α2A subtype of presynaptic α2-Adrenoceptors modulates the release of [3H]-noradrenaline from rat spinal cord

Umeda, Eiichiro; Satoh, Tetsuo; Nagashima, Hideo; Potter, Pamela E.; Tarkovács, Gabor; Vizi, E.S.

doi:10.1016/s0361-9230(96)00223-7

Cited by 39 publications

(11 citation statements)

References 21 publications

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“…In addition, NBAT labeling in forebrain axons that have adrenergic-like distributions also may reflect their capacity for transport of L-arginine and/or the decarboxylated product, agmatine . Agmatine binds to ␣ 2 -adrenergic receptors, which are known to be located mainly at presynaptic sites on noradrenergic terminals (Kiss et al, 1995;Umeda et al, 1997). In animals pretreated with colchicine to block axonal transport, there is a marked enhancement of somatic labeling for agmatine in brainstem autonomic nuclei and in many cortical and subcortical limbic structures in a distribution similar to that of NBAT in the present study (Otake et al, 1998).…”

Section: Nbat-immunogold Particles Are Associated With Plasma Membranessupporting

confidence: 60%

Regional and subcellular distribution of a neutral and basic amino acid transporter in forebrain neurons containing nitric oxide synthase

et al. 1999

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Section: Nbat-immunogold Particles Are Associated With Plasma Membranessupporting

confidence: 60%

Regional and subcellular distribution of a neutral and basic amino acid transporter in forebrain neurons containing nitric oxide synthase

et al. 1999

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“…Treatment with prazosin and yohimbine significantly antagonized the antinociceptive action caused by AMB, and this effect may be mediated by the activation of the adrenergic system. Umeda and co-workers 16) demonstrate that nonsynaptic release of norepinephrine from rat spinal cord slices is modulated via presynaptic a 2A -adrenergic auto receptors. It was observed that the a 2A -adrenoreceptor agonist clonidine inhibited this pathway, whereas yohimbine (a non subtype selective a 2A antagonist) enhanced the release of norepinephrine in response to neuronal stimulation.…”

Section: Discussionmentioning

confidence: 97%

Assessment of Mechanisms Involved in Antinociception Caused by Myrsinoic Acid B

Hess

Padoani

Scorteganha

et al. 2010

Biological & Pharmaceutical Bulletin

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Considerable efforts have recently been made to discover new analgesic and antiinflammatory agents with increased efficacy and improved side effect profiles. In this context, the compounds obtained from medicinal plants have been extensively studied.1,2) Prenylated aromatic compounds isolated from plant sources are common in the literature, including some that are diprenylated benzoic acids. This class of compounds is present in Rapanea genus and has been demonstrated to have anti-inflammatory activity, 3) then the compound 5-carboxy-2,3-dihydro-2-(1Ј,5Ј-dimethyl-1Ј-hydroxy-4Ј-hexenyl)-7-(3Љ-methyl-2Љ-butenyl) benzofuran, also known as myrsinoic acid B (AMB) (Fig. 1) was chosen in this study. It was first isolated as methyl ester from Rapanea umbellatta 4) and was also reported in R. lancifolia, R. guaianensis, 5) R. Myricoides 6) and R. Seguinii.3) So far only antiinflammatory and methioninase inhibitory activities have been reported for this compound.3,7) We have previously verified that AMB, isolated from the bark of CHCl 3 extract of Rapanea ferruginea, exhibits significant and potent antinociceptive action when evaluated in some pharmacological models of pain in mice. 8) In this study, we investigated some of the possible mechanisms, underlying the antinociceptive action of AMB. Extraction and Isolation of AMB Bark of Rapanea ferruginea (600 g) was dried at 40°C for 2 d, powdered and successively extracted by maceration with CHCl 3 for 7 d at room temperature. The extract was concentrated under reduced pressure, to yield residues (70.2 g). The CHCl 3 extract (60 g) was chromatographed in a silica-gel column with hexane/ ethyl acetate. The fraction eluted with 40% ethyl-acetate in hexane to give impure AMB. This fraction (8.5 g) was rechromatographed in a silica-gel column and with 30% ethyl-acetate in hexane give pure AMB (4.3 g). MATERIALS AND METHODS Plant Material

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“…Our results showed that atropine, given systemically, reverted the analgesic effect caused by NI only in the second phase of the dolorous process, thus suggesting that the antinociception depended on the cholinergic system. Umeda et al (1997) demonstrated that nonsynaptic release of noradrenaline from rat spinal cord slices is modulated via presynaptic a 2 -adrenergic auto receptors. It was observed that the a 2 -adrenoreceptor antagonist clonidine inhibited this pathway, whereas yohimbine (a non subtype Discussion selective a 2 antagonist) enhanced the release of noradrenaline in response to neuronal stimulation (Vizi et al 1986).…”

Section: Discussionmentioning

confidence: 98%

Analysis of the mechanism of antinociceptive action of niga-ichigoside F1 obtained from Rubus imperialis (Rosaceae)

Ardenghi

Kanegusuku

Niero

et al. 2006

Journal of Pharmacy and Pharmacology

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We have previously verified that niga-ichigoside F(1) (NI), a triterpene isolated from Rubus imperialis, exhibits significant and potent antinociceptive action when evaluated in some pharmacological models of pain in mice. This effect was confirmed in other experimental models and also the mechanism of action has been evaluated. The antinociception caused by NI (60 mg kg(-1)) in both phases of the formalin test was significantly attenuated by intraperitoneal injection of mice with haloperidol (a dopaminergic antagonist, 0.20 mg kg(-1)) and L-arginine (precursor of nitric oxide, 600 mg kg(-1)). Regarding the cholinergic system, atropine (a cholinergic antagonist 60 mg kg(-1)) reverted only the second phase. The effect of NI was not affected by treatment of mice with yohimbine (an alpha2-adrenoceptor antagonist, 0.15 mg kg(-1)). The same pharmacological profile was observed for the administration of naloxone (an opioid receptor antagonist, 1 mg kg(-1)). On the other hand, intraperitoneal injection caused dose-related and significant effects against glutamate- and capsaicin-induced pain, respectively. In conclusion, the marked antinociception of NI appears to be related to the dopaminergic, cholinergic, glutamatergic, tachykininergic and oxinitrergic systems, supporting the ethnomedical use of Rubus imperialis (Rosaceae).

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α2A subtype of presynaptic α2-Adrenoceptors modulates the release of [3H]-noradrenaline from rat spinal cord

Cited by 39 publications

References 21 publications

Regional and subcellular distribution of a neutral and basic amino acid transporter in forebrain neurons containing nitric oxide synthase

Regional and subcellular distribution of a neutral and basic amino acid transporter in forebrain neurons containing nitric oxide synthase

Assessment of Mechanisms Involved in Antinociception Caused by Myrsinoic Acid B

Analysis of the mechanism of antinociceptive action of niga-ichigoside F1 obtained from Rubus imperialis (Rosaceae)

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