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Motor learning in common marmosets: Vestibulo-ocular reflex adaptation and its sensitivity to inhibitors of Purkinje cell long-term depression. Neurosci Res 2014; 83:33-42. [DOI: 10.1016/j.neures.2014.04.002] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2014] [Revised: 04/05/2014] [Accepted: 04/08/2014] [Indexed: 11/21/2022]
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Li X, Ma X, Li W, Tao X, Meng Q, Fan W, Zhang Z. Catalytic Asymmetric Hydrogenation of Ethyl 2-(Benzo[b]thiophen-5-yl)-2-oxoacetate with Ru-SunPhos in the Formal Synthesis of T-588. CHINESE J CHEM 2011. [DOI: 10.1002/cjoc.201100305] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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Mori Y, Shiotani A, Saito K, Araki K, Ikeda K, Nakagawa M, Watabe K, Ogawa K. A Novel Drug Therapy for Recurrent Laryngeal Nerve Injury Using T-588. Laryngoscope 2007; 117:1313-8. [PMID: 17507828 DOI: 10.1097/mlg.0b013e31805f681f] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
OBJECTIVES/HYPOTHESIS We have previously shown that gene therapy using Insulin-like growth factor (IGF)-I, glial cell line-derived neurotrophic factor (GDNF), and brain-derived neurotrophic factor (BDNF), or a combination of these trophic factors, is a treatment option for recurrent laryngeal nerve (RLN) palsy. However, there remain some difficulties preventing this option from becoming a common clinical therapy for RLN injury. Thus, we need to develop novel treatment option that overcomes the problems of gene therapy.R(-)-1-(benzothiophen-5-yl)-2-[2-N,N-diethylamino]ethoxy]ethanol hydrochloride (T-588), a synthetic compound, is known to have neuroprotective effects on neural cells. In the present study, the possibility of new drug treatments using T-588 for RLN injury was assessed using rat models. STUDY DESIGN Animal study. METHODS Animals were administered T-588 for 4 weeks. The neuroprotective effects of T-588 administration after vagal nerve avulsion and neurofunctional recovery after recurrent laryngeal nerve crush were studied using motoneuron cell counting, evaluation of choline acetyltransferase immunoreactivity, the electrophysiologic examination, and the re-mobilization of the vocal fold. RESULTS T-588 administration successfully prevented motoneuron loss and ameliorated the choline acetyltransferase immunoreactivity in the ipsilateral nucleus ambiguus after vagal nerve avulsion. Significant improvements of motor nerve conduction velocity of the RLN and vocal fold movement were observed in the treatment group when compared to controls. CONCLUSION These results indicate that oral administration of T-588 might be a promising therapeutic option in treating peripheral nerve injury.
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Affiliation(s)
- Yuko Mori
- Department of Otolaryngology-Head and Neck Surgery, Keio University School of Medicine, Shinjuku, Tokyo, Japan
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Hirouchi M. [Current status and perspectives on the development of therapeutic agents for Alzheimer's disease]. Nihon Yakurigaku Zasshi 2004; 123:421-7. [PMID: 15170082 DOI: 10.1254/fpj.123.421] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/29/2023]
Abstract
Acetylcholinesterase inhibitors have beneficial effects to improve the cognitive impairment in patients with mild to moderate Alzheimer's disease (AD). In addition, a channel blocker of N-methyl-D-aspartate receptor, memantine hydrochloride, was approved as a therapeutic agent for patients with moderate to severe AD in both EU countries in 2002 and USA in 2003, while the clinical development is still ongoing in Japan. In contrast, the pharmacotherapy for a prime cure against AD is not available in the market, although there has been a worldwide search for novel compounds. The most plausible mechanism for the treatment of AD is the reduction of the amyloid beta-peptide (Abeta) plaques, one of the pathological markers of AD, in the brain. For this purpose, the inhibitors of beta-secretase and gamma-secretase, which cleave amyloid precursor protein (APP) to release Abeta, has been developed to interfere with APP processing. The beta-sheet breaker and metal chelators for the breakdown of aggregated Abeta have also been synthesized as well as the immunotherapeutic approach using Abeta vaccine. On the other hand, some nonsteroidal anti-inflammatory drugs, such as ibuprofen and sulindac, noncompetitively inhibited Abeta production but not Notch cleavage. The development of Abeta-lowering drugs is highly expected for the treatment of AD.
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Iwasaki Y, Ichikawa Y, Igarashi O, Konno S, Aoyagi J, Ikeda K, Marabuchi S, Ono S, Iguchi H, Kawabe K, Fujioka T. T-588 protects motor neuron death following axotomy. Neurochem Res 2004; 29:403-6. [PMID: 15002737 DOI: 10.1023/b:nere.0000013744.57398.fd] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
R(-)-1-(benzo [b] thiophen-5-yl)-2-[2-(N,N-diethylamino)ethoxy] ethanol hydrochloride) (T-588) enhances acetylcholine release. This compound slows the motor deterioration of wobbler mouse motor neuron disease and enhances neurite outgrowth and choline acetyltransferase activity in cultured rat spinal motor neurons. We examined the ability of T-588 on axotomized spinal motor neuron death in the rat spinal cord. After the postnatal unilateral section of sciatic nerve, there was approximately a 50% survival of motor neurons in the fourth lumbar segment. In comparison with vehicle, intraperitoneal injection of T-588 for 14 consecutive days rescued spinal motor neuron death. Our results showing in vivo neurotrophic activity of T-588 for motor neurons support the applicability of T-588 for the treatment of motor neuron diseases, such as amyotrophic lateral sclerosis and motor neuropathies.
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Affiliation(s)
- Yasuo Iwasaki
- Department of Neurology, Toho University Omori Hospital, Omori Ota-ku, Tokyo, Japan.
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Yamamuro A, Ago Y, Takuma K, Maeda S, Sakai Y, Baba A, Matsuda T. Possible involvement of astrocytes in neuroprotection by the cognitive enhancer T-588. Neurochem Res 2004; 28:1779-83. [PMID: 14649717 DOI: 10.1023/a:1026103304490] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
We have previously shown that the cognition enhancer (1R)-1-benzo[b]thiophen-5-yl-2-[2-(diethylamino)ethoxy]ethan-1-ol hydrochloride (T-588) protects astrocytes against hydrogen peroxide (H2O2) injury via activation of extracellular signal-regulated kinase (ERK) pathway. The present study examines whether the effect of T-588 on astrocytes contributes to neuroprotection in neuronal injury models. Astrocyte-conditioned medium (ACM) protected against neuronal injury induced by amyloid-beta protein (A beta) in cultured cortical neurons. The effect of ACM on A beta-induced injury was blocked by the ERK kinase inhibitor 2'-amino-3'-methoxyflavone. ACM stimulated ERK phosphorylation in cultured neurons. ACM derived from astrocytes exposed to H2O2 lost the activities to stimulate ERK phosphorylation and protect against neuronal injury. T-588 blocked the H2O2-induced loss of the activities of ACM. These results suggest that ACM protects against neuronal injury by an ERK-dependent mechanism, and the effect of T-588 on astrocytic injury results in neuroprotection.
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Affiliation(s)
- Akiko Yamamuro
- Laboratory of Medicinal Pharmacology, Graduate School of Pharmaceutical Sciences, Osaka University, Suita, Osaka, Japan
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Phuagphong P, Fukushima T, Hatanaka R, Tanaka K, Baba A, Matsuda T. T-588, a Cognitive Enhancer, Protects Against Sodium Nitroprusside-Induced Toxicity in Cultured Astrocytes. J Pharmacol Sci 2004; 95:135-8. [PMID: 15153661 DOI: 10.1254/jphs.95.135] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022] Open
Abstract
The effects of (1R)-1-benzo[b]thiophen-5-yl-2-[2-(diethylamino)ethoxy]ethan-1-ol hydrochloride (T-588), a cognitive enhancer, on sodium nitroprusside (SNP)-induced cytotoxicity were examined in cultured rat astrocytes. Treatment with 100 microM SNP for 72 h decreased cell viability and mitochondrial function assessed by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenil tetrazolium bromide (MTT) reduction activity, mitochondrial transmembrane potential, and intracellular ATP level. T-588 at 100 microM prevented SNP-induced mitochondrial dysfunction and cell injury. Furthermore, T-588 increased MTT reduction activity without affecting cell proliferation in astrocytes. These results suggest that T-588 has a protective effect against SNP-mediated toxicity via improvement of mitochondrial dysfunction in astrocytes.
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Affiliation(s)
- Patamawan Phuagphong
- Laboratory of Molecular Neuropharmacology, Graduate School of Pharmaceutical Sciences, Osaka University, Suita, Japan
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Iwasaki Y, Ichikawa Y, Igarasi O, Aoyagi J, Konno S, Ikeda K, Iguchi H, Kawabe S, Marubuchi S, Ono S. T-588 protects motor neuron death against glutamate-induced neurotoxicity. Neurochem Res 2003; 28:1829-32. [PMID: 14649724 DOI: 10.1023/a:1026167624054] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
To examine the possible neuroprotective effect of T-588 against glutamate-induced neurotoxicity, we analyzed the pharmacological utility of T-588 in a postnatal organotypic culture model of motor neuron degeneration. Treatment with 10(-5) M of glutamate resulted a motor neuron loss and decreased activity of choline acetyltransferase (ChAT). Cotreatment of 10(-5) M of glutamate and T-588 revealed a protective effect against motor neuron death and decreased ChAT activity. We concluded that T-588 may play important roles in the survival and maintenance of spinal motor neurons in its neuroprotection against glutamate-induced neurotoxicity. Our data may provide a rationale for designing a therapeutic strategy for protection against pathologically induced motor neuron damage or cell death such as amyotrophic lateral sclerosis and motor neuropathy.
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Affiliation(s)
- Yasuo Iwasaki
- Department of Neurology, Toho University Omori Hospital, Tokyo, Japan.
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Yokoyama I, Sakai Y, Hatayama Y, Tsuji S, Koyama Y, Baba A, Matsuda T. T-588, a cognitive enhancer, stimulates in vivo phosphorylation of extracellular signal-regulated kinases in the hippocampus. BRAIN RESEARCH. COGNITIVE BRAIN RESEARCH 2003; 17:522-5. [PMID: 12880921 DOI: 10.1016/s0926-6410(03)00142-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Administration of (1R)-1-benzo[b]thiophen-5-yl-2-[2-(diethylamino)ethoxy]ethan-1-ol hydrochloride (T-588), a cognitive enhancer, like the acetylcholine esterase inhibitors physostigmine and tacrine, stimulated phosphorylation of extracellular signal-regulated kinases (ERK) in the mouse hippocampus. The effect of T-588 on ERK phosphorylation was persistent from 2 to 6 h after injection. Immunohistochemical study showed that T-588 stimulated neuronal ERK phosphorylation in rat hippocampal CA1 pyramidal subfield. These findings suggest that systemic T-588 stimulates the ERK kinase pathway in the hippocampal neurons.
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Affiliation(s)
- Ikuko Yokoyama
- Laboratory of Medicinal Pharmacology, Graduate School of Pharmaceutical Sciences, Osaka University, Suita, Osaka 565-0871, Japan
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Yamamuro A, Ago Y, Maeda S, Sakai Y, Baba A, Matsuda T. Protective effect of T-588 on toxic damage by serum deprivation and amyloid-beta protein in cultured neurons. J Pharmacol Sci 2003; 92:153-6. [PMID: 12832844 DOI: 10.1254/jphs.92.153] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022] Open
Abstract
The present study examines the effect of the cognition enhancer (1R)-1-benzo[b]thiophen-5-yl-2-[2-(diethylamino)ethoxy]ethan-1-ol hydrochloride (T-588) on neuronal injury induced by serum deprivation or amyloid-beta protein (A beta). T-588 protected partially against neuronal injury induced by serum deprivation or A beta in cultured cortical neurons. T-588 did not affect the phosphorylation of extracellular signal-regulated kinase (ERK) in cortical neurons and SH-SY5Y cells. These results suggest that T-588 has a protective effect in neuronal injury models and the effect is not mediated by an ERK signal pathway.
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Affiliation(s)
- Akiko Yamamuro
- Laboratory of Medicinal Pharmacology, Graduate School of Pharmaceutical Sciences, Osaka University
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Iwasaki Y, Ikeda K, Ichikawa Y, Igarashi O, Kinoshita M, Marubuchi S, Ono S. T-588 enhances neurite outgrowth and choline acetyltransferase in cultured rat spinal ventral horn neurons. Neurochem Res 2002; 27:225-8. [PMID: 11958520 DOI: 10.1023/a:1014884504879] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
T-588(R(-)-1-(benzo(b)thiophen-5yl)-2-[2(N,N-diethylamino)ethoxy]ethanol hydrochloride) is a novel compound which has been shown to exhibit a wide range of neurotrophic effects both in vivo and in vitro. This compound can slow the motor deterioration of wobbler mouse motor neuron disease. However, it is not known whether this compound has a trophic effect on spinal motor neurons. We have studied the effect of T-588 on neurite outgrowth and choline acetyltransferase(ChAT) activity in primary explant cultures of ventral spinal cord of fetal rats(VSCC). Cultures were treated with T-588 from day 1 to 1 week. T-588 treated VSCC, compared with control VSCC, had a significant neurite promoting effect at ranged between 10(-8) molar(M) and 10(-5) M, with 2.3 to 5.3 fold increased over that of control VSCC. In T-588 treated VSCC, ChAT activity was increased 1.5 times over that of control at 10(-6), and 10(-5) M respectively. Our data showing T-588 has neurotrophic action on VSCC and suggests a potential use of T-588 in treating diseases that involve degeneration and death of spinal motor neurons, such as motor neuropathy and motor neuron disease.
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Affiliation(s)
- Yasuo Iwasaki
- Fourth Department of Internal Medicine, Toho University Ohashi Hospital, Tokyo, Japan.
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Nakada Y, Tamura R, Kuriwaki J, Kimura T, Uwano T, Nishijo H, Ono T. Ameliorative effects of a cognitive enhancer, T-588, on place learning deficits induced by transient forebrain ischemia in rats. Physiol Behav 2001; 74:227-35. [PMID: 11564472 DOI: 10.1016/s0031-9384(01)00576-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
In the present study, we investigated the effect of (1R)-1-benzo[b]thiophen-5-yl-2-[2-(diethylamino)ethoxy]ethan-1-ol hydrochloride (T-588), a newly synthesized cognitive enhancer, on place learning deficits in rats with damage selective to the hippocampal CA1 subfield induced by transient forebrain ischemia. Three weeks after the ischemic insult, T-588 was daily administered (0.3 or 3.0 mg/kg/day po). Place learning was tested in a task in which the rat was required to alternatively visit two places located diametrically opposite each other in an open field. The ischemic rats without the treatment of T-588 displayed severe learning impairment in this task; their performance level was significantly inferior to that of the sham-operated rats. The treatment of T-588 improved dose-dependently the task performance in ischemic rats, although no apparent protective effects on ischemic damage were found histologically. These results suggested that T-588 has ameliorative effects on learning deficits induced by brain ischemia, which could be produced through enhancement of residual cognitive functions.
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Affiliation(s)
- Y Nakada
- Department of Physiology, Faculty of Medicine, Toyama Medical and Pharmaceutical University, 2630 Sugitani, 930-0194, Toyama, Japan
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Maekawa M, Murayama T, Nomura Y. Involvement of noradrenaline transporters in S-nitrosocysteine-stimulated noradrenaline release from rat brain slices: existence of functional Na(+)-independent transporter activity. Neurochem Int 2001; 38:323-31. [PMID: 11137627 DOI: 10.1016/s0197-0186(00)00097-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Noradrenaline (NA) can be released by both exocytosis and by the membrane transporter responsible for transmitter uptake. Previously, we reported that S-nitrosocysteine (SNC), an S-nitrosothiol, stimulated [3H]NA release from the rat hippocampus. In this study, we investigated the involvement of the NA transport system in SNC-stimulated NA release from rat brain (cerebral cortex and hippocampus) slices. [3H]NA release by SNC in normal Na(+) (148 mM)-containing buffer from both slices was slightly, but significantly, inhibited by 1 microM desipramine, an NA transporter inhibitor. [3H]NA release in low Na(+) (under 14 mM)-containing buffer was inhibited by over 50% by desipramine. [3H]NA release by tyramine from both slices in normal and low Na(+) buffer was almost completely inhibited by desipramine. [3H]NA uptake into cerebral cortical slices was observed in low Na(+) buffer at 20-30% of normal Na(+) buffer levels. [3H]NA uptake in both normal and low Na(+) buffers was inhibited by desipramine and by SNC. Although [3H]NA uptake in normal Na(+) buffer was almost completely inhibited by 500 microM ouabain, the uptake in low Na(+) buffer was resistant to ouabain. These findings suggest the existence of a functional Na(+)-independent NA transport system and that SNC stimulates NA release at least partially via this system in brain slices.
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Affiliation(s)
- M Maekawa
- Department of Pharmacology, Graduate School of Pharmaceutical Sciences, Hokkaido University, 060-0812, Sapporo, Japan
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Takuma K, Fujita T, Kimura Y, Tanabe M, Yamamuro A, Lee E, Mori K, Koyama Y, Baba A, Matsuda T. T-588 inhibits astrocyte apoptosis via mitogen-activated protein kinase signal pathway. Eur J Pharmacol 2000; 399:1-8. [PMID: 10876016 DOI: 10.1016/s0014-2999(00)00334-4] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The effect of (1R)-1-benzo[b]thiophen-5-yl-2-[2-(diethylamino)ethoxy]ethan -1-ol hydrochloride (T-588), a cognition enhancer, on reperfusion injury was studied in cultured rat astrocytes. T-588 at 1-10 microM partially protected astrocytes against reperfusion injury after exposure to Ca(2+)-free medium or hydrogen peroxide. Nerve growth factor (NGF) had a similar protective effect. Addition of both T-588 and NGF resulted in complete protection against Ca(2+) reperfusion injury. T-588 did not stimulate NGF production in astrocytes. The effect of T-588 on Ca(2+) reperfusion injury including apoptosis was inhibited by the mitogen-activated protein (MAP)/extracellular signal-regulated kinase (ERK) kinase inhibitor 2'-amino-3'-methoxyflavone (PD98059), but not by the phosphoinositide 3-kinase inhibitor wortmannin. The effect of NGF was inhibited by PD98059 and wortmannin. T-588 stimulated rapidly the phosphorylation of ERK, but did not affect that of Akt in astrocytes. These findings suggest that the ERK MAP kinase pathway has a role in the protective effects of T-588 and NGF.
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Affiliation(s)
- K Takuma
- Department of Analytical Chemistry, Faculty of Pharmaceutical Sciences, Kobe Gakuin University, 518 Arise, Ikawadani-cho, Nishi-ku, 651-2180, Kobe, Japan
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Maekawa M, Satoh S, Murayama T, Nomura Y. Involvement of Hg2+-sensitive sulfhydryl groups in regulating noradrenaline release induced by S-nitrosocysteine in rat brain slices. Biochem Pharmacol 2000; 59:839-45. [PMID: 10718342 DOI: 10.1016/s0006-2952(99)00397-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Nitric oxide has been shown to regulate neurotransmitter release. Previously, we reported that S-nitrosothiols such as S-nitrosocysteine (SNC) stimulate noradrenaline (NA) release in rat hippocampus in vivo and in vitro. To examine the role of sulfhydryl groups in SNC-induced NA release, the effects of metal ions such as Hg2+ and N-ethylmaleimide (NEM, a sulfhydryl alkylating agent) on [3H]NA release from labeled rat brain slices (hippocampus and cerebral cortex) were studied and compared with the effects of SNC. The addition of 200 microM HgCl2, but not Pb2+, Zn2+, or Cd2+, stimulated [3H]NA release from both types of slices in the presence of extracellular CaCl2. p-Chloromercuribenzoic acid (p-CMBA) also stimulated [3H]NA release. NEM stimulated [3H]NA release from both types of slices in the presence and absence of extracellular CaCl2. The effect of 200 microM NEM was enhanced, but the effect of 200 microM SNC was inhibited by co-addition of 200 microM p-CMBA in the absence of extracellular CaCl2. The concentration-response curve of SNC shifted to the right after co-addition of 200 microM p-CMBA or 100 microM HgCl2, although the effect of 200 microM NEM was additive to the effect of SNC. These findings demonstrate that SNC acts as a sulfhydryl agent on proteins that regulate NA release, and that SNC may share the same sulfhydryl groups with Hg compounds. The effect of T-588 ¿(R)-(-)-(benzo[b]thiophen-5-yl)-2-[2-(N,N-diethylamino)ethoxy]eth anol hydrochloride¿, a novel cognitive enhancer and a stimulator of NA release, was compared with the effects of sulfhydryl reagents.
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Affiliation(s)
- M Maekawa
- Department of Pharmacology, Graduate School of Pharmaceutical Sciences, Hokkaido University, Sapporo, Japan
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Ikeda K, Iwasaki Y, Kinoshita M, Marubuchi S, Ono S. T-588, a novel neuroprotective agent, delays progression of neuromuscular dysfunction in wobbler mouse motoneuron disease. Brain Res 2000; 858:84-91. [PMID: 10700601 DOI: 10.1016/s0006-8993(99)02427-0] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
R(-)-1-(benzo[b]thiophen-5-yl)-2-[2-(N,N-diethylamino) ethoxy]ethanol hydrochloride (T-588) enhances acetylcholine release from the frontal cortex and hippocampus in rats, and can ameliorate cognitive dysfunction in various amnesia models of rodents. T-588 protects rat cerebellar granule cells from glutamate neurotoxicity in culture. This agent also inhibits facilitation in the crayfish neuromuscular junction and mammalian cerebellum. Clinical trials of T-588 are underway in patients with Alzheimer's disease. We attempted to determine whether T-588 treatment ameliorates neuromuscular dysfunction in the wobbler mouse, an animal model of motoneuron disease (MND). After the initial diagnosis of MND at the age of 3-4 weeks, wobbler mice were orally administered T-588 (3, 10, 30 mg/kg) or vehicle daily for 4 weeks in a blinded fashion. We compared symptomatic, pathological and biochemical changes among the groups. In comparison with vehicle, T-588 administration potentiated grip strength, attenuated forelimb contracture and increased the weight of the biceps muscles. T-588-treated mice had retarded denervation muscle atrophy and elevated activities of choline acetyltransferase (ChAT) or lactate dehydrogenase in the biceps muscles. T-588 treatment also enhanced ChAT activities and promoted formation of cyclic adenosine monophosphate in the cervical cord. Pharmacokinetic study also showed that T-588 was transported efficiently into the cerebrum and spinal cord following oral administration. Thus, T-588 treatment delayed the progression of wobbler murine MND. Our findings suggest that this agent has therapeutic potential in human motor neuropathy or MND.
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Affiliation(s)
- K Ikeda
- Fourth Department of Internal Medicine, Toho University Ohashi Hospital, 2-17-6, Ohashi, Meguro-ku, Tokyo, Japan
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Maekawa M, Ono S, Narita H, Murayama T, Nomura Y. Stimulation of noradrenaline release by T-588, a cognitive enhancer, in PC12 cells. JAPANESE JOURNAL OF PHARMACOLOGY 2000; 82:59-66. [PMID: 10874590 DOI: 10.1254/jjp.82.59] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Previously, we reported that (R)-(-)-1-(benzo[b]thiophen-5-yl)-2-[2-(N,N- diethylamino)ethoxy] ethanol hydrochloride (T-588), a novel putative cognitive enhancer, stimulated noradrenaline (NA) release from rat cerebral cortical slices. In this study, we investigated the effects of T-588 compared to other secretagogues on NA release from PC12 cells. Addition of as little as 10 microM T-588 stimulated [3H]NA release in a dose-dependent and an extracellular Ca(2+)-independent manner from PC12 cells. Ten micromolar ionomycin-, 300 microM adenosine-5'-O-(gamma-thiotriphosphate)- and 10 microM forskolin-induced extracellular Ca(2+)-dependent [3H]-NA release was further enhanced by 30 microM T-588. Cytosolic synaptophysin and 25-kDa synaptosome-associated protein immunoreactivity was increased by addition of T-588 in a dose-dependent manner. Interestingly, increases in synaptic vesicle-related proteins triggered by T-588 had a 4-min lag time and were completely dependent on extracellular CaCl2. These findings suggest that T-588 stimulates NA release from PC12 cells in a Ca(2+)-independent manner. T-588 also induced the translocation of synaptic vesicles in a Ca(2+)-dependent manner.
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Affiliation(s)
- M Maekawa
- Department of Pharmacology, Graduate School of Pharmaceutical Sciences, Hokkaido University, Sapporo, Japan
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Zhang TY, O'toole J, Proctor CS. Recent Advances in the Synthesis and Applications of Benzo[b]thiophenes. ACTA ACUST UNITED AC 1999. [DOI: 10.1080/01961779908047953] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Kimura T, Tamura R, Kurimoto H, Ono T. Effects of T-588, a newly synthesized cognitive enhancer, on hippocampal CA1 neurons in rat brain tissue slices. Brain Res 1999; 831:175-83. [PMID: 10411997 DOI: 10.1016/s0006-8993(99)01450-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
The effects of a newly synthesized cognitive enhancer, (-)-R-alpha-[[2-(diethylamino) ethoxy] methyl] benzo [b] thiophene-5-methanol hydrochloride (T-588), on the membrane properties of hippocampal CA1 neurons were investigated in a rat brain slice preparation. T-588 produced a slow and long-lasting depolarization of CA1 neurons with an increase in membrane resistance; this action showed close similarity to that of acetylcholine (ACh). However, the action of T-588 was not affected by atropine, tetrodotoxin or DL-2-amino-5-phosphonovalerate, while the action of ACh was blocked by atropine. The estimated reversal potential of this T-588 effect was near -90 mV which is the reversal potential of potassium ions in CA1 neurons. In the whole-cell voltage-clamp study, T-588 produced a reversible block of the outward potassium current in CA1 neurons. T-588 did not block the afterhyperpolarization evoked by an intracellular current injection, while ACh suppressed it. These results suggest that T-588 has a direct effect on CA1 neurons independent of its cholinergic activity, resulting from blockade of a conductance carried predominantly by potassium ions.
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Affiliation(s)
- T Kimura
- Department of Physiology, Faculty of Medicine, Toyama Medical and Pharmaceutical University, 2630 Sugitani, Toyama 930-0194, Japan
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Maekawa M, Miyazaki H, Ono S, Narita H, Murayama T, Nomura Y. Effects of T-588, a novel cognitive enhancer, on ADP-ribosylation of G(s alpha) by cholera toxin and cyclic AMP accumulation in rat cerebral cortex. Neurochem Int 1999; 34:149-55. [PMID: 10213074 DOI: 10.1016/s0197-0186(98)00082-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
We investigated the effects of R(-)-1-(benzo[b]thiophen-5-yl)-2-[2-(N,N-diethylamino)ethoxy]ethan ol hydrochloride (T-588), a novel cognitive enhancer, on trimeric GTP-binding proteins (G proteins) and cyclic AMP accumulation in rat cerebral cortex. T-588 (0.1-1.0 mM) inhibited the ADP-ribosylation of alpha subunit of Gs in a concentration-dependent manner. Auto-ADP-ribosylation of CTX was not inhibited by T-588. The stimulatory effect of guanosine 5'-(3-O-thio)triphosphate (GTPgammaS) on CTX-catalyzed ADP-ribosylation was attenuated by adding T-588 in assay mixture. ADP-ribosylation of Gi/Go by pertussis toxin was slightly inhibited by T-588. Isoproterenol-stimulated cyclic AMP accumulation was inhibited by adding 3 mM T-588 to rat cerebral cortical slices. Next, we investigated the effects of isoproterenol and T-588 on GTPgammaS binding. Membranes were first incubated with or without isoproterenol and T-588 in the presence of 0.2mM GTPgammaS, then cholate extract preparations were prepared from the washed membranes. Interestingly, the [32P]ADP-ribosylation of G(s alpha) was enhanced not only by isoproterenol but also by T-588. Although the obtained results are apparently inconsistent, T-588 seems to interact with G proteins, specifically Gs.
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Affiliation(s)
- M Maekawa
- Department of Pharmacology, Graduate School of Pharmaceutical Sciences, Hokkaido University, Sapporo, Japan
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Maekawa M, Murayama T, Ono S, Narita H, Nomura Y. The effects of T-588, a novel cognitive enhancer, on noradrenaline uptake and release in rat cerebral cortical slices. JAPANESE JOURNAL OF PHARMACOLOGY 1998; 77:155-60. [PMID: 9681572 DOI: 10.1254/jjp.77.155] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Previously, we reported that (R)-(-)-1-(benzo[b]thiophen-5-yl)-2-[2-(N,N-diethylamino)-ethoxy]e thanol hydrochloride (T-588), a novel cognitive enhancer, stimulated noradrenaline (NA) release from rat cerebral cortical slices. In this study, we investigated the effects of T-588 on NA uptake and release, compared to the effects of desipramine, a blocker of the NA carrier on the plasma membrane. Both T-588 and desipramine caused dose-dependent inhibition of [3H]NA uptake into the slices. Addition of 3 mM T-588 stimulated [3H]NA release from the prelabeled slices even in the presence of 10 microM desipramine, which inhibited NA uptake completely. Tyramine, which accelerates NA carrier-mediated release, also stimulated [3H]NA release, and tyramine-stimulated release was inhibited by desipramine. These findings indicated that T-588-stimulated NA release was not mediated by 1) inhibition of reuptake or 2) reverse transport mediated by NA carriers. Reserpine, which interacts with the intracellular vesicular transport system, increased [3H]NA efflux from slices. High K+-, not T-588-, stimulated [3H]NA release was shifted upward by reserpine. These findings suggest that T-588 evokes NA release by a mechanism similar to that induced by reserpine. T-588 might act as a cognitive enhancer via neurotransmitter release in the brain.
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Affiliation(s)
- M Maekawa
- Department of Pharmacology, Faculty of Pharmaceutical Sciences, Hokkaido University, Sapporo, Japan
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Miyazaki H, Murayama T, Ono S, Narita H, Nomura Y. Effects of R(-)-1-(benzo[b]thiophen-5-yl)-2-[2-N,N-diethylamino)ethoxy]ethan ol hydrochloride (T-588), a novel cognitive enhancer, on noradrenaline release in rat cerebral cortical slices. Biochem Pharmacol 1997; 53:1263-9. [PMID: 9214687 DOI: 10.1016/s0006-2952(97)00020-8] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
We investigated the effects of R(-)-1-(benzo[b]thiophen-5-yl)-2-[2-(N,N-diethylamino)ethoxy]ethan ol hydrochloride (T-588), a novel cognitive enhancer, on noradrenaline (NA) release from rat cerebral cortical slices in vitro. Addition of T-588 in an assay mixture stimulated [3H]NA release from prelabeled slices in the presence or absence of extracellular CaCl2, and in the presence of the Ca2+/calmodulin antagonists N-(6-aminohexyl)-5-chloro-1-naphthalenesulfonamide and trifluoperazine. T-588 stimulated NA release with a time lag of about 1 min, and the high level of release was maintained for at least 10 min, whereas maximal KCl-evoked NA release was observed within 1 min after the addition of KCl, and the effect declined subsequently. The effect of T-588 was reversible (pretreatment with T-588 showed no effect on NA release after two washes by centrifugation). We also compared the effects of T-588 and N-ethylmaleimide (NEM), a sulfhydryl alkylating agent known to stimulate neurotransmitter release in several types of cells. The addition of NEM stimulated NA release irreversibly from the slices in a Ca2+-independent manner, and the effect of NEM, but not that of T-588, was inhibited by the simultaneous addition of dithiothreitol, a sulfhydryl group reducing agent. The addition of T-588, which stimulated NA release by itself, inhibited the NA release by 0.6 mM NEM, although the effect of T-588 was additive in the presence of 0.2 mM NEM. These findings suggest that T-588 stimulates NA release from rat cerebral cortical slices in a Ca2+- and calmodulin-independent manner, possibly via an NEM-sensitive factor(s), although the mechanism of the effects of T-588 seems to be different from that of NEM.
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Affiliation(s)
- H Miyazaki
- Department of Pharmacology, Faculty of Pharmaceutical Sciences, Hokkaido University, Sapporo, Japan
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