• 대한약리학회지
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• 제10권1호
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• pp.55-59
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• 1974

Further elucidation of the mechanism of halothane's negative inotropic action has resulted from a study of the effect of various substrates on halothane-depressed rat atria. Approximately 6 mg% halothane was required to maintain a 50% depression of the contractility of rat atria suspended in a modified Krebs-Ringer bicarbonate glucose medium, pH 7.4, $30^{\circ}C$ for 2hr. Both lactate and acetate were found to restore partially the contractility of halothane-depressed atria. The maximally effective concentration of lactate was 5 mM; for acetate it was 2.5mM. Neither 5 nor 20 mM of additional glucose was effective in restoring the force of contraction of halothane-depressed atria. The results are consistent with the hypothesis that halothane exerts at least a part of its negative inotropic effect on rat atria by inhibiting either the uptake or utilization of glucose by the myocardium. The site of blockade must be prior to the conversion of pyruvate to acetyl CoA. In our previous report dealing with the mechanism of cardiac depressant action of inhalation anesthetic halothane, it has been demonstrated that: 1) approximately 6 mg/100 ml halothane is required to maintain 50% depression of the force of contraction of isolated rat atria in Krebs-Ringer bicarbonate glucose medium; 2) pyruvate partially restores the contractility of halothane-depressed atria, but has no effect on normal atria; the partial recovery of depressed atria by the addition of sodium pyruvate is due to the effect of the pyruvate ion itself, not to the sodium ion; 4) addition of pyruvate, to atria depressed with hypertonic medium, produced only further depression. From these findings we concluded that the cardiac depressant action of halothane on rat atria is a manifestation of inhibition of glucose uptake or utilization. The present studies were undertaken to observe the effect of other substrates on halothane-depressed atria in order to substantiate our conclusion. As with the case of pyruvate, lactate and acetate also partially restored the force of contraction of halothane-depressed atria. These data are consistent with the hypothesis that halothane inhibits glucose uptake or utilization in the glycolytic cycle of the myocardium.

• Investigative Magnetic Resonance Imaging
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• 제21권1호
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• pp.1-8
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• 2017

Purpose: To investigate the exchange and redistribution of hyperpolarized $^{13}C$ metabolites between different pools by temporally analyzing the relative fraction of dual $T_2{^*}$ components of hyperpolarized $^{13}C$ metabolites. Materials and Methods: A dual exponential decay analysis of $T_2{^*}$ is performed for [1-$^{13}C$] pyruvate and [1-$^{13}C$] lactate using nonspatially resolved dynamic $^{13}C$ MR spectroscopy from mice brains with tumors (n = 3) and without (n = 4) tumors. The values of shorter and longer $T_2{^*}$ components are explored when fitted from averaged spectrum and temporal variations of their fractions. Results: The $T_2{^*}$ values were not significantly different between the tumor and control groups, but the fraction of longer $T_2{^*}$ [1-$^{13}C$] lactate components was more than 10% in the tumor group over that of the controls (P < 0.1). The fraction of shorter $T_2{^*}$ components of [1-$^{13}C$] pyruvate showed an increasing tendency while that of the [1-$^{13}C$] lactate was decreasing over time. The slopes of the changing fraction were steeper for the tumor group than the controls, especially for lactate (P < 0.01). In both pyruvate and lactate, the fraction of the shorter $T_2{^*}$ component was always greater than the longer $T_2{^*}$ component over time. Conclusion: The exchange and redistribution of pyruvate and lactate between different pools was investigated by dual component analysis of the free induction decay signal from hyperpolarized $^{13}C$ experiments. Tumor and control groups showed differences in their fractions rather than the values of longer and shorter $T_2{^*}$ components. Fraction changing dynamics may provide an aspect for extravasation and membrane transport of pyruvate and lactate, and will be useful to determine the appropriate time window for acquisition of hyperpolarized $^{13}C$ images.

• Clinical and Experimental Reproductive Medicine
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• 제23권3호
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• pp.333-339
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• 1996

난구세포는 lactate와 pyruvate를 쉽게 생성하고, 이로 인해 배양액내 에너지원의 농도를 변화시켜 난자의 수정과 배양에 영향을 주는 것으로 알려져 있다. Glucose, lactate 및 pyruvate의 농도가 상이한 M16, MTF 및 CZB배양액에서 난구세포를 포함한 생쥐난자의 체외 수정과 발달을 관찰하여, 이들 기질의 영향에 대하여 살펴보고 배양액의 유용성을 재검토하고자 하였다. Glucose를 제거한 배양액 (CZ2 배양액)에서 수정율과 배반포 형성율은 다른 배양액에 비해 유의하게 감소되었으나 (p<0.05), 생쥐 난관액과 동일한 기질 농도로 조성된 MTl (난간액이 난구세포를 포함하고 있을 때) 및 MT2배양액 (난관액이 난구세포를 포함하고 있지 않을 때)과 glucose를 포함한 modified CZB배양액에서는 영향이 없었다. 이와 같은 결과로 기질의 농도를 생리적 수준으로 조정한 배양액의 이용은 난구세포를 포함한 생쥐 난자의 체외수정과 그 발달을 향상시키지 못하고, glucose의 제거는 악영향을 나타내는 것으로 사료된다.

• Clinical and Experimental Reproductive Medicine
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• 제27권1호
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• pp.1-7
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• 2000

Objective: Mammalian embryos undergo changes of energy environment for transfer from oviduct to uterus. Also, the human reproductive organ (oviduct, uterus) contains energy sources of different concentration (oviduct - glucose: 0.5 mM, pyruvate: 0.32 mM, lactate: 10.5 mM; uterus - goucose: 3.15 mM, pyruvate: 0.1mM, lactate: 5.87 mM, respectively). This study was conducted to examine the effect of these energy sources added in DMEM with glutamine on the mouse embryo development. Methods: There was used ICR female mouse. Two cell embryos of mouse are collected by method of 'flushing'. Flushing fluid was used Ham's F-10 added to 20% FBS. The collected 2 cell embryos were cultured in media such as Control (only DMEM), group A and B (DMEM supplemented with 0.5 mM and 3.15 mM glucose), and group C and D (DMEM supplemented with 0.1 mM and 0.32 mM pyruvate), and group E and F (DMEM supplemented with 5.87 mM and 10.5 mM lactate). All experimental media supplemented with 20% hFF, respectively. Pattern of embryo development was observed to interval at 24hr during 96hr. Results : The media with glutamine added glucose (group A: 51.0%; group B: 48.4%) was significantly (p<0.05) higher than other experimental group in development into the morula stage after 24 hr in culture, but not significantly different compared with control and the rate of development into the blastocyst was significantly (p<0.05) low in the both of pyruvate (group C: 7.9% group D: 6.8%) and lactate (group E: 7.1%, group F: 7.1%) treatment group after 48 hr in culture. Development into the blastocyst and hatched balstocyst after 72 hr in culture revealed similarly in control (81.9%) and glucose treatment group (group A: 83.3%, group B: 82.8%). However, development into the hatched and attached blastocyst after 96hr in culture revealed significantly (p<0.05) development in the glucose treatment group (group A: 82.3%, group B: 78.5%) than control (63.2%), and its of pyruvate (group C: 34.1%, group D: 34.1%) and lactate (group E: 25.9%, group F: 33.3%) treatment group were significantly (p<0.05) lower than control similar to previous observations. Conclusion : The glucose added to the DMEM with only glutamine, as energy source, was highly to the rate of development compared with control, but the other energy sources were not, synthetically. Above refer to, the human reproductive organ (oviduct, uterus) contains energy sources of different concentration. Thus, further studies are will examine continuously to effects by interaction of different energy sources in the mouse embryo development, and these results will provide to foundation on the human embryo culture.

• 한국작물학회:학술대회논문집
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• 한국작물학회 2000년도 춘계 학술대회지
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• pp.330-331
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• 2000

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2000년도 춘계학술발표대회
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• pp.81-84
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• 2000

• Journal of Microbiology and Biotechnology
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• 제11권4호
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• pp.592-597
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• 2001

The pyruvate dehydrogenase complex (PDC) catalyzes the oxidative decarboxylation of pyruvate with the formation of $CO_2$, acetyl-CoA, NADH, and H+. This complex contains multiple copies of three catalytic components including pyruvate dehydrogenase(E1), dihydrolipoamide acetyltransferase(E2), and dihydrolipoamide dehydrogenase (E3). Two regulatory components (E1-kinase and phospho-E1 phosphatase) and functionally less-understood protein (protein X, E3BP) are also involved in the formation of the complex. In this study, cloning and characterization of a gene for human E3BP have been carried out. A cDNA encoding the human E3BP was isolated by database search and cDNA library screening. The primary structure of E3BP has some similar characteristics with that of E2 in the lipoyl domain and the carboxyl-terminal domain, based on the nucleotide sequence and the deduced amino acid sequence. However, the conserved amino acid moiety including the histidine residue for acetyltransferase activity in E2 is not conserved in the case of human E3BP. The human E3BP was expressed and purified in E. coli. The molecular weight of the protein, excluding the mitochondrial target sequence, was about 50 kDa as determined by SDS-PAGE. Cloning of human E3BP and expression of the recombinant E3BP will facilitate the understanding of the role(s) of E3BP in mammalian PDC.

• 한국미생물·생명공학회지
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• 제2권1호
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• pp.45-50
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• 1974

1. L-cysteine을 pyruvate, sulfide 및 ammonia로 분해하는 반응을 촉매하는 효소인 cysteinedesulfhydrase의 촉매기능에 대해 연구해온 바 Aerobacter aerogenes로부터 유도생산한 cysteinedesulfhydrase를 사용하여 분해반응의 역반응에 의해 pyruvate, ammonia 및 sulfide로부터 cysteine의 유도체인 S-methyl-L-cysteine 및 S-ethyl-L-cysteine을 합성하였다. 2. 합성반응에 있어서 S-methyl-L-cysteine 및 S-ethyl-L-cysteine의 생성량은 반응시간과 효소량에 비예적인 관계를 나타내었고 반응의 최적 pH는 10.0이었다. 3. 효소적 합성법에 의해 생산된 S-methyl-L-cysteine 및 S-ethyl-L-cysteine을 반응액으로 부터 단리, 결정화해서 이들 합성산물에 대한 Ion exchange chromatogram, NMR spectrum, element analysis, molecular weight 및 melting point 측정 등의 분석시험을 행한 바 이들 화합물에 대한 이론치와 잘 일치되는 결과를 얻었다.

• 한국응용약물학회:학술대회논문집
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• 한국응용약물학회 1994년도 춘계학술대회 and 제3회 신약개발 연구발표회
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• pp.260-260
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• 1994

Mammalian pyruvate dehydrogenase complex(PDC) enzyme consists of multiple oopies of three major oligomeric enzymes-El, E2 E3. And protein X is one of the enzymatic constituents which is tightly bound to E2 subunit This complex enzyme is responsible for the oxidative decarboxylation of pyruvate producing of acetyl CoA which is a key intermediate for the entry of carbohydrates into the TCA cycle for its complete metabolic conversion to CO$_2$. And the overall activity of the complex enzyme is regulated via covalent nodification of El subunit by a El specific phosphatase ad kinase. Protein X has lipoyl moiety that undergoes reduction and acetylation during ezymatic reaction and has been known h be involved in the binding of E3 subunit to E2 core and in the regulatory activity of kinase. The purification of protein X has not been achieved majorly because of its tight binding to E2 subunit The E2-protein X subcomplex was obtained by the established methods and the detachment of protein X from E2 was accomplished in the 0.1M borate buffer containing 150mM NaCl. During the storage of the subcomplex in frozen state at -70$^{\circ}C$, the E2 subunit was precipitated and the dissociated protein X was obtained by cntrifegation into the supernatant The verification of protein X was accomplished by (1)the migration on SDS-PAGE, (2)acetylation by 〔2$\^$-l4/C〕 pyruvate, and (3)internal amino acid sequence analysis of tryptic digested enzyme.

• Applied Biological Chemistry
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• 제41권4호
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• pp.241-245
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• 1998

Two oxidation states of chromium commonly occur in natural soil/water systems, Cr(III) and Cr(VI). The oxidized form, Cr(VI), exists as the chromate ion and is more mobile and toxic than Cr(III). Therefore oxidation of Cr(III) by various Mn-oxides in natural systems is a very important environmental concern. Organic substances can inhibit the Cr(III) oxidation by binding, Cr(III) strongly and also by dissolving Mn-oxides. Most of Cr(III) oxidation studies were carried out using in vitro systems without organic substances which exist in natural soil/water systems. In this study effect of organic acids - oxalate and pyruvate - on Cr(III) oxidation by $birnessite({\delta}-MnO_2)$ was examined. The two organic acids significantly inhibited Cr(III) oxidation by birnessite. Oxalate showed more significant inhibition than pyruvate. As solution pH was lowered in the range of 3.0 to 5.0, the Cr(III) oxidation was more strongly depressed. Addition of more organic acids reduced the Cr(III) oxidation mare extensively. Different inhibition effects by the organic acids could be due to their ability of reductive dissolution of Mn-oxides and/or Cr(III) binding. Organic acids dissolved Mn-oxide during the Cr(III) oxidation by the oxide, Dissolution by oxalic acid was much greater than that by pyruvate, and the dissolution was more extensive at lower pH. Inhibition of Cr(III) oxidation was parallel to the dissolution of Mn-oxide by organic acids. Although the effect of Cr(III) binding by organic acids on Cr(III) oxidation is not known yet, Mn-oxide dissolution by organic acids could be a main reason for the inhibition of Cr(III) oxidation by Mn-oxide in presence of organic acids. Thus oxidation of Cr(III) to Cr(VI) by various Mn-oxides in natural systems could be much less than the oxidation estimated by in vitro studies with only Cr(III) and Mn-oxides.