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171 results on '"Shiraishi, Mitsuya"'

18. Cytochrome P450 2J Genes Are Expressed in Dogs, Cats, and Pigs, and Encode Functional Drug-Metabolizing Enzymes

Author

Uno, Yasuhiro, primary, Murayama, Norie, additional, Ijiri, Moe, additional, Kawaguchi, Hiroaki, additional, Yamato, Osamu, additional, Shiraishi, Mitsuya, additional, Asano, Atsushi, additional, Teraoka, Hiroki, additional, Mizukawa, Hazuki, additional, Nakayama, Shouta M.M., additional, Ikenaka, Yoshinori, additional, Ishizuka, Mayumi, additional, and Yamazaki, Hiroshi, additional

Published
2022
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23. Comparative analysis of in vitro neurotoxicity of methylmercury, mercury, cadmium, and hydrogen peroxide on SH-SY5Y cells

Author

SUDO, Kasumi, VAN DAO, Cuong, MIYAMOTO, Atsushi, and SHIRAISHI, Mitsuya

Subjects
Pharmacology, Full Paper, L-Lactate Dehydrogenase, Cell Survival, Apoptosis, Heavy Metal Poisoning, Nervous System, Hydrogen Peroxide, Mercury, heavy metal, Methylmercury Compounds, Acetylcysteine, SH-SY5Y cell, Oxidative Stress, cell death, Cell Line, Tumor, Metals, Heavy, neurotoxicity, ROS generation, Humans, Reactive Oxygen Species, Cadmium
Abstract

Mercury (Hg) and cadmium (Cd) are the major toxic heavy metals and are known to induce neurotoxicity. Although many studies have shown that several heavy metals have neurotoxic effects, the cellular and molecular mechanisms thereof are still not clear. Oxidative stress is reported to be a common and important mechanism in cytotoxicity induced by heavy metals. However, the assays for identifying toxic mechanisms were not performed under the same experimental conditions, making it difficult to compare toxic properties of the heavy metals. In this study, we investigated the mechanisms underlying neurotoxicity induced by heavy metals and H2O2, focusing on cell death, cell proliferation, and oxidative stress under the same experimental condition. Our results showed that MeHg caused lactate dehydrogenase (LDH) release, caspase activation and cell-cycle alteration, and ROS generation in accordance with decreased cell viability. HgCl2 caused LDH release and cell-cycle alteration, but not caspase activation. CdCl2 had a remarkable effect on the cell cycle profiles without induction of LDH release, caspase activation, or ROS generation. Pretreatment with N-acetyl-l-cysteine (NAC) prevented the decrease in cell viability induced by MeHg and HgCl2, but not CdCl2. Our results demonstrate a clear difference in neurotoxic mechanisms induced by MeHg, HgCl2, CdCl2 or H2O2 in SH-SY5Y cells. Elucidating the characteristics and mechanisms of each heavy metal under the same experimental conditions will be helpful to understand the effect of heavy metals on health and to develop a more effective therapy for heavy metal poisoning.

Published
2019

25. A highly sensitive technique to measure myosin regulatory light chain phosphorylation: the first quantification in renal arterioles

Author

Takeya, Kosuke, Loutzenhiser, Kathy, Shiraishi, Mitsuya, Loutzenhiser, Rodger, and Walsh, Michael P.

Subjects
Myosin -- Physiological aspects, Myosin -- Health aspects, Myosin -- Research, Phosphorylation -- Physiological aspects, Phosphorylation -- Health aspects, Phosphorylation -- Research, Renal artery -- Physiological aspects, Renal artery -- Health aspects, Renal artery -- Research, Biological sciences
Abstract

Phosphorylation of the 20-kDa myosin regulatory light chains ([LC.sub.20]) plays a key role in the regulation of smooth muscle contraction. The level of [LC.sub.20] phosphorylation is governed by the relative activities of myosin light chain kinase and phosphatase pathways. The regulation of these two pathways differs in different smooth muscle types and in the actions of different vasoactive stimuli. Little is known concerning the regulation of [LC.sub.20] phosphorylation in the renal microcirculation. The available pharmacological probes are often nonspecific, and current techniques to directly measure [LC.sub.20] phosphorylation are not sensitive enough for quantification in small arterioles. We describe here a novel approach to address this important issue. Using SDS-PAGE with polyacrylamide-bound [Mn.sup.2+]-phosphate-binding tag and enhanced Western blot analysis, we were able to detect [LC.sub.20] phosphorylation using as little as 5 pg (250 amol) of isolated [LC.sub.20]. Phosphorylated and unphosphorylated [LC.sub.20] were detected in single isolated afferent arterioles, and [LC.sub.20] phosphorylation levels could be accurately quantified in pooled samples of three arterioles ( afferent arteriole; Phos-tag SDS-PAGE

Published
2008

27. Modulation of PG[F.sub.2[alpha]]-and hypoxia-induced contraction of rat intrapulmonary artery by p38 MAPK inhibition: a nitric oxide-dependent mechanism

Author

Knock, Greg A., De Silva, Anushika S., Snetkov, Vladimir A., Siow, Richard, Thomas, Gavin D., Shiraishi, Mitsuya, Walsh, Michael P., Ward, Jeremy P.T., and Aaronson, Philip I.

Subjects
Nitric oxide -- Chemical properties, Nitric oxide -- Research, Hypoxia -- Research, Mitogens -- Research, Protein kinases -- Research, Biological sciences
Abstract

The mechanisms through which p38 mitogen-activated protein kinase (p38 MAPK) is involved in smooth muscle contraction remain largely unresolved. We examined the role of p38 MAPK in prostaglandin [F.sub.2[alpha]] (PG[F.sub.2[alpha]])-induced vasoconstriction and in hypoxic pulmonary vasoconstriction (HPV) of rat small intrapulmonary arteries (IPA). The p38 MAPK inhibitors SB-203580 and SB-202190 strongly inhibited PG[F.sub.2[alpha]]-induced vasoconstriction, with I[C.sub.50]s of 1.6 and 1.2 [micro]M, whereas the inactive analog SB-202474 was ~30-fold less potent. Both transient and sustained phases of HPV were suppressed by SB-203580, but not by SB-202474 (both 2 [micro]M). Western blot analysis revealed that PG[F.sub.2[alpha]] (20 [micro]M) increased phosphorylation of p38 MAPK and of heat shock protein 27 (HSP27), and this was abolished by SB-203580 but not by B-202474 (both 2 [micro]M). Endothelial denudation or blockade of endothelial nitric oxide (NO) synthase with [N.sup.[omega]]-nitro-L -arginine methyl ester (L-NAME) significantly suppressed the relaxation of PG[F.sub.2[alpha]]-constricted IPA by SB-203580, but not by SB-202474. Similarly, the inhibition of HPV by SB-203580 was prevented by prior treatment with L-NAME. SB-203580 (2 [micro]M), but not SB-202474, enhanced relaxation-induced by the NO donor S-nitroso-N-acetylpenicillamine (SNAP) in endothelium-denuded IPA constricted with PG[F.sub.2[alpha]]. In [alpha]-toxin-permeabilized IPA, SB-203580-induced relaxation occurred in the presence but not the absence of the NO donor sodium nitroprusside (SNP); SB-202474 was without effect even in the presence of SNP. In intact IPA, neither PG[F.sub.2[alpha]] nor SNAP-mediated changes in cytosolic free [Ca.sup.2+] were affected by SB-203580. We conclude that p38 MAPK contributes to PG[F.sub.2[alpha]]- and hypoxia-induced constriction of rat IPA primarily by antagonizing the underlying [Ca.sup.2+]- desensitizing actions of NO. p38 mitogen-activated protein kinase; pulmonary artery; prostaglandin [F.sub.2[alpha]]; intracellular calcium; calcium sensitization; heat shock protein 27

Published
2005

29. Vasomotor effects of 5-hydroxytryptamine, histamine, angiotensin II, acetylcholine, noradrenaline, and bradykinin on the cerebral artery of bottlenose dolphin (Tursiops truncatus)

Author

ISLAM, Md. Zahorul, primary, SAWATARI, Yuji, additional, KOJIMA, Shusuke, additional, KIYAMA, Yusuke, additional, NAKAMURA, Moe, additional, SASAKI, Kyouko, additional, OTSUKA, Mika, additional, OBI, Takeshi, additional, SHIRAISHI, Mitsuya, additional, and MIYAMOTO, Atsushi, additional

Published
2020
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31. Cytochrome P450 2JGenes Are Expressed in Dogs, Cats, and Pigs, and Encode Functional Drug-Metabolizing Enzymes

Author

Uno, Yasuhiro, Murayama, Norie, Ijiri, Moe, Kawaguchi, Hiroaki, Yamato, Osamu, Shiraishi, Mitsuya, Asano, Atsushi, Teraoka, Hiroki, Mizukawa, Hazuki, Nakayama, Shouta M.M., Ikenaka, Yoshinori, Ishizuka, Mayumi, and Yamazaki, Hiroshi

Abstract

Cytochrome P450s (P450s) have been identified and analyzed in dogs and pigs, species that are often used in preclinical drug studies. Moreover, P450s are clinically important for drug therapy not only in humans, but also in species under veterinary care, including dogs and cats. In the present study, seven P450s homologous to human CYP2J2, namely, dog CYP2J2; cat CYP2J2; and pig CYP2J33, CYP2J35, CYP2J91, and CYP2J93, were newly identified and characterized, along with pig CYP2J34 previously identified. The cDNAs of these CYP2Js contain open reading frames of 502 amino acids, except for CYP2J35 (498 amino acids), and share high sequence identity (77%–80%) with human CYP2J2. Phylogenetic analysis revealed that dog and cat CYP2J2 were closely related, whereas pig CYP2Js formed a cluster. All seven CYP2Jgenes contain nine coding exons and are located in corresponding genomic regions, with the pig CYP2Jgenes forming a gene cluster. These CYP2J2 mRNAs were predominantly expressed in the small intestine with additional expression in the kidney and brain for dog CYP2J2 and pig CYP2J91 mRNAs, respectively. All seven CYP2Js metabolized human CYP2J2 substrates terfenadine, ebastine, and astemizole, indicating that they are functional enzymes. Dog CYP2J2 and pig CYP2J34 and CYP2J35 efficiently catalyzed ebastine primary hydroxylation and secondary carebastine formation at low substrate concentrations, just as human CYP2J2 does. Velocity-versus-substate plots exhibited sigmoidal relationships for dog CYP2J2, cat CYP2J2, and pig CYP2J33, indicating allosteric interactions. These results suggest that dog, cat, and pig CYP2Js have similar functional characteristics to human CYP2J2, with slight differences in ebastine and astemizole oxidations.SIGNIFICANCE STATEMENTDog CYP2J2; cat CYP2J2; and pig CYP2J33, CYP2J34, CYP2J35, CYP2J91, and CYP2J93, homologous to human CYP2J2, were identified and characterized by sequence, phylogenetic, and genomic structure analyses. Intestinal expression patterns of CYP2J mRNAs were characteristic in dogs, cats, and pigs. Dog, cat, and pig CYP2Js likely play roles as drug-metabolizing enzymes in the small intestine, similar to human CYP2J2.

Published
2022
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33. Pharmacological characteristics of Artemisia vulgaris L. in isolated porcine basilar artery

Author

Nguyen, Ha Thi Thanh, primary, Nguyen, Hai Thanh, additional, Islam, Md. Zahorul, additional, Obi, Takeshi, additional, Pothinuch, Pitchaya, additional, Zar, Phyu Phyu Khine, additional, Hou, De Xing, additional, Van Nguyen, Thanh, additional, Nguyen, Tuong Manh, additional, Van Dao, Cuong, additional, Shiraishi, Mitsuya, additional, and Miyamoto, Atsushi, additional

Published
2016
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35. Antagonistic Effects ofGingko bilobaandSophora japonicaon Cerebral Vasoconstriction in Response to Histamine, 5-Hydroxytryptamine, U46619 and Bradykinin

Author

Nguyen, Ha Thi Thanh, primary, Nguyen, Hai Thanh, additional, Islam, Md. Zahorul, additional, Obi, Takeshi, additional, Pothinuch, Pitchaya, additional, Nguyen, Thanh Van, additional, Nguyen, Tuong Manh, additional, Dao, Cuong Van, additional, Shiraishi, Mitsuya, additional, and Miyamoto, Atsushi, additional

Published
2016
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38. Antagonistic Effects of Gingko biloba and Sophora japonica on Cerebral Vasoconstriction in Response to Histamine, 5-Hydroxytryptamine, U46619 and Bradykinin.

Author

Nguyen, Ha Thi Thanh, Nguyen, Hai Thanh, Islam, Md. Zahorul, Obi, Takeshi, Pothinuch, Pitchaya, Nguyen, Thanh Van, Nguyen, Tuong Manh, Dao, Cuong Van, Shiraishi, Mitsuya, and Miyamoto, Atsushi

Subjects
ANALYSIS of variance, ANIMAL experimentation, CEREBRAL vasospasm, GINKGO, HISTAMINE, PROBABILITY theory, PROSTAGLANDINS, STATISTICS, SWINE, T-test (Statistics), PLANT extracts, DATA analysis, VASOCONSTRICTION, TREATMENT effectiveness
Abstract

The aim of this study was to evaluate, for the first time, the antagonistic effects of Gingko biloba leaf (GB) and Sophora japonica L. flower bud (SJ) extracts on cerebral vasoconstriction in response to KCl, extracellular Ca, histamine, 5-hydroxytryptamine (5-HT), 9,11-dideoxy-9,11-methanoepoxy prostaglandin (PG) F(U46619) and bradykinin (BK), in order to explain their traditional application for diseases associated with cerebral vasospasm. Isolated porcine basilar arteries (PBA) and endothelial cells from them were used as the study materials. Neither SJ nor GB had any effect on the contractions induced by KCl and extracellular Ca. SJ significantly inhibited the contraction induced by histamine, 5-HT, U46619 and BK, whereas GB inhibited histamine-induced contraction, but had no effects on the contractions induced by 5-HT, U46619 and BK. In the presence of diphenhydramine (a H1 receptor antagonist), ketanserin (a 5-HT2 receptor antagonist) and ONO-3708 (a thromboxane (TX) A2/PG receptor antagonist), the inhibitory effects of these extracts on the contractions induced by histamine, 5-HT and U46619 were abolished. SJ significantly inhibited the contractions induced by BK and PGF, but in the presence of ONO-3708 (10 M) had no effect on them. BK enhanced the production of PGF from cultured PBA endothelium cells, and SJ significantly attenuated this enhancement. These results suggest that SJ and GB have a H1-antagonistic effect, and that SJ also attenuates cerebral vasoconstriction mediated via 5-HT2 and TXA2/PG receptors. These findings appear to explain why SJ has been used traditionally as a therapeutic medication for cerebral vasospasm after cerebral hemorrhage. [ABSTRACT FROM AUTHOR]

Published
2016
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42. Data on Wistar Hannover Rats from a General Toxicity Study

Author

Yamatoya, Hideyuki, primary, Kawaguchi, Hiroaki, additional, Yajima, Kanako, additional, Kadokura, Hidetomi, additional, Yoshikawa, Tsuyoshi, additional, Yamashita, Rie, additional, Shiraishi, Mitsuya, additional, Miyamoto, Atsushi, additional, and Miyoshi, Noriaki, additional

Published
2012
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43. Data on Wistar Hannover Rats from an Immunotoxicity Study

Author

Yamatoya, Hideyuki, primary, Kawaguchi, Hiroaki, additional, Fukuda, Takeshi, additional, Kadokura, Hidetomi, additional, Yamashita, Rie, additional, Yoshikawa, Tsuyoshi, additional, Shiraishi, Mitsuya, additional, Miyamoto, Atsushi, additional, and Miyoshi, Noriaki, additional

Published
2012
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