The Experts below are selected from a list of 66 Experts worldwide ranked by ideXlab platform
Shinichi Nakamura - One of the best experts on this subject based on the ideXlab platform.
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DOPA Itself Facilitates Noradrenaline Release via Presynaptic β-adrenoceptors in Rat Hypothalamic Slices — DOPA is Probably a Neuroactive Substance
Presynaptic Receptors and Neuronal Transporters, 2013Co-Authors: Y Misu, Y Goshima, Shinichi NakamuraAbstract:ABSTRACT We summarized briefly our data concerning the release of endogenous DOPA and the pharmacological actions of exogenously applied L-DOPA in rat striatal and hypothalamic slices. The lowest nanomolar concentrations of L-DOPA facilitate the release of noradrenaline (NA) and dopamine via propranolol-sensitive presynaptic β-adrenoceptors under essentially complete inhibition of L-aromatic amino acid decarboxylase. In rat hypothalamic slices, L-DOPA methyl ester antagonizes competitively this L-DOPA-indueed facilitation of the NA release, whereas 1-propranolol antagonizes non-competitively. DOPA is probably a Neuroactive Substance and “a recognition site” of DOPA differs from presynaptic β-adrenoceptors.
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review on the relationship between nicotinic acetylcholine receptors and dopaminergic neurotransmission in the central nervous system dopa is an endogenous Neuroactive Substance
Yakubutsu seishin kodo = Japanese journal of psychopharmacology, 1993Co-Authors: Yoshimi Misu, Shinichi Nakamura, Yoshio Goshima, T Miyamae, T KuboAbstract:: L-3,4-Dihydroxyphenylalanine (DOPA) is believed to be an inert precursor for dopamine (DA). Contrary, transmitter-like endogenous DOPA is released from in vitro and in vivo striata: DOPA is released by neuronal activities under physiological conditions from striata of conscious rats. Furthermore, exogenous nanomolar DOPA itself produces an in vitro presynaptic response to facilitate the catecholamine release. An in vivo postsynaptic depressor response is elicited by DOPA microinjected into the nucleus tractus solitarii. These responses are antagonized by L-DOPA methyl ester, a competitive DOPA antagonist. In striata, DOPA is an endogenous potentiator for presynaptic beta-adrenoceptors to facilitate the DA release and also probably for postsynaptic D2-receptors to increase locomotor activities. Nicotine releases DA and transmitter-like DOPA in vitro and in vivo striata. Nicotine (0.1-1.0 mg/kg, sc) dose-dependently increases locomotor activities. This increase is stereoselective and mecamylamine (1.0 mg/kg, sc)-sensitive but not antagonized by L-DOPA methyl ester (200 micrograms, ivt). Then, a selective low ip dose of alpha-methyl-p-tyrosine (alpha-MPT) to inhibit the basal release of DOPA without decreasing the basal release of DA was explored in vivo striata: it was 3 mg/kg. Pretreatment with this dose did inhibit the nicotine-induced increases in locomotor activities. This result suggests that endogenously released DOPA is in part relevant to nicotine-induced behavior in rats.
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dopa itself facilitates noradrenaline release via presynaptic β adrenoceptors in rat hypothalamic slices dopa is probably a Neuroactive Substance
Presynaptic Receptors and Neuronal Transporters#R##N#Official Satellite Symposium to the IUPHAR 1990 Congress Held in Rouen France on 26–29 June 1990, 1991Co-Authors: Y Misu, Y Goshima, Shinichi NakamuraAbstract:ABSTRACT We summarized briefly our data concerning the release of endogenous DOPA and the pharmacological actions of exogenously applied L-DOPA in rat striatal and hypothalamic slices. The lowest nanomolar concentrations of L-DOPA facilitate the release of noradrenaline (NA) and dopamine via propranolol-sensitive presynaptic β-adrenoceptors under essentially complete inhibition of L-aromatic amino acid decarboxylase. In rat hypothalamic slices, L-DOPA methyl ester antagonizes competitively this L-DOPA-indueed facilitation of the NA release, whereas 1-propranolol antagonizes non-competitively. DOPA is probably a Neuroactive Substance and “a recognition site” of DOPA differs from presynaptic β-adrenoceptors.
Y Misu - One of the best experts on this subject based on the ideXlab platform.
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DOPA Itself Facilitates Noradrenaline Release via Presynaptic β-adrenoceptors in Rat Hypothalamic Slices — DOPA is Probably a Neuroactive Substance
Presynaptic Receptors and Neuronal Transporters, 2013Co-Authors: Y Misu, Y Goshima, Shinichi NakamuraAbstract:ABSTRACT We summarized briefly our data concerning the release of endogenous DOPA and the pharmacological actions of exogenously applied L-DOPA in rat striatal and hypothalamic slices. The lowest nanomolar concentrations of L-DOPA facilitate the release of noradrenaline (NA) and dopamine via propranolol-sensitive presynaptic β-adrenoceptors under essentially complete inhibition of L-aromatic amino acid decarboxylase. In rat hypothalamic slices, L-DOPA methyl ester antagonizes competitively this L-DOPA-indueed facilitation of the NA release, whereas 1-propranolol antagonizes non-competitively. DOPA is probably a Neuroactive Substance and “a recognition site” of DOPA differs from presynaptic β-adrenoceptors.
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dopa itself facilitates noradrenaline release via presynaptic β adrenoceptors in rat hypothalamic slices dopa is probably a Neuroactive Substance
Presynaptic Receptors and Neuronal Transporters#R##N#Official Satellite Symposium to the IUPHAR 1990 Congress Held in Rouen France on 26–29 June 1990, 1991Co-Authors: Y Misu, Y Goshima, Shinichi NakamuraAbstract:ABSTRACT We summarized briefly our data concerning the release of endogenous DOPA and the pharmacological actions of exogenously applied L-DOPA in rat striatal and hypothalamic slices. The lowest nanomolar concentrations of L-DOPA facilitate the release of noradrenaline (NA) and dopamine via propranolol-sensitive presynaptic β-adrenoceptors under essentially complete inhibition of L-aromatic amino acid decarboxylase. In rat hypothalamic slices, L-DOPA methyl ester antagonizes competitively this L-DOPA-indueed facilitation of the NA release, whereas 1-propranolol antagonizes non-competitively. DOPA is probably a Neuroactive Substance and “a recognition site” of DOPA differs from presynaptic β-adrenoceptors.
Y Goshima - One of the best experts on this subject based on the ideXlab platform.
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DOPA Itself Facilitates Noradrenaline Release via Presynaptic β-adrenoceptors in Rat Hypothalamic Slices — DOPA is Probably a Neuroactive Substance
Presynaptic Receptors and Neuronal Transporters, 2013Co-Authors: Y Misu, Y Goshima, Shinichi NakamuraAbstract:ABSTRACT We summarized briefly our data concerning the release of endogenous DOPA and the pharmacological actions of exogenously applied L-DOPA in rat striatal and hypothalamic slices. The lowest nanomolar concentrations of L-DOPA facilitate the release of noradrenaline (NA) and dopamine via propranolol-sensitive presynaptic β-adrenoceptors under essentially complete inhibition of L-aromatic amino acid decarboxylase. In rat hypothalamic slices, L-DOPA methyl ester antagonizes competitively this L-DOPA-indueed facilitation of the NA release, whereas 1-propranolol antagonizes non-competitively. DOPA is probably a Neuroactive Substance and “a recognition site” of DOPA differs from presynaptic β-adrenoceptors.
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dopa itself facilitates noradrenaline release via presynaptic β adrenoceptors in rat hypothalamic slices dopa is probably a Neuroactive Substance
Presynaptic Receptors and Neuronal Transporters#R##N#Official Satellite Symposium to the IUPHAR 1990 Congress Held in Rouen France on 26–29 June 1990, 1991Co-Authors: Y Misu, Y Goshima, Shinichi NakamuraAbstract:ABSTRACT We summarized briefly our data concerning the release of endogenous DOPA and the pharmacological actions of exogenously applied L-DOPA in rat striatal and hypothalamic slices. The lowest nanomolar concentrations of L-DOPA facilitate the release of noradrenaline (NA) and dopamine via propranolol-sensitive presynaptic β-adrenoceptors under essentially complete inhibition of L-aromatic amino acid decarboxylase. In rat hypothalamic slices, L-DOPA methyl ester antagonizes competitively this L-DOPA-indueed facilitation of the NA release, whereas 1-propranolol antagonizes non-competitively. DOPA is probably a Neuroactive Substance and “a recognition site” of DOPA differs from presynaptic β-adrenoceptors.
H. Takagi - One of the best experts on this subject based on the ideXlab platform.
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Calcitonin gene-related peptide- and Substance P-immunoreactive axons in the nucleus gracilis of the rat with special reference to axonal dystrophy: light and electron microscopic observations
Acta Neuropathologica, 1995Co-Authors: K. Fujiwara, S. Y. Baek, T. Arakawa, K. Kobayashi, H. TakagiAbstract:Calcitonin gene-related peptide (CGRP) and Substance P (SP)-immunoreactive (IR) axons in the nucleus gracilis of normal rats (1–15 months of age) were studied by light and electron microscopy. Besides many CGRP-IR and SP-IR varicosities with normal appearance, we found a few swollen (nearly round or oval) varicosities with either CGRP or SP immunoreactivity. Swollen CGRP-IR varicosities were more frequently seen than SP-IR ones, appearing from 3 months of age and increasing in number and size (up to approximately 25 μm in diameter) with advancing age. At the electron microscopic (EM) level, CGRP-IR and SP-IR swollen varicosities showed dystrophic changes, i.e., many membranous dense bodies, and proliferation of microtubules and neurofilaments. CGRP-IR or SP-IR dystrophic axons also contained many mitochondria and sometimes made synaptic contacts with nonreactive dendrites (occasionally with non-IR axons). These findings suggest that the dystrophic CGRP and SP axonal profiles represent a functionally distinct subpopulation of axonal dystrophy in the nucleus gracilis and use CGRP or SP as a Neuroactive Substance. Using a double-immunostaining method, many of normal CGRP-IR axons were identified to be SP-IR. However, no single dystrophic varicosity was found to contain both CGRP and SP immunoreactivities. These findings suggest that CGRP and SP afferents are independently affected and progress to dystrophic changes.
K. Fujiwara - One of the best experts on this subject based on the ideXlab platform.
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Calcitonin gene-related peptide- and Substance P-immunoreactive axons in the nucleus gracilis of the rat with special reference to axonal dystrophy: light and electron microscopic observations
Acta Neuropathologica, 1995Co-Authors: K. Fujiwara, S. Y. Baek, T. Arakawa, K. Kobayashi, H. TakagiAbstract:Calcitonin gene-related peptide (CGRP) and Substance P (SP)-immunoreactive (IR) axons in the nucleus gracilis of normal rats (1–15 months of age) were studied by light and electron microscopy. Besides many CGRP-IR and SP-IR varicosities with normal appearance, we found a few swollen (nearly round or oval) varicosities with either CGRP or SP immunoreactivity. Swollen CGRP-IR varicosities were more frequently seen than SP-IR ones, appearing from 3 months of age and increasing in number and size (up to approximately 25 μm in diameter) with advancing age. At the electron microscopic (EM) level, CGRP-IR and SP-IR swollen varicosities showed dystrophic changes, i.e., many membranous dense bodies, and proliferation of microtubules and neurofilaments. CGRP-IR or SP-IR dystrophic axons also contained many mitochondria and sometimes made synaptic contacts with nonreactive dendrites (occasionally with non-IR axons). These findings suggest that the dystrophic CGRP and SP axonal profiles represent a functionally distinct subpopulation of axonal dystrophy in the nucleus gracilis and use CGRP or SP as a Neuroactive Substance. Using a double-immunostaining method, many of normal CGRP-IR axons were identified to be SP-IR. However, no single dystrophic varicosity was found to contain both CGRP and SP immunoreactivities. These findings suggest that CGRP and SP afferents are independently affected and progress to dystrophic changes.