Pharmacology, 2001Co-Authors: Seifollah Ahmadi, Hiroshi Takeshima, H. Ulrich Zeilhofer, Hans Gühring, Carolin E. Kotalla, Andreas PahlAbstract:Nociceptin/orphanin FQ (N/OFQ) and nocistatin (NST) are two neuropeptides derived from the same precursor protein that exhibit opposing effects on spinal neurotransmission and Nociception. Here, we have used whole-cell, patch-clamp recordings from visually identified neurons in spinal cord dorsal horn slices of genetically modified mice to investigate the role of the N/OFQ receptor (N/OFQ-R) in the modulatory action of both peptides on excitatory glutamatergic and inhibitory glycinergic and gamma-aminobutyric acid (GABA)-ergic synaptic transmission. In wild-type mice, N/OFQ selectively suppressed excitatory transmission in a concentration-dependent manner but left inhibitory synaptic transmission unaffected. In contrast, NST reduced only inhibitory but not alpha-amino-3-hydroxy-5-methylisoxazole-4-propionic acid (AMPA) receptor-mediated excitatory synaptic transmission. N/OFQ-mediated inhibition of excitatory transmission was completely absent in N/OFQ-R receptor-deficient (N/OFQ-R(-/-)) mice and significantly reduced in heterozygous (N/OFQ-R(+/-)) mice, whereas the action of NST on inhibitory neurotransmission was completely retained. To test for the relevance of these results for spinal Nociception, we investigated the effects of intrathecally injected N/OFQ in the mouse formalin test, an animal model of tonic pain. N/OFQ (3 nmol/mouse) induced significant antiNociception in wild-type mice, but had no antinociceptive effects in N/OFQ-R(-/-) mice. These results indicate that the inhibitory action of N/OFQ on excitatory glutamatergic synaptic transmission and its spinal antinociceptive action are mediated via the N/OFQ receptor, whereas the action of NST is independent of this receptor.
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The role of the ORL1 receptor in the modulation of spinal neurotransmission by nociceptin/orphanin FQ and nocistatin.
European journal of pharmacology, 2001Co-Authors: Seifollah Ahmadi, Jörg T. Liebel, H. Ulrich ZeilhoferAbstract:Nociceptin/orphanin FQ and nocistatin are two neuropeptides with opposing effects on spinal neurotransmission and Nociception. Nociceptin/orphanin FQ selectively suppresses excitatory glutamatergic neurotransmission, while nocistatin selectively interferes with glycinergic and gamma-aminobutyric acid (GABA)-ergic transmission. Here, we performed whole-cell patch-clamp recordings from superficial rat spinal cord dorsal horn neurons to investigate the role of the opioid receptor-like (ORL)1 receptor for modulatory actions of these peptides. The partial ORL1 receptor antagonist [phe1psi(CH(2)-NH)Gly(2)]nociceptin-(1-13)NH(2) competitively reversed the effects of nociceptin/orphanin FQ on excitatory neurotransmission (estimated pA(2) 6.43), but left the suppression of inhibitory synaptic transmission by nocistatin unaffected. These results indicate that the inhibitory action of nociceptin/orphanin FQ on glutamatergic transmission is mediated via ORL1 receptors, while nocistatin acts via a different so far unidentified receptor.
Seifollah Ahmadi - One of the best experts on this subject based on the ideXlab platform.
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Selective Suppression of Inhibitory Synaptic Transmission by Nocistatin in the Rat Spinal Cord Dorsal Horn
2013Co-Authors: H. Ulrich Zeilhofer, Uta Muth-selbach, Hans Gühring, Katharina Erb, Seifollah AhmadiAbstract:Nociceptin/orphanin FQ (N/OFQ) and nocistatin (NST) are two recently identified neuropeptides with opposing effects on several CNS functions, including spinal Nociception. The cellular mechanisms that underlie this antagonism are not known. Here, we have investigated the effects of both peptides on synaptic transmission mediated by the three fast neurotransmitters L-glutamate, glycine, and GABA in the superficial layers of the rat spinal cord horn, which constitute the first important site of integration of nociceptive information in the pain pathway. NST selectively reduced transmitter release from inhibitory interneurons via a presynaptic Bordetella pertussis toxin-sensitive mechanism but left excitatory glutamatergic transmission unaffected. In contrast, N/OFQ only inhibited excitatory transmission. In the rat formalin test, an animal model of tonic pain in which N/OFQ exerts antinociceptive activity, NST induced profoun
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Modulation of synaptic transmission by nociceptin/orphanin FQ and nocistatin in the spinal cord dorsal horn of mutant mice lacking the nociceptin/orphanin FQ receptor.
Molecular pharmacology, 2001Co-Authors: Seifollah Ahmadi, Hiroshi Takeshima, Hans Gühring, Carolin E. Kotalla, Andreas Pahl, H. Ulrich ZeilhoferAbstract:Nociceptin/orphanin FQ (N/OFQ) and nocistatin (NST) are two neuropeptides derived from the same precursor protein that exhibit opposing effects on spinal neurotransmission and Nociception. Here, we have used whole-cell, patch-clamp recordings from visually identified neurons in spinal cord dorsal horn slices of genetically modified mice to investigate the role of the N/OFQ receptor (N/OFQ-R) in the modulatory action of both peptides on excitatory glutamatergic and inhibitory glycinergic and gamma-aminobutyric acid (GABA)-ergic synaptic transmission. In wild-type mice, N/OFQ selectively suppressed excitatory transmission in a concentration-dependent manner but left inhibitory synaptic transmission unaffected. In contrast, NST reduced only inhibitory but not alpha-amino-3-hydroxy-5-methylisoxazole-4-propionic acid (AMPA) receptor-mediated excitatory synaptic transmission. N/OFQ-mediated inhibition of excitatory transmission was completely absent in N/OFQ-R receptor-deficient (N/OFQ-R(-/-)) mice and significantly reduced in heterozygous (N/OFQ-R(+/-)) mice, whereas the action of NST on inhibitory neurotransmission was completely retained. To test for the relevance of these results for spinal Nociception, we investigated the effects of intrathecally injected N/OFQ in the mouse formalin test, an animal model of tonic pain. N/OFQ (3 nmol/mouse) induced significant antiNociception in wild-type mice, but had no antinociceptive effects in N/OFQ-R(-/-) mice. These results indicate that the inhibitory action of N/OFQ on excitatory glutamatergic synaptic transmission and its spinal antinociceptive action are mediated via the N/OFQ receptor, whereas the action of NST is independent of this receptor.
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modulation of synaptic transmission by nociceptin orphanin fq and nocistatin in the spinal cord dorsal horn of mutant mice lacking the nociceptin orphanin fq receptor
Molecular Pharmacology, 2001Co-Authors: Seifollah Ahmadi, Hiroshi Takeshima, H. Ulrich Zeilhofer, Hans Gühring, Carolin E. Kotalla, Andreas PahlAbstract:Nociceptin/orphanin FQ (N/OFQ) and nocistatin (NST) are two neuropeptides derived from the same precursor protein that exhibit opposing effects on spinal neurotransmission and Nociception. Here, we have used whole-cell, patch-clamp recordings from visually identified neurons in spinal cord dorsal horn slices of genetically modified mice to investigate the role of the N/OFQ receptor (N/OFQ-R) in the modulatory action of both peptides on excitatory glutamatergic and inhibitory glycinergic and gamma-aminobutyric acid (GABA)-ergic synaptic transmission. In wild-type mice, N/OFQ selectively suppressed excitatory transmission in a concentration-dependent manner but left inhibitory synaptic transmission unaffected. In contrast, NST reduced only inhibitory but not alpha-amino-3-hydroxy-5-methylisoxazole-4-propionic acid (AMPA) receptor-mediated excitatory synaptic transmission. N/OFQ-mediated inhibition of excitatory transmission was completely absent in N/OFQ-R receptor-deficient (N/OFQ-R(-/-)) mice and significantly reduced in heterozygous (N/OFQ-R(+/-)) mice, whereas the action of NST on inhibitory neurotransmission was completely retained. To test for the relevance of these results for spinal Nociception, we investigated the effects of intrathecally injected N/OFQ in the mouse formalin test, an animal model of tonic pain. N/OFQ (3 nmol/mouse) induced significant antiNociception in wild-type mice, but had no antinociceptive effects in N/OFQ-R(-/-) mice. These results indicate that the inhibitory action of N/OFQ on excitatory glutamatergic synaptic transmission and its spinal antinociceptive action are mediated via the N/OFQ receptor, whereas the action of NST is independent of this receptor.
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The role of the ORL1 receptor in the modulation of spinal neurotransmission by nociceptin/orphanin FQ and nocistatin.
European journal of pharmacology, 2001Co-Authors: Seifollah Ahmadi, Jörg T. Liebel, H. Ulrich ZeilhoferAbstract:Nociceptin/orphanin FQ and nocistatin are two neuropeptides with opposing effects on spinal neurotransmission and Nociception. Nociceptin/orphanin FQ selectively suppresses excitatory glutamatergic neurotransmission, while nocistatin selectively interferes with glycinergic and gamma-aminobutyric acid (GABA)-ergic transmission. Here, we performed whole-cell patch-clamp recordings from superficial rat spinal cord dorsal horn neurons to investigate the role of the opioid receptor-like (ORL)1 receptor for modulatory actions of these peptides. The partial ORL1 receptor antagonist [phe1psi(CH(2)-NH)Gly(2)]nociceptin-(1-13)NH(2) competitively reversed the effects of nociceptin/orphanin FQ on excitatory neurotransmission (estimated pA(2) 6.43), but left the suppression of inhibitory synaptic transmission by nocistatin unaffected. These results indicate that the inhibitory action of nociceptin/orphanin FQ on glutamatergic transmission is mediated via ORL1 receptors, while nocistatin acts via a different so far unidentified receptor.
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the role of the orl1 receptor in the modulation of spinal neurotransmission by nociceptin orphanin fq and nocistatin
European Journal of Pharmacology, 2001Co-Authors: Seifollah Ahmadi, Jörg T. Liebel, Ulrich H ZeilhoferAbstract:Nociceptin/orphanin FQ and nocistatin are two neuropeptides with opposing effects on spinal neurotransmission and Nociception. Nociceptin/orphanin FQ selectively suppresses excitatory glutamatergic neurotransmission, while nocistatin selectively interferes with glycinergic and gamma-aminobutyric acid (GABA)-ergic transmission. Here, we performed whole-cell patch-clamp recordings from superficial rat spinal cord dorsal horn neurons to investigate the role of the opioid receptor-like (ORL)1 receptor for modulatory actions of these peptides. The partial ORL1 receptor antagonist [phe1psi(CH(2)-NH)Gly(2)]nociceptin-(1-13)NH(2) competitively reversed the effects of nociceptin/orphanin FQ on excitatory neurotransmission (estimated pA(2) 6.43), but left the suppression of inhibitory synaptic transmission by nocistatin unaffected. These results indicate that the inhibitory action of nociceptin/orphanin FQ on glutamatergic transmission is mediated via ORL1 receptors, while nocistatin acts via a different so far unidentified receptor.
Hiroshi Ueda - One of the best experts on this subject based on the ideXlab platform.
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nsaid zaltoprofen possesses novel anti nociceptive mechanism through blockage of b2 type bradykinin receptor in nerve endings
Neuroscience Letters, 2006Co-Authors: Misaki Matsumoto, Makoto Inoue, Hiroshi UedaAbstract:Zaltoprofen, a propionic acid derivative of non-steroidal anti-inflammatory drugs (NSAIDs), was shown to have more powerful inhibitory effects to bradykinin (BK)-Nociception than other NSAIDs. However, the molecular mechanisms underlying this potent analgesia are not yet fully understood. Here we attempted to clarify the molecular mechanism underlying zaltoprofen-induced analgesia on BK-induced Nociception by a novel algogenic-induced paw flexion (APF) test in mice. The intraplantar (i.pl.) injection of zaltoprofen at 1nmol showed strong analgesic action on BK (i.pl.)-induced nociceptive flexor responses, whereas loxoprofen or its active metabolite loxoprofen-SRS did not. Zaltoprofen also inhibited the Nociception induced by [Tyr8]-BK, a specific agonist of B2-type BK receptor, but did not affect the Nociception by [Lys-des-Arg9]-BK, a specific agonist of B1-type BK receptor. However, zaltoprofen did not affect the substance P-induced Nociception, which is mediated by common post-receptor signaling through nociceptive fibers with BK-ones. All these results suggest that NSAID zaltoprofen possesses novel anti-nociceptive mechanism, which inhibits B2-type BK receptor function in nerve endings.
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nocistatin and prepro nociceptin orphanin fq 160 187 cause Nociception through activation of gi o in capsaicin sensitive and of gs in capsaicin insensitive nociceptors respectively
Journal of Pharmacology and Experimental Therapeutics, 2003Co-Authors: Makoto Inoue, Toshiko Kawashima, Richard G. Allen, Hiroshi UedaAbstract:Nociceptin/orphanin FQ (N/OFQ), nocistatin, and prepro-N/OFQ 160-187 (C-peptide) are all derived from the same precursor protein. We examine the pharmacological mechanisms of nocistatin- and C-peptide-induced pronociceptive responses in a novel algogenic-induced nociceptive flexion test in mice. The intraplantar (i.pl.) injection of nocistatin- and C-peptide induced pronociceptive responses in a range of 0.01 to 10 or 1 pmol, respectively, which showed 100- to 1000-fold less potent effects than the N/OFQ. The nociceptive effects of both peptides were not affected by 1-[(3R,4R)-1-cyclooctylmethyl-3-hydroxymethyl-4-piperidyl]-3-ethyl-1,3-dihydro-2H-benzimidazole-2-one (J-113397) (i.pl.), an N/OFQ receptor antagonist, indicating that they are mediated by a novel mechanism independent of activation of N/OFQ receptor. Like N/OFQ, nocistatin-induced Nociception was abolished by i.pl. injection of pertussis toxin, phospholipase C inhibitor, or CP-99994, a neurokinin 1 receptor antagonist, indicating that nocistatin may elicit Nociception through a substance P release from nociceptor endings via activation of Gi/o and phospholipase C. The Nociception was abolished by neonatal pretreatment (s.c.) with capsaicin or by i.t. pretreatment with CP-99994, but not MK-801 (i.t.), an N-methyl-d-aspartate receptor antagonist. In contrast, C-peptide-induced Nociception was attenuated by the pretreatment with antisense oligodeoxynucleotide for Galphas (i.t.) and with KT-5720 (i.pl.), a cyclic AMP-dependent protein kinase inhibitor, but not with pertussis toxin. The Nociception was neither attenuated by neonatal capsaicin nor by i.t. injection with CP-99994, but it was attenuated by i.t. injection with MK-801. These results suggest that nocistatin and C-peptide derived from prepro-N/OFQ stimulate distinct nociceptive fibers through different in vivo signaling mechanisms.
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Nocistatin and Prepro-Nociceptin/Orphanin FQ 160–187 Cause Nociception through Activation of Gi/o in Capsaicin-Sensitive and of Gs in Capsaicin-Insensitive Nociceptors, Respectively
The Journal of pharmacology and experimental therapeutics, 2003Co-Authors: Makoto Inoue, Toshiko Kawashima, Richard G. Allen, Hiroshi UedaAbstract:Nociceptin/orphanin FQ (N/OFQ), nocistatin, and prepro-N/OFQ 160-187 (C-peptide) are all derived from the same precursor protein. We examine the pharmacological mechanisms of nocistatin- and C-peptide-induced pronociceptive responses in a novel algogenic-induced nociceptive flexion test in mice. The intraplantar (i.pl.) injection of nocistatin- and C-peptide induced pronociceptive responses in a range of 0.01 to 10 or 1 pmol, respectively, which showed 100- to 1000-fold less potent effects than the N/OFQ. The nociceptive effects of both peptides were not affected by 1-[(3R,4R)-1-cyclooctylmethyl-3-hydroxymethyl-4-piperidyl]-3-ethyl-1,3-dihydro-2H-benzimidazole-2-one (J-113397) (i.pl.), an N/OFQ receptor antagonist, indicating that they are mediated by a novel mechanism independent of activation of N/OFQ receptor. Like N/OFQ, nocistatin-induced Nociception was abolished by i.pl. injection of pertussis toxin, phospholipase C inhibitor, or CP-99994, a neurokinin 1 receptor antagonist, indicating that nocistatin may elicit Nociception through a substance P release from nociceptor endings via activation of Gi/o and phospholipase C. The Nociception was abolished by neonatal pretreatment (s.c.) with capsaicin or by i.t. pretreatment with CP-99994, but not MK-801 (i.t.), an N-methyl-d-aspartate receptor antagonist. In contrast, C-peptide-induced Nociception was attenuated by the pretreatment with antisense oligodeoxynucleotide for Galphas (i.t.) and with KT-5720 (i.pl.), a cyclic AMP-dependent protein kinase inhibitor, but not with pertussis toxin. The Nociception was neither attenuated by neonatal capsaicin nor by i.t. injection with CP-99994, but it was attenuated by i.t. injection with MK-801. These results suggest that nocistatin and C-peptide derived from prepro-N/OFQ stimulate distinct nociceptive fibers through different in vivo signaling mechanisms.
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enhanced spinal nociceptin receptor expression develops morphine tolerance and dependence
The Journal of Neuroscience, 2000Co-Authors: Hiroshi Ueda, Hiroshi Takeshima, Makoto Inoue, Yoshikazu IwasawaAbstract:The tolerance and dependence after chronic medication with morphine are thought to be representative models for studying the plasticity, including the remodeling of neuronal networks. To test the hypothesis that changes in neuronal plasticity observed in opioid tolerance or dependence are derived from increased activity of the anti-opioid nociceptin system, the effects of chronic treatments with morphine were examined using nociceptin receptor knock-out (NOR−/−) mice and a novel nonpeptidic NOR antagonist, J-113397, which shows a specific and potent NOR antagonist activity in in vitro [35S]GTPγS binding assay and in vivo peripheral Nociception test. The NOR−/− mice showed marked resistance to morphine analgesic tolerance without affecting morphine analgesic potency in tail-pinch and tail-flick tests. The NOR−/− mice also showed marked attenuation of morphine-induced physical dependence, manifested as naloxone-precipitated withdrawal symptoms after repeated morphine treatments. Similar marked attenuation of morphine tolerance was also observed by single subcutaneous (10 mg/kg) or intrathecal (1 nmol) injection of J-113397, which had been given 60 min before the test in morphine-treated ddY mice. However, the intracerebroventricular injection (up to 3 nmol) did not affect the tolerance. On the other hand, morphine dependence was markedly attenuated by J-113397 that had been subcutaneously given 60 min before naloxone challenge. There was also observed a parallel enhancement of NOR gene expression only in the spinal cord during chronic morphine treatments. Together, these findings suggest that the spinal NOR system develops anti-opioid plasticity observed on morphine tolerance and dependence.
Sanzio Candeletti - One of the best experts on this subject based on the ideXlab platform.
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Nociceptin/orphanin FQ prevents the antinociceptive action of paracetamol on the rat hot plate test.
European Journal of Pharmacology, 2005Co-Authors: Maurizio Sandrini, Giuseppe Lopetuso, Patrizia Romualdi, Giovanni Vitale, Luigi Alberto Pini, Sanzio CandelettiAbstract:Abstract Nociceptin/orphanin FQ (N/OFQ) is involved in many behavioural patterns; in particular, it exerts a modulating effect on Nociception. Like other proposed antiopiates, nociceptin/orphanin FQ has been shown to have analgesic, hyperalgesic as well as antianalgesic properties. Among the various effects proposed on nociceptive sensitivity at supraspinal level, the antagonistic activity toward morphine analgesia seems to be of interest. Therefore, we decided to investigate whether nociceptin/orphanin FQ and [Arg 14 , Lys 15 ] nociceptin/orphanin FQ (R-K, a nociceptin analogue) can have the same effect on the analgesia produced by nonopioid analgesics. In this study, we examined the antianalgesic effect of nociceptin/orphanin FQ and its analogue R-K on paracetamol-induced analgesia and evaluated by means of the hot plate test in rats. Nociceptin/orphanin FQ was intracerebroventricularly administered, and, after 5 min, a dose of 400 mg/kg paracetamol was injected intraperitoneally, 30 min before the hot plate test. Nociceptin/orphanin FQ and R-K showed a dose-dependent antagonism on the antinociceptive effect of paracetamol, and the activity of both drugs was significantly reduced by the antagonist [Nphe 1 ] Arg 14 , Lys 15 –N/OFQ–NH 2 (UFP-101). These data indicate that nociceptin/orphanin FQ and R-K have an antianalgesic effect on the analgesia produced by a nonopioid analgesic drug, like paracetamol, that seems to develop within the brain.
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nociceptin orphanin fq prevents the antinociceptive action of paracetamol on the rat hot plate test
European Journal of Pharmacology, 2005Co-Authors: Maurizio Sandrini, Giuseppe Lopetuso, Patrizia Romualdi, Giovanni Vitale, Luigi Alberto Pini, Sanzio CandelettiAbstract:Nociceptin/orphanin FQ (N/OFQ) is involved in many behavioural patterns; in particular, it exerts a modulating effect on Nociception. Like other proposed antiopiates, nociceptin/orphanin FQ has been shown to have analgesic, hyperalgesic as well as antianalgesic properties. Among the various effects proposed on nociceptive sensitivity at supraspinal level, the antagonistic activity toward morphine analgesia seems to be of interest. Therefore, we decided to investigate whether nociceptin/orphanin FQ and [Arg14, Lys15] nociceptin/orphanin FQ (R-K, a nociceptin analogue) can have the same effect on the analgesia produced by nonopioid analgesics. In this study, we examined the antianalgesic effect of nociceptin/orphanin FQ and its analogue R-K on paracetamol-induced analgesia and evaluated by means of the hot plate test in rats. Nociceptin/orphanin FQ was intracerebroventricularly administered, and, after 5 min, a dose of 400 mg/kg paracetamol was injected intraperitoneally, 30 min before the hot plate test. Nociceptin/orphanin FQ and R-K showed a dose-dependent antagonism on the antinociceptive effect of paracetamol, and the activity of both drugs was significantly reduced by the antagonist [Nphe1] Arg14, Lys15-N/OFQ-NH2 (UFP-101). These data indicate that nociceptin/orphanin FQ and R-K have an antianalgesic effect on the analgesia produced by a nonopioid analgesic drug, like paracetamol, that seems to develop within the brain.
Lawrence Toll - One of the best experts on this subject based on the ideXlab platform.
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Small-molecule agonists and antagonists of the opioid receptor-like receptor (ORL1, NOP): ligand-based analysis of structural factors influencing intrinsic activity at NOP.
The AAPS journal, 2005Co-Authors: Nurulain Zaveri, Faming Jiang, Cris Olsen, Willma Polgar, Lawrence TollAbstract:The recently discovered fourth member of the opioid receptor family, the nociceptin receptor (NOP) and its endogenous ligand, the heptadecapeptide nociceptin, are involved in several central nervous system pathways, such as Nociception, reward, tolerance, and feeding. The discovery of small-molecule ligands for NOP is being actively pursued for several therapeutic applications. This review presents a brief overview of the several recently reported NOP ligands, classified as NOP agonists and antagonists, with an emphasis on the analysis of the structural features that may be important for modulating the agonist/antagonist profile (intrinsic activity) of these ligands. Structure-activity relationships in our own series of dihydroindolinone-based NOP ligands and those of the various reported ligands indicate that the lipophilic substituent on the common basic nitrogen present in all NOP ligands plays a role in determining the agonist/antagonist profile of the NOP ligand. This analysis provides a basis for the rational drug design of NOP ligands of desired intrinsic activity and provides a framework for developing pharmacophore models for high affinity binding and intrinsic activity at the NOP receptor. Since NOP agonists and antagonists both have therapeutic value, rational approaches for obtaining both within a high-affinity binding class of compounds are very useful for designing potent and selective NOP ligands with the desired profile of intrinsic efficacy.
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Small-molecule agonists and antagonists of the opioid receptor-like receptor (ORL1, NOP): ligand-based analysis of structural factors influencing intrinsic activity at NOP.
Aaps Journal, 2005Co-Authors: Nurulain T. Zaveri, Faming Jiang, Cris M. Olsen, Willma E. Polgar, Lawrence TollAbstract:The recently discovered fourth member of the opioid receptor family, the nociceptin receptor (NOP) and its endogenous ligand, the heptadecaptide nociceptin, are involved in several central nervous system pathways, such as Nociception, reward, tolerance, and feeding. The discovery of small-molecule ligands for NOP is being actively pursued for several therapeutic applications. This review presents a brief overview of the several recently reported NOP ligands, classified as NOP agonists and antagonists, with an emphasis on the analysis of the structural features that may be important for modulating the agonist/antagonist profile (intrinsic activity) of these ligands. Structure-activity relationships in our own series of dihydroindolinone-based NOP ligands and those of the various reported ligands indicate that the lipophilic substituent on the common basic nitrogen present in all NOP ligands plays a role in determining the agonist/antagonist profile of the NOP ligand. This analysis provides a basis for the rational drug design of NOP ligands of desired intrinsic activity and provides a framework for developing pharmacophore models for high affinity binding and intrinsic activity at the NOP receptor. Since NOP agonists and antagonists both have therapeutic value, rational approaches for obtaining both within a high-affinity binding class of compounds are very useful for designing potent and selective NOP ligands with the desired profile of intrinsic efficacy.
