著者

Fukie Niijima-Yaoita Masahiro Tsuchiya Hiroshi Ohtsu Kazuhiko Yanai Shunji Sugawara Yasuo Endo Takeshi Tadano

出版者

The Pharmaceutical Society of Japan

雑誌

Biological and Pharmaceutical Bulletin (ISSN:09186158)

巻号頁・発行日

vol.35, no.1, pp.91-97, 2012-01-01 (Released:2012-01-05)

参考文献数

35

被引用文献数

29 30

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Exercise necessitates a large supply of O2 and nutrients and rapid removal of CO2 and waste products. Histamine is a regulator of the microcirculation (which performs these exchanges), suggesting a possible involvement of histamine in exercise. Histamine is released from either mast cells or non-mast cells. In the latter, histamine is newly formed via the induction of histidine decarboxylase (HDC) in response to an appropriate stimulus, and it is released without being stored. Here, in mice, we examined the role of histamine or HDC induction in exercise. Prolonged walking (PW) (in a cylindrical cage turned electrically) increased HDC mRNA and HDC activity in quadriceps femoris muscles. Mice given a histamine H1-receptor antagonist [fexofenadine (peripherally acting) or pyrilamine (peripherally and centrally acting)] or an irreversible HDC inhibitor (α-fluoromethylhistidine) displayed less PW endurance than control mice. Ranitidine (H2-receptor antagonist) tended to reduce endurance. Other histamine-receptor (H3 and H4) antagonists had no significant effects on endurance. Mice deficient in HDC or histamine H1-receptors displayed markedly less endurance than control mice, and HDC activity in the quadriceps femoris of H1-deficient mice was rapidly elevated by PW. Fexofenadine significantly reduced the muscle levels of nitric oxide (NO) metabolites and glycogen after PW. The results support the ideas that (i) histamine is involved in protecting against exercise-induced fatigue or exhaustion, (ii) histamine exerts its protective effect via H1 receptors and the ensuing production of NO in skeletal muscle, and (iii) histamine is provided, at least in part, by HDC induction in skeletal muscles during prolonged exercise.

著者

Kotaro Hiraoka Hitoshi Inada Kazuhiko Yanai Noriko Osumi

出版者

Tohoku University Medical Press

雑誌

The Tohoku Journal of Experimental Medicine (ISSN:00408727)

巻号頁・発行日

vol.252, no.3, pp.199-208, 2020 (Released:2020-10-22)

参考文献数

19

被引用文献数

3

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Ependymal cells have an essential role in regulating the dynamics of the cerebrospinal fluid flow by the movement of their multiple cilia. Impaired generation or function of cilia could cause hydrocephalus due to the disordered dynamics of the cerebrospinal fluid flow. However, molecular bases regulating differentiation of the ependymal cells and their ciliogenesis have not been fully elucidated. We report here that bone morphogenetic proteins (BMPs), growth factors orchestrating tissue architecture throughout the body, inhibit ciliogenesis during ependymal cell differentiation in primary cell culture. Previous in vitro study has reported that ectopic expression of Smad6 and Smad7 promotes differentiation of embryonic stem cells into multi-ciliated ependymal-like cells. Since Smad6 and Smad7 have been known as the intracellular inhibitory factors of the BMP signaling pathway, the activation of the pathway could cause a deficit in ciliogenesis of ependymal cells. To examine whether activation of the pathway affects ciliogenesis, we investigated the effects of two BMPs, BMP2 and BMP4, on the ependymal differentiation of the primary cultured cells prepared from the neonatal mouse brain. Supplementation of BMP2 or BMP4 in culture media significantly reduced the number of cells with multiple cilia among the total cells, while most of the cells expressed FoxJ1, a master regulator of ciliogenesis. Activation of the pathway was confirmed by the phosphorylation of intracellular Smad1/5/8, downstream factors of the BMP receptors. These in vitro results suggest that inhibition of the BMP signaling pathway might be essential for ciliogenesis during the ependymal cell differentiation in vivo.

著者

Masaaki Tagawa Michiko Kano Nobuyuki Okamura Masatoshi Itoh Eiko Sakurai Takehiko Watanabe Kazuhiko Yanai

出版者

The Japanese Pharmacological Society

雑誌

The Japanese Journal of Pharmacology (ISSN:00215198)

巻号頁・発行日

vol.83, no.3, pp.253-260, 2000 (Released:2001-01-31)

参考文献数

46

被引用文献数

16 14

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Ethanol is a social drug and has been generally known to be a CNS depressant.A large fluctuation of blood alcohol concentration(BAC)is well−known to occur due to main factors such as the genetic polymorphism of the main alcohol metabolizing enzymes and the effect of blood.Few studies have substantially discussed the relationship between impaired CNS activities and BAC.In this study, focusing on the correlation of BAC, we investigated the acute effects of alcohol intake on cognitive performance in humans by objective evaluation methods consisting of the attention−demanding cognitive tasks.Tasks were administered to ten healthy male volunteers before and after ingesting established amounts of alcohol.With increased BAC, we observed prolongation of reaction time performances and lowering of a coordination performance.From the results, we concluded that cognitive performance deteriorates with an increase of BAC.Additionally, the BAC threshold that causes significant impairment of cognitive performance was estimated to be approximately 50 mg/dl(ca.10 mM).

著者

Tomohiro Okuda Dongying Zhang He Shao Nobuyuki Okamura Naoko Takino Tatsunori Iwamura Eiko Sakurai Takeo Yoshikawa Kazuhiko Yanai

出版者

The Japanese Pharmacological Society

雑誌

Journal of Pharmacological Sciences (ISSN:13478613)

巻号頁・発行日

vol.111, no.2, pp.167-174, 2009 (Released:2009-10-15)

参考文献数

26

被引用文献数

17 27

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Histamine H3 receptors inhibit the release of not only histamine itself, but also other neurotransmitters including dopamine. Previous papers have reported that histaminergic neurons inhibit psychostimulant-induced behavioral changes. To examine whether deficiency in histamine H3 receptors influences psychostimulant-induced behavioral sensitization and reward, we examined locomotor activity, conditioned place preference (CPP), and c-Fos expression in histamine H3 receptor–gene knockout mice (H3KO) and their wild-type (WT) counterparts before and after treatment with methamphetamine (METH) and 3,4-methylenedioxymethamphetamine (MDMA). The increase in locomotion induced by treatment with METH or MDMA was lower in histamine H3KO mice than in WT mice, while the locomotor sensitization was developed by METH or MDMA in both strains. However, no significant difference in METH- and MDMA-induced preference scores of CPP between histamine H3KO mice and WT mice was observed. Following treatment with METH, the number of c-Fos–positive neurons in the the caudate-putamen of histamine H3KO mice was lower than that in the caudate-putamen of WT mice. In contrast, there was no significant difference in the number of the psychostimulant-induced c-Fos–positive cells in the nucleus accumbens between the two strains of mice. These findings suggest that deficiency in histamine H3 receptors may have inhibitory effects on psychostimulant-induced increase in locomotion, but insignificant effects on the reward.

著者

Ai Yanai Masatoshi Itoh Hisashi Hirakawa Kazuhiko Yanai Manabu Tashiro Ryuichi Harada Akira Yoshikawa Seiichi Yamamoto Noriaki Ohuchi Takanori Ishida

出版者

Tohoku University Medical Press

雑誌

The Tohoku Journal of Experimental Medicine (ISSN:00408727)

巻号頁・発行日

vol.245, no.1, pp.13-19, 2018 (Released:2018-05-03)

参考文献数

22

被引用文献数

6

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Positron emission mammography (PEM) has higher detection sensitivity for breast cancer compared with whole-body positron emission tomography (PET) due to higher spatial resolution. We have developed a new PEM device with high resolution over a wide field of view. This PEM device comprises novel scintillation crystals, praseodymium-doped lutetium aluminum garnet (Pr:LuAG). In the present study, the clinical use of the newly developed PEM for the detection of small breast cancer was compared with that of the conventional PET-computed tomography (PET/CT). Eighty-two patients with breast cancer less than 20 mm (UICC T1) participated in this study, including 23 patients with T1a or T1b breast cancer (less than 10 mm). Histologically-proved lesions were examined by PET/CT and PEM on the same day after injection of [18F]fluoro-2-deoxy-2-fluoro-D-glucose ([18F]FDG), a marker of glycolytic activity. The newly developed PEM showed better sensitivity of cancer detection compared with PET/CT especially in case of the small T1a or T1b lesions. Moreover, when the conventional PET/CT and new PEM were combined, the detection sensitivity with [18F]FDG molecular imaging for T1 (N = 82) and T1a plus T1b breast cancer (N = 23) were 90% and 70%, respectively. The uptake of [18F]FDG was proportional to the histological malignancy of breast cancer. Using the newly-developed PEM with [18F]FDG, we are able to identify and characterize exactly the small breast tumors less than 10 mm in combination with the conventional PET/CT. These data indicate that PEM and PET/CT are synergic and complementary for the detection of small breast cancer.