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1.
Peptides ; 27(4): 760-8, 2006 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-16226344

RESUMO

The antinociceptive mechanisms of the selective mu-opioid receptor agonists [D-Ala2,NMePhe4,Gly(ol)5]enkephalin (DAMGO), H-Tyr-D-Arg-Phe-beta-Ala-OH (TAPA) or H-Tyr-D-Arg-Phe-beta-Ala-NH2 (TAPA-NH2) against substance P (SP)- or capsaicin-elicited nociceptive behaviors was investigated in mice. DAMGO, TAPA or TAPA-NH2 given intrathecally inhibited the nociceptive behaviors elicited by intrathecally administered SP or capsaicin, and these antinociceptive effects were completely eliminated by intrathecal co-administration with D-Phe-Cys-Tyr-D-Trp-Orn-Thr-Pen-Thr-NH2 (CTOP), a selective mu-opioid receptor antagonist. Pretreatment subcutaneously with naloxonazine, a selective mu1-opioid receptor antagonist, partially attenuated the antinociceptive effect of TAPA-NH2, but not DAMGO and TAPA, against SP. However, the antinociception induced by TAPA, but not DAMGO and TAPA-NH2, against capsaicin was significantly inhibited by naloxonazine. On the other hand, co-administration intrathecally with Tyr-D-Pro-Trp-Gly-NH2 (D-Pro2-Tyr-W-MIF-1), a selective mu2-opioid receptor antagonist, significantly attenuated the antinociceptive effects of DAMGO, but not TAPA and TAPA-NH2, against capsaicin, while the antinociceptions induced by three opioid peptides against SP were significantly inhibited by D-Pro2-Tyr-W-MIF-1. These results suggest that differential inhibitory mechanisms on pre- and postsynaptic sites in the spinal cord contribute to the antinociceptive effects of the three mu-opioid peptides.


Assuntos
Capsaicina/antagonistas & inibidores , Capsaicina/farmacologia , Entorpecentes/farmacologia , Dor/tratamento farmacológico , Receptores Opioides mu/metabolismo , Substância P/antagonistas & inibidores , Substância P/farmacologia , Analgésicos Opioides/farmacologia , Animais , Masculino , Camundongos , Dor/fisiopatologia , Medição da Dor
2.
Eur J Pharmacol ; 540(1-3): 67-72, 2006 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-16730704

RESUMO

The involvement of spinal mu-opioid receptor subtypes on the antinociception induced by i.t.-administered Tyr-D-Arg-Phe-sarcosine (TAPS), a N-terminal tetrapeptide analog of dermorphin, was determined in mice tail-flick test. Intrathecal administration of TAPS produced the marked inhibition of the tail-flick response in a dose-dependent manner. The antinociception induced by TAPS was completely eliminated by i.t.-co-administration of Tyr-D-Pro-Phe-Phe-NH2 (D-Pro2-endomorphin-2), the mu1-opioid receptor antagonist, whereas i.t. co-treatment with Tyr-D-Pro-Trp-Phe-NH2 (D-Pro2-endomorphin-1) or Tyr-D-Pro-Trp-Gly-NH2 (D-Pro2-Tyr-W-MIF-1), the mu2-opioid receptor antagonists, did not affect the TAPS-induced antinociception. In contrast, the antinociception induced by i.t.-administered [D-Ala2,N-MePhe4,Gly-ol5]enkephalin was significantly attenuated by i.t.-co-administration of D-Pro2-endomorphin-1 or D-Pro2-Tyr-W-MIF-1, but not D-Pro2-endomorphin-2. These results suggest that TAPS may stimulate spinal mu1-opioid receptors to produce the antinociception.


Assuntos
Hiperalgesia/prevenção & controle , Oligopeptídeos/farmacologia , Receptores Opioides mu/metabolismo , Analgésicos/administração & dosagem , Analgésicos/farmacologia , Analgésicos Opioides/administração & dosagem , Analgésicos Opioides/farmacologia , Animais , Relação Dose-Resposta a Droga , Ala(2)-MePhe(4)-Gly(5)-Encefalina/administração & dosagem , Ala(2)-MePhe(4)-Gly(5)-Encefalina/farmacologia , Temperatura Alta/efeitos adversos , Hiperalgesia/etiologia , Hiperalgesia/metabolismo , Injeções Espinhais , Hormônio Inibidor da Liberação de MSH/administração & dosagem , Hormônio Inibidor da Liberação de MSH/análogos & derivados , Hormônio Inibidor da Liberação de MSH/farmacologia , Masculino , Camundongos , Oligopeptídeos/administração & dosagem , Medição da Dor/métodos , Isoformas de Proteínas/agonistas , Isoformas de Proteínas/antagonistas & inibidores , Isoformas de Proteínas/metabolismo , Receptores Opioides mu/agonistas , Receptores Opioides mu/antagonistas & inibidores , Medula Espinal/metabolismo
3.
Nihon Hoshasen Gijutsu Gakkai Zasshi ; 61(9): 1341-8, 2005 Sep 20.
Artigo em Japonês | MEDLINE | ID: mdl-16192925

RESUMO

Three-dimensional imaging with MRI is a useful method for neurosurgical simulations. As in our previous study, we have constructed three-dimensional surface anatomical scanning (3D-SAS) from the data of contrast enhanced 3D fast spoiled gradient recalled acquisition in the steady state (3D-FSPGR) sequence. Using this technique, it is possible to generate 3D images from the data of only one acquisition, without using the fusion function. In our previous study, we did not compare the 3D images with the operative views at surgery. In the present study, two radiologists and one neurosurgeon assessed the 3D images in comparison with the operative views. There were problems in some cases, including unclear cortical sulci owing to brain swelling, lack of depiction of the cortical veins owing to meningeal enhancement, inadequate distinction between pial veins and meningeal veins, and so forth. However, in the majority of cases, 3D-SAS with 3D-FSPGR was able to demonstrate good anatomical conformity with the operative views, indicating the clinical usefulness of this technique.


Assuntos
Neoplasias Encefálicas/diagnóstico , Imageamento por Ressonância Magnética/normas , Adolescente , Adulto , Idoso , Neoplasias Encefálicas/patologia , Feminino , Humanos , Imageamento Tridimensional , Masculino , Pessoa de Meia-Idade
4.
Nihon Hoshasen Gijutsu Gakkai Zasshi ; 58(12): 1632-8, 2002 Dec.
Artigo em Japonês | MEDLINE | ID: mdl-12577023

RESUMO

The purpose of this study was to determine the usefulness of three-dimensional (3D) MR imaging of brain tumors for surgical planning. Sixty-nine patients with various tumors of the brain were included in the present study. Using a volume-rendering (VR) method on an independent workstation, 3D-MR images were obtained with the fast-SPGR sequence after Gd-DTPA administration. VR images could show an exact relationship between the surface of the brain and major vessels. However, in patients with deeply located tumors, VR images did not necessarily provide sufficient information as to the relationship between the tumor and vessels. In combination with a surface-rendering method, 3D-MR imaging could demonstrate the exact relationships among the tumors, major vessels, and surface of the brain. In tumors without contrast enhancement, this method was able to show 3D images of tumors with surrounding structures. For neurosurgeons, 3D-MR images were useful for understanding the surface anatomy and surrounding structures of the tumors prior to surgery. These images were also helpful in explaining the condition of the disease to patients and their families.


Assuntos
Neoplasias Encefálicas/cirurgia , Simulação por Computador , Processamento de Imagem Assistida por Computador , Imageamento Tridimensional , Imageamento por Ressonância Magnética/métodos , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Criança , Pré-Escolar , Imagem de Difusão por Ressonância Magnética , Feminino , Humanos , Masculino , Pessoa de Meia-Idade
5.
J Pharmacol Exp Ther ; 317(1): 362-8, 2006 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-16394196

RESUMO

The antinociception induced by i.t. or i.c.v. administration of endomorphins is mediated via mu-opioid receptors. However, although endomorphins do not have an appreciable affinity for kappa-opioid receptors, pretreatment with the kappa-opioid receptor antagonist norbinaltorphimine markedly reduces the antinociceptive response to i.c.v. or i.t. administered endomorphin-2 but not endomorphin-1. These results suggest that endomorphin-2 initially stimulates mu-opioid receptors, which subsequently induce the release of dynorphins that act on kappa-opioid receptors to produce antinociception. The present study was performed in mice to determine whether the release of dynorphins by i.t. administered endomorphin-2 is mediated through mu-opioid receptors to produce antinociception. Intrathecal pretreatment with an antiserum against dynorphin A-(1-17), but not against dynorphin B-(1-13) or alpha-neoendorphin, dose-dependently prevented the paw-withdrawal inhibition by endomorphin-2. The pretreatments with these antisera did not affect the endomorphin-1- or [D-Ala(2),MePhe(4),Gly(ol)(5)]enkephalin-induced paw-withdrawal inhibition. The attenuation of endomorphin-2-induced antinociception by i.t. pretreatment with an antiserum against dynorphin A-(1-17) or s.c. pretreatment with norbinaltorphimine was blocked dose-dependently by s.c. pretreatment with the mu-opioid receptor antagonist beta-funaltrexamine or the mu(1)-opioid receptor antagonist naloxonazine at ultra-low doses that are ineffective against mu-opioid receptor agonists. These results suggest that the spinal antinociception induced by endomorphin-2 is mediated through the stimulation of a distinct subtype of mu(1)-opioid receptor that induces the release of the endogenous kappa-opioid peptide dynorphin A-(1-17) in the spinal cord.


Assuntos
Analgésicos Opioides/farmacologia , Dinorfinas/metabolismo , Oligopeptídeos/farmacologia , Dor/tratamento farmacológico , Receptores Opioides mu/agonistas , Analgésicos Opioides/administração & dosagem , Analgésicos Opioides/uso terapêutico , Animais , Relação Dose-Resposta a Droga , Dinorfinas/imunologia , Temperatura Alta/efeitos adversos , Soros Imunes/farmacologia , Injeções Espinhais , Masculino , Camundongos , Camundongos Endogâmicos , Oligopeptídeos/administração & dosagem , Oligopeptídeos/uso terapêutico , Dor/metabolismo , Medição da Dor , Estimulação Física , Fatores de Tempo
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