263 research outputs found
SERCA2a過剰発現ラットにおけるイソプロテレノール持続投与誘導肥大心の左室力学的エネルギー学的性質の変化
Overexpression of cardiac sarcoplasmic reticulum Ca2 +-ATPase (SERCA2a) has been suggested as a strategic intervention for cardiac failure. However, its benefit in wild-type (WT) rats with normal SERCA2a levels seems to be small. To investigate whether it would be beneficial in a cardiac failure model with down-regulated SERCA2a levels, we made a cardiac hypertrophy model using isoproterenol infusion (1.2 mg kg− 1 day− 1 for 1 or 4 weeks; TG-ISO1w and TG-ISO4w, respectively) in SERCA2a transgenic (TG) rats and compared these rats with littermate WT rats that underwent the same treatments (WT-ISO1w and WT-ISO4w). We analyzed the left ventricular (LV) mechanoenergetics in the excised heart using our original cross-circulation system. The downward shift of curvilinear LV end-systolic pressure–volume relations (ESPVRs) observed in WT-ISO4w rats was abolished in TG-ISO4w rats. The slope and VO2 intercept of the VO2 (myocardial oxygen consumption per beat)–PVA (systolic pressure–volume area: total mechanical energy per beat) linear relation did not differ in any of the groups. The most important finding was a significantly smaller O2 cost of LV contractility in the TG-ISO4w group, which means that less O2 is needed to exert the same LV contractility, compared with the other groups. The increased ratio of SERCA2a/phospholamban returned to the level of the WT-control group only in the TG-ISO4w group. Longer-term up-regulation of mitochondrial transcription factor A for genes of mitochondrial enzymes producing ATP was observed in TG rats. In conclusion, longer-term overexpression of SERCA2a will be beneficial in the present cardiac failure model with down-regulated SERCA2a levels.博士(医学)・甲619号・平成26年3月17
Amino Amide Organocatalysts for Asymmetric Michael Addition of β-Keto Esters with β-Nitroolefins
Asymmetric Michael addition of β-keto esters with trans-β-nitroolefins using chiral amino amide organocatalyst was tried and afforded synthetically useful chiral Michael adducts in both excellent chemical yields (up to 99%) and stereoselectivities (up to dr. 99:1, up to 98% ee)
新しいカルパイン阻害剤はラット生体位心における緩和な虚血再灌流による左心室機能障害を保護する
We have previously indicated that a new soluble calpain inhibitor, SNJ-1945 (SNJ), attenuates cardiac dysfunction after cardioplegia arrest-reperfusion by inhibiting the proteolysis of α-fodrin in in vitro study. Nevertheless, the in vivo study design is indispensable to explore realistic therapeutic approaches for clinical use. The aim of the present in situ study was to investigate whether SNJ attenuated left ventricular (LV) dysfunction (stunning) after mild ischemic-reperfusion (mI-R) in rat hearts. SNJ (60 μmol/l, 5 ml i.p.) was injected 30 min before gradual and partial coronary occlusion at proximal left anterior descending artery. To investigate LV function, we obtained curvilinear end-systolic pressure–volume relationship by increasing afterload 60 min after reperfusion. In the mI-R group, specific LV functional indices at midrange LV volume (mLVV), end-systolic pressure (ESPmLVV), and pressure–volume area (PVAmLVV: a total mechanical energy per beat, linearly related to oxygen consumption) significantly decreased, but SNJ reversed these decreases to time control level. Furthermore, SNJ prevented the α-fodrin degradation and attenuated degradation of Ca2+ handling proteins after mI-R. Our results indicate that improvements in LV function following mI-R injury are associated with inhibition of the proteolysis of α-fodrin in in situ rat hearts. In conclusion, SNJ should be a promising tool to protect the heart from the stunning.博士(医学)・甲617号・平成26年3月17
Hybrid-Type Squaramide-Fused Amino Alcohol Organocatalysts for Enantioselective Nitro-Aldol Reaction of Nitromethane with Isatins
A series of new hybrid type squaramide-fused amino alcohol (SFAA) catalysts were synthesized and their catalytic efficiency in enantioselective nitro-aldol reaction of various isatins with nitromethane that afford the chiral 3-substituted 3-hydroxyoxindoles in excellent chemical yields (up to 99%) and high enantioselectivities (up to 95% ee) is described. The resulting chiral 3-hydroxyoxindoles could be used as synthetic precursors for the synthesis of several natural products with a broad spectrum of fascinating biological activities
イソプロテレノール誘導肥大心においてNHE-1阻害薬は、ラット左心室の筋スライスのCa2+トランジェントを正常化する
We previously reported that left ventricular (LV) slices from isoproterenol (ISO)-induced hypertrophied rat hearts showed an increase of energy expenditure due to remodeling of Ca2+ handling in excitation–contraction coupling, i.e., suppressed SERCA2a activity and enhanced Na+/Ca2+exchanger-1 (NCX-1) activity. Na+/H+ exchanger-1 (NHE-1) inhibitor (NHEI) has been demonstrated to exert beneficial effects in the development of cardiac remodeling. We hypothesized that a novel NHE-1 selective inhibitor, BIIB723 prevents remodeling of Ca2+ handling in LV slices of ISO-induced hypertrophied rat hearts mediated by inhibiting NCX-1 activity. The significant shortening in duration of multi-cellular Ca2+ transient in ISO group was normalized in ISO + BIIB723 group. The significant increase in amplitude of multi-cellular Ca2+ waves (CaW) generated at high [Ca2+]o of LV slices in ISO group was also normalized in ISO + BIIB723 group. However, the enhanced NCX-1 activity was not antagonized by BIIB723. We recently reported that ISO-induced down-regulation of a Ca2+ handling protein, SERCA2a, was normalized by BIIB723. Therefore, it seems likely that BIIB723 normalized shortened multi-cellular Ca2+ transient duration and increased CaW amplitude in LV slices mediated via normalization of SERCA2a activity. Furthermore, the results presented here suggest the multi-cellular Ca2+ transient duration and CaW amplitude in LV slices might be better indices reflecting SERCA2a activity than SERCA2a protein expression level.博士(医学)・甲618号・平成26年3月17
Chiral primary amino alcohol organobase catalyst for the asymmetric Diels-Alder reaction of anthrones with maleimides
Simple chiral TES-amino alcohol organocatalysts containing a bulkysilyl [triethylsilyl: TES] group on oxygen atom at γ-position were designed andsynthesized as new organocatalysts for the enantioselective Diels-Alder (DA) reactionof anthrones with maleimides to produce chiral hydroanthracene DA adducts (up to99% yield with up to 94% ee)
Efficacy of Brazilian Propolis against Herpes Simplex Virus Type 1 Infection in Mice and Their Modes of Antiherpetic Efficacies
Ethanol extracts (AF-06, 07, and 08, 10 mg/kg) of Brazilian propolis were administered orally to cutaneously herpes simplex virus type 1 (HSV-1)-infected mice three times daily on days 0 to 6 after infection to evaluate their efficacies against HSV-1 infection and significantly limited development of herpetic skin lesions. AF-07 and 08 significantly reduced virus titers in brain and/or skin on day 4 without toxicity, but AF-08 had no anti-HSV-1 activity in vitro. AF-06 and 08 significantly enhanced delayed-type hypersensitivity (DTH) to inactivated HSV-1 antigen in infected mice. Oral AF-08-administration significantly augmented interferon (IFN)-γ production by HSV-1 antigen from splenocytes of HSV-1-infected mice, while direct exposure of splenocytes of infected mice to AF-06 significantly elevated IFN-γ production in vitro. Thus, AF-08 might have components that are active in vivo even after oral administration and those of AF-06 might be active only in vitro. Because DTH is a major host defense for intradermal HSV-1 infection, augmentation of DTH response by AF-06 or 08, directly or indirectly, respectively, may contribute to their efficacies against HSV-1 infection. In addition, AF-06 and 07 possibly contain anti-HSV-1 components contributing to their efficacies. Such biological activities of Brazilian propolis may be useful to analyze its pharmacological actions
Lipase-catalyzed domino Michael-aldol reaction of 2-methyl-1,3-cycloalkanedione and methyl vinyl ketone for the synthesis of bicyclic compounds
Synthesis of bicyclic compounds was achieved via a lipase-catalyzed, stereoselective, domino Michael–aldol reaction of 2-methyl-1,3-cycloalkanedione and methyl vinyl ketone. Appropriate reaction conditions, including the type of enzyme, solvent, and temperature, were determined. In addition, the effects of solvent polarity and addtives were investigated. The reaction proceeded in the presence of lipase AS in a solution of 20% acetone in dimethylsulfoxide (DMSO) at 10 °C for 8 days, followed by the addition of p-toluenesulfonic acid (TsOH) to afford bicyclic compounds in 51–83% yields with moderate stereoselectivity. Although this domino Michael–aldol reaction showed only moderate stereoselectivity, even with the acid-supported enhancement of the reaction, these results represent potential new applications for lipase
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