The Experts below are selected from a list of 267291 Experts worldwide ranked by ideXlab platform

Xiao-jun Xu - One of the best experts on this subject based on the ideXlab platform.

  • Analgesic effect of sinomenine in rodents after Inflammation and nerve injury.
    European journal of pharmacology, 2013
    Co-Authors: Zsuzsanna Wiesenfeld-hallin, Dan-qiao Wang, Xiao-jun Xu
    Abstract:

    Sinomenine is an alkaloid originally isolated from the root of the plant Sinomenium acutum. It is used in traditional medicine in China to treat rheumatic arthritis. In the present study, we evaluated the potential antinociceptive effects of sinomenine in rodents with nociceptive, inflammatory and neuropathic pain. In normal rats and mice, systemic sinomenine produced moderate antinociceptive effect in the hot plate and tail flick tests. Sinomenine also exerted analgesic effects on mechanical and heat hypersensitivity in mice after carrageenan induced Inflammation. Finally, sinomenine effectively alleviated mechanical and cold allodynia in rats and mice after injury to peripheral nerve or spinal cord. The analgesic effect of sinomenine is not associated with side effects and is not reversed by the opioid receptor antagonist naloxone. Our results showed that sinomenine has a wide spectrum analgesic effect in rodent models of nociceptive, inflammatory and neuropathic pain.

  • effects of intrathecal orphanin fq on a flexor reflex in the rat after Inflammation or peripheral nerve section
    European Journal of Pharmacology, 1999
    Co-Authors: Isabella S Xu, Stefan Grass, Z Wiesenfeldhallin, Xiao-jun Xu
    Abstract:

    We examined the effects of intrathecal orphanin FQ, the endogenous ligand for the orphan opioid-like receptor, on the hamstring nociceptive flexor reflex in decerebrate, spinalized, unanesthetized rats after Carrageenan-Induced Inflammation or unilateral sciatic nerve transection. As described previously [Xu, X.-J., Hao, J.-X., Wiesenfeld-Hallin, Z., 1996. Orphanin FQ or antiorphanin FQ: potent spinal antinociceptive effect of orphanin FQ/orphanin FQ in the rat. NeuroReport 7, 2092–2094.], intrathecal orphanin FQ induced a dose-dependent depression of the flexor reflex with a ED50 of 965 ng. Initial reflex facilitation was noted in some experiments at lower doses (10 or 100 ng). A similar bi-phasic response pattern to intrathecal orphanin FQ was observed in experiments conducted in inflamed or axotomized rats. However, the magnitude of the initial reflex facilitation was significantly increased in inflamed rats compared to normals whereas the duration of reflex depression was significantly shortened. The ED50 for reflex depression was 2.4 μg for inflamed rats. In contrast, axotomy did not significantly alter the facilitatory and depressive effect of orphanin FQ with ED50 for reflex depression being 374 ng. These results confirmed an inhibitory action of orphanin FQ on spinal nociception in rats. It is suggested that the effect of orphanin FQ may be modulated by Inflammation and nerve injury. In particular, unlike morphine, there seems to be no reduction in the effect of spinal orphanin FQ in inducing antinociception after peripheral nerve axotomy.

  • effects of intrathecal orphanin fq on a flexor reflex in the rat after Inflammation or peripheral nerve section
    European Journal of Pharmacology, 1999
    Co-Authors: Isabella S Xu, Stefan Grass, Zsuzsanna Wiesenfeldhallin, Xiao-jun Xu
    Abstract:

    We examined the effects of intrathecal orphanin FQ, the endogenous ligand for the orphan opioid-like receptor, on the hamstring nociceptive flexor reflex in decerebrate, spinalized, unanesthetized rats after Carrageenan-Induced Inflammation or unilateral sciatic nerve transection. As described previously [Xu, X.-J., Hao, J.-X., Wiesenfeld-Hallin, Z., 1996. Orphanin FQ or antiorphanin FQ: potent spinal antinociceptive effect of orphanin FQ/orphanin FQ in the rat. NeuroReport 7, 2092–2094.], intrathecal orphanin FQ induced a dose-dependent depression of the flexor reflex with a ED50 of 965 ng. Initial reflex facilitation was noted in some experiments at lower doses (10 or 100 ng). A similar bi-phasic response pattern to intrathecal orphanin FQ was observed in experiments conducted in inflamed or axotomized rats. However, the magnitude of the initial reflex facilitation was significantly increased in inflamed rats compared to normals whereas the duration of reflex depression was significantly shortened. The ED50 for reflex depression was 2.4 μg for inflamed rats. In contrast, axotomy did not significantly alter the facilitatory and depressive effect of orphanin FQ with ED50 for reflex depression being 374 ng. These results confirmed an inhibitory action of orphanin FQ on spinal nociception in rats. It is suggested that the effect of orphanin FQ may be modulated by Inflammation and nerve injury. In particular, unlike morphine, there seems to be no reduction in the effect of spinal orphanin FQ in inducing antinociception after peripheral nerve axotomy.

Isabella S Xu - One of the best experts on this subject based on the ideXlab platform.

  • effects of intrathecal orphanin fq on a flexor reflex in the rat after Inflammation or peripheral nerve section
    European Journal of Pharmacology, 1999
    Co-Authors: Isabella S Xu, Stefan Grass, Zsuzsanna Wiesenfeldhallin, Xiao-jun Xu
    Abstract:

    We examined the effects of intrathecal orphanin FQ, the endogenous ligand for the orphan opioid-like receptor, on the hamstring nociceptive flexor reflex in decerebrate, spinalized, unanesthetized rats after Carrageenan-Induced Inflammation or unilateral sciatic nerve transection. As described previously [Xu, X.-J., Hao, J.-X., Wiesenfeld-Hallin, Z., 1996. Orphanin FQ or antiorphanin FQ: potent spinal antinociceptive effect of orphanin FQ/orphanin FQ in the rat. NeuroReport 7, 2092–2094.], intrathecal orphanin FQ induced a dose-dependent depression of the flexor reflex with a ED50 of 965 ng. Initial reflex facilitation was noted in some experiments at lower doses (10 or 100 ng). A similar bi-phasic response pattern to intrathecal orphanin FQ was observed in experiments conducted in inflamed or axotomized rats. However, the magnitude of the initial reflex facilitation was significantly increased in inflamed rats compared to normals whereas the duration of reflex depression was significantly shortened. The ED50 for reflex depression was 2.4 μg for inflamed rats. In contrast, axotomy did not significantly alter the facilitatory and depressive effect of orphanin FQ with ED50 for reflex depression being 374 ng. These results confirmed an inhibitory action of orphanin FQ on spinal nociception in rats. It is suggested that the effect of orphanin FQ may be modulated by Inflammation and nerve injury. In particular, unlike morphine, there seems to be no reduction in the effect of spinal orphanin FQ in inducing antinociception after peripheral nerve axotomy.

  • effects of intrathecal orphanin fq on a flexor reflex in the rat after Inflammation or peripheral nerve section
    European Journal of Pharmacology, 1999
    Co-Authors: Isabella S Xu, Stefan Grass, Z Wiesenfeldhallin, Xiao-jun Xu
    Abstract:

    We examined the effects of intrathecal orphanin FQ, the endogenous ligand for the orphan opioid-like receptor, on the hamstring nociceptive flexor reflex in decerebrate, spinalized, unanesthetized rats after Carrageenan-Induced Inflammation or unilateral sciatic nerve transection. As described previously [Xu, X.-J., Hao, J.-X., Wiesenfeld-Hallin, Z., 1996. Orphanin FQ or antiorphanin FQ: potent spinal antinociceptive effect of orphanin FQ/orphanin FQ in the rat. NeuroReport 7, 2092–2094.], intrathecal orphanin FQ induced a dose-dependent depression of the flexor reflex with a ED50 of 965 ng. Initial reflex facilitation was noted in some experiments at lower doses (10 or 100 ng). A similar bi-phasic response pattern to intrathecal orphanin FQ was observed in experiments conducted in inflamed or axotomized rats. However, the magnitude of the initial reflex facilitation was significantly increased in inflamed rats compared to normals whereas the duration of reflex depression was significantly shortened. The ED50 for reflex depression was 2.4 μg for inflamed rats. In contrast, axotomy did not significantly alter the facilitatory and depressive effect of orphanin FQ with ED50 for reflex depression being 374 ng. These results confirmed an inhibitory action of orphanin FQ on spinal nociception in rats. It is suggested that the effect of orphanin FQ may be modulated by Inflammation and nerve injury. In particular, unlike morphine, there seems to be no reduction in the effect of spinal orphanin FQ in inducing antinociception after peripheral nerve axotomy.

  • the effect of intrathecal neuropeptide y on the flexor reflex in rats after carrageenan induced Inflammation
    Neuropeptides, 1998
    Co-Authors: Isabella S Xu, Tomas Hokfelt, Rurong Ji, Z Wiesenfeldhallin
    Abstract:

    We examined the effects of intrathecal (i.t.) administration of neuropeptide Y (NPY) on the excitability of the flexor reflex in normal rats and 24 h after Inflammation induced by subcutaneous carrageenan. In normal rats, i.t. NPY at low doses (10 and 100 ng) caused a brief facilitation of the flexor reflex with no subsequent depression. At higher doses (1 and 10 μg), the effect of NPY was mainly inhibitory, causing substantial and usually prolonged depression of the flexor reflex. At 24 h after the injection of carrageenan, when Inflammation was at its peak, the magnitude of the reflex was increased and discharge duration became prolonged. I.t. NPY produced similar pattern of dose-dependent facilitatory and depressive effects on the flexor reflex. The facilitatory effect of i.t. NPY, particularly for the higher doses, was significantly enhanced in inflamed rats compared to normals. In contrast, the depressive effect of high doses of i.t. NPY was unchanged. These data suggest that the changes in levels of NPY and NPY receptors in the spinal cord known to occur after Inflammation, are associated with an increased excitatory effect of this peptide.

Boning Yang - One of the best experts on this subject based on the ideXlab platform.

  • antinociceptive effects of galanin in the rat tuberomammillary nucleus and the plasticity of galanin receptor 1 during hyperalgesia
    Journal of Neuroscience Research, 2004
    Co-Authors: Ji Li, Boning Yang, Longchuan Yu
    Abstract:

    Although the tuberomammillary nucleus (TM) is well defined in terms of anatomy and neurochemistry, little is known about its function in nociceptive modulation. There was an abundance of galanin-immunoreactive fibers in the TM, and galanin has been implicated in pain processing. The present study assessed the role of galanin in the modulation of nociception in the TM of rats. Intra-TM injection of galanin dose-dependently increased the hindpaw withdrawal latency of rats to a noxious thermal stimulus, indicating an antinociceptive role of galanin in the TM. The antinociceptive effect of galanin was blocked by a subsequent intra-TM injection of galantide, a putative galanin receptor antagonist, suggesting that the antinociceptive effect of galanin is mediated by galanin receptors. Moreover, there was abundant galanin receptor 1 (GalR1) in the TM, and the number of GalR1-positive neurons in the ipsilateral TM increased significantly after unilateral loose ligation of the sciatic nerve compared with the contralateral TM or the TM of intact rats. However, the number of GalR1-positive neurons was not significantly altered by Carrageenan-Induced Inflammation, in either the ipsilateral or the contralateral TM. The results suggest that galanin and GalR1 in the TM may play important roles in pain regulation. © 2004 Wiley-Liss, Inc.

  • Antinociceptive effects of galanin in the rat tuberomammillary nucleus and the plasticity of galanin receptor 1 during hyperalgesia.
    Journal of neuroscience research, 2004
    Co-Authors: Yan-gang Sun, Boning Yang
    Abstract:

    Although the tuberomammillary nucleus (TM) is well defined in terms of anatomy and neurochemistry, little is known about its function in nociceptive modulation. There was an abundance of galanin-immunoreactive fibers in the TM, and galanin has been implicated in pain processing. The present study assessed the role of galanin in the modulation of nociception in the TM of rats. Intra-TM injection of galanin dose-dependently increased the hindpaw withdrawal latency of rats to a noxious thermal stimulus, indicating an antinociceptive role of galanin in the TM. The antinociceptive effect of galanin was blocked by a subsequent intra-TM injection of galantide, a putative galanin receptor antagonist, suggesting that the antinociceptive effect of galanin is mediated by galanin receptors. Moreover, there was abundant galanin receptor 1 (GalR1) in the TM, and the number of GalR1-positive neurons in the ipsilateral TM increased significantly after unilateral loose ligation of the sciatic nerve compared with the contralateral TM or the TM of intact rats. However, the number of GalR1-positive neurons was not significantly altered by Carrageenan-Induced Inflammation, in either the ipsilateral or the contralateral TM. The results suggest that galanin and GalR1 in the TM may play important roles in pain regulation.

Z Wiesenfeldhallin - One of the best experts on this subject based on the ideXlab platform.

  • effects of intrathecal orphanin fq on a flexor reflex in the rat after Inflammation or peripheral nerve section
    European Journal of Pharmacology, 1999
    Co-Authors: Isabella S Xu, Stefan Grass, Z Wiesenfeldhallin, Xiao-jun Xu
    Abstract:

    We examined the effects of intrathecal orphanin FQ, the endogenous ligand for the orphan opioid-like receptor, on the hamstring nociceptive flexor reflex in decerebrate, spinalized, unanesthetized rats after Carrageenan-Induced Inflammation or unilateral sciatic nerve transection. As described previously [Xu, X.-J., Hao, J.-X., Wiesenfeld-Hallin, Z., 1996. Orphanin FQ or antiorphanin FQ: potent spinal antinociceptive effect of orphanin FQ/orphanin FQ in the rat. NeuroReport 7, 2092–2094.], intrathecal orphanin FQ induced a dose-dependent depression of the flexor reflex with a ED50 of 965 ng. Initial reflex facilitation was noted in some experiments at lower doses (10 or 100 ng). A similar bi-phasic response pattern to intrathecal orphanin FQ was observed in experiments conducted in inflamed or axotomized rats. However, the magnitude of the initial reflex facilitation was significantly increased in inflamed rats compared to normals whereas the duration of reflex depression was significantly shortened. The ED50 for reflex depression was 2.4 μg for inflamed rats. In contrast, axotomy did not significantly alter the facilitatory and depressive effect of orphanin FQ with ED50 for reflex depression being 374 ng. These results confirmed an inhibitory action of orphanin FQ on spinal nociception in rats. It is suggested that the effect of orphanin FQ may be modulated by Inflammation and nerve injury. In particular, unlike morphine, there seems to be no reduction in the effect of spinal orphanin FQ in inducing antinociception after peripheral nerve axotomy.

  • the effect of intrathecal neuropeptide y on the flexor reflex in rats after carrageenan induced Inflammation
    Neuropeptides, 1998
    Co-Authors: Isabella S Xu, Tomas Hokfelt, Rurong Ji, Z Wiesenfeldhallin
    Abstract:

    We examined the effects of intrathecal (i.t.) administration of neuropeptide Y (NPY) on the excitability of the flexor reflex in normal rats and 24 h after Inflammation induced by subcutaneous carrageenan. In normal rats, i.t. NPY at low doses (10 and 100 ng) caused a brief facilitation of the flexor reflex with no subsequent depression. At higher doses (1 and 10 μg), the effect of NPY was mainly inhibitory, causing substantial and usually prolonged depression of the flexor reflex. At 24 h after the injection of carrageenan, when Inflammation was at its peak, the magnitude of the reflex was increased and discharge duration became prolonged. I.t. NPY produced similar pattern of dose-dependent facilitatory and depressive effects on the flexor reflex. The facilitatory effect of i.t. NPY, particularly for the higher doses, was significantly enhanced in inflamed rats compared to normals. In contrast, the depressive effect of high doses of i.t. NPY was unchanged. These data suggest that the changes in levels of NPY and NPY receptors in the spinal cord known to occur after Inflammation, are associated with an increased excitatory effect of this peptide.

Zsuzsanna Wiesenfeldhallin - One of the best experts on this subject based on the ideXlab platform.

  • effects of intrathecal orphanin fq on a flexor reflex in the rat after Inflammation or peripheral nerve section
    European Journal of Pharmacology, 1999
    Co-Authors: Isabella S Xu, Stefan Grass, Zsuzsanna Wiesenfeldhallin, Xiao-jun Xu
    Abstract:

    We examined the effects of intrathecal orphanin FQ, the endogenous ligand for the orphan opioid-like receptor, on the hamstring nociceptive flexor reflex in decerebrate, spinalized, unanesthetized rats after Carrageenan-Induced Inflammation or unilateral sciatic nerve transection. As described previously [Xu, X.-J., Hao, J.-X., Wiesenfeld-Hallin, Z., 1996. Orphanin FQ or antiorphanin FQ: potent spinal antinociceptive effect of orphanin FQ/orphanin FQ in the rat. NeuroReport 7, 2092–2094.], intrathecal orphanin FQ induced a dose-dependent depression of the flexor reflex with a ED50 of 965 ng. Initial reflex facilitation was noted in some experiments at lower doses (10 or 100 ng). A similar bi-phasic response pattern to intrathecal orphanin FQ was observed in experiments conducted in inflamed or axotomized rats. However, the magnitude of the initial reflex facilitation was significantly increased in inflamed rats compared to normals whereas the duration of reflex depression was significantly shortened. The ED50 for reflex depression was 2.4 μg for inflamed rats. In contrast, axotomy did not significantly alter the facilitatory and depressive effect of orphanin FQ with ED50 for reflex depression being 374 ng. These results confirmed an inhibitory action of orphanin FQ on spinal nociception in rats. It is suggested that the effect of orphanin FQ may be modulated by Inflammation and nerve injury. In particular, unlike morphine, there seems to be no reduction in the effect of spinal orphanin FQ in inducing antinociception after peripheral nerve axotomy.

  • anti hyperalgesic and anti allodynic effects of intrathecal nociceptin orphanin fq in rats after spinal cord injury peripheral nerve injury and Inflammation
    Pain, 1998
    Co-Authors: Jingxia Hao, Zsuzsanna Wiesenfeldhallin
    Abstract:

    Abstract We examined the effects of intrathecal nociceptin, the endogenous ligand for the orphan opioid receptor-like receptor, on abnormal pain-related behaviors in rats after Carrageenan-Induced Inflammation and photochemically-induced peripheral nerve or spinal cord ischemic injury. Intrathecal nociceptin dose-dependently alleviated mechanical and cold allodynia-like behavior in the two models of neuropathic pain. The heat hyperalgesia associated with peripheral Inflammation was also significantly reduced, although the efficacy of the anti-hyperalgesic effect of nociceptin in the Inflammation model was decreased. Intrathecal nociceptin also induced significant antinociceptin on the tail-flick test in all three groups of rats. However, the antinociceptive effect of nociceptin was significantly reduced in rats with peripheral nerve injury. These results indicated that spinally administered nociceptin has anti-allodynic and anti-hyperalgesic effects in animal models of tonic or chronic pain of different origins. Peripheral Inflammation and nerve injury may induce spinal plasticity which leads to altered potency and efficacy of nociceptin.