• 제목/요약/키워드: intracellular ATP level

검색결과 33건 처리시간 0.03초

황체막에서의 $Ca^{++}-ATPase$의 특성 (Partial Characterization of Physicochemical and Kinetic Properties of $Ca^{++}-ATPase$ System in Luteal Membranes)

  • 최규복;구본숙;김인교
    • The Korean Journal of Physiology
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    • 제20권2호
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    • pp.257-270
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    • 1986
  • It has been reported that the luteal function may be regulated by the intracellular calcium in luteal cells (Higuchi et al, 1976; Dorflinger et at, 1984; Gore and Behrman, 1984) which is adjusted partially by $Ca^{++}-ATPase$ activities in luteal cell membranes (Verma and Pennistion, 1981). However, the physicochemical and kinetic properties of $Ca^{++}-ATPase$ in luteal membranes were not fully characterized. This study was, therefore, undertaken to partially characterize the physicochemical and kinetic properties of $Ca^{++}-ATPase$ system in luteal membranes and microsomal fractions, known as an one of the major $Ca^{++}$ storge sites (Moore and Pastan, 1978), from the highly luteinized ovary Highly luteinized ovaries were obtained from PMSG-hCG injected immautre female rats. Light membrane and heavy membrane fractions and microsomal fractions were prepared by the differential and discontinuous sucrose density gradient centrifugation method desribed by Bramley and Ryan (1980). Light membrane and heavy membrane fractions and microsomal fractions from highly luteinized ovaries are composed of the two different kinds of $Ca^{++}-ATPase$ system. One is the high affinity $Ca^{++}-ATPase$ which is activated in low $Ca^{++}$ concentration (Km, 10-30 nM), the other is low affinity $Ca^{++}-ATPase$ activated in higher $Ca^{++}$ concentration $(K_{1/2},\;40\;{\mu}M)$. At certain $Ca^{++}$ concentrations, activities of high and low affinity $Ca^{++}-ATPase$ are the highest in light membrane fractions and are the lowest in microsomal fractions. It appeares that high affinity $Ca^{++}-ATPase$ system have 2 binding sites for ATP (Hill's coefficient; around 2 in all membrane fractions measured) and the positive cooperativity of ATP bindings obviously existed in each membrane fractions. The optimum pH for high affinity $Ca^{++}-ATPase$ activation is around S in all membrane fractions measured. The lipid phase transition temperature measured by Arrhenius plots of high affinity $Ca^{++}-ATPase$ activity is around $25^{\circ}C$. The activation energies of high affinity $Ca^{++}-ATPase$ below the transition temperature are similar in each membrane fractions, but at the above transition temperature, it is the hightest in heavy membrane fractions and the lowest in microsomal fractions. According to the above results, it is suggested that intracellular $Ca^{++}$ level, which may regulate the luteal function, may be adjusted primarily by the high affinity $Ca^{++}-ATPase$ system activated in intracellular $Ca^{++}$ concentration range $(below\;0.1\;{\mu}M)$.

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콜라겐으로 유도한 사람 혈소판 응집에 미치는 Scopoletin의 억제 효과 (Inhibitory Effects of Scopoletin in Collagen-induced Human Platelet Aggregation)

  • 권혁우;신정해;박창은;이동하
    • 대한임상검사과학회지
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    • 제51권1호
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    • pp.34-41
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    • 2019
  • 혈소판 응집은 혈관 손상의 경우 지혈 플러그 형성에 필수적이다. 그러나, 과도한 혈소판 응집은 혈전증, 죽상 동맥 경화증 및 심근 경색과 같은 순환기 장애를 일으킬 수도 있다. Scopoletin은 Scopolia 또는 Artemisia 속 식물의 뿌리에서 발견되는 성분으로, 항응고 및 항말라리아 작용을 가지는 것으로 알려져 있다. 본 연구는 collagen에 의해 유발된 혈소판 응집에 scopoletin이 미치는 영향을 조사하였다. Scopoletin은 활성화된 혈소판에서 생성되는 응집 유도 분자인 thromboxane $A_2$ ($TXA_2$) 및 세포 내 $Ca^{2+}$ 동원 ($[Ca^{2+}]_i$)의 하향 조절을 통해 항 혈소판 효과를 나타내었다. 한편, scopoletin은 세포 내 $Ca^{2+}$-길항제인 것으로 알려져 있는 cyclic adenosine monophosphate(cAMP)와 cyclic guanosine monophosphate (cGMP) 수치를 증가시켰다. 특히, scopoletin은 cGMP보다 cAMP 수준을 강력하게 증가함으로써 콜라겐에 의해 유발된 사람 혈소판 응집에서의 ${\alpha}IIb/{\beta}_3$에 대한 피브리노겐 결합을 억제하였다. 또한, scopoletin은 용량 의존적으로 collagen에 의해 증가된 adenosine trisphosphate (ATP)의 방출을 억제하였다. 이 결과는 혈소판 내 과립 분비를 통한 응집 증폭작용이 scopoletin에 의해 억제되었음을 의미한다. 따라서, 본 연구는 scopoletin이 강력한 항혈소판 효과를 가지며 혈소판-유래의 혈관 질환을 예방할 가능성이 크다는 것을 입증하였다.

Inhibitory effects of total saponin from Korean red ginseng via vasodilator-stimulated phosphoprotein-Ser157 phosphorylation on thrombin-induced platelet aggregation

  • Lee, Dong-Ha;Cho, Hyun-Jeong;Kim, Hyun-Hong;Rhee, Man Hee;Ryu, Jin-Hyeob;Park, Hwa-Jin
    • Journal of Ginseng Research
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    • 제37권2호
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    • pp.176-186
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    • 2013
  • In this study, we have investigated the effects of total saponin from Korean red ginseng (TSKRG) on thrombin-induced platelet aggregation. TSKRG dose-dependently inhibited thrombin-induced platelet aggregation with $IC_{50}$ value of about 81.1 ${\mu}g/mL$. In addition, TSKRG dose-dependently decreased thrombin-elevated the level of cytosolic-free $Ca^{2+}$ ($[Ca^{2+}]_i$), one of aggregation-inducing molecules. Of two $Ca^{2+}$-antagonistic cyclic nucleotides as aggregation-inhibiting molecules, cyclic adenosine monophosphate (cAMP) and cyclic guanosine monophosphate (cGMP), TSKRG significantly dose-dependently elevated intracellular level of cAMP, but not cGMP. In addition, TSKRG dose-dependently inhibited thrombin-elevated adenosine triphosphate (ATP) release from platelets. These results suggest that the suppression of $[Ca^{2+}]_i$ elevation, and of ATP release by TSKRG are associated with upregulation of cAMP. TSKRG elevated the phosphorylation of vasodilator-stimulated phosphoprotein (VASP)-$Ser^{157}$, a cAMP-dependent protein kinase (A-kinase) substrate, but not the phosphorylation of VASP-$Ser^{239}$, a cGMP-dependent protein kinase substrate, in thrombin-activated platelets. We demonstrate that TSKRG involves in increase of cAMP level and subsequent elevation of VASP-$Ser^{157}$ phosphorylation through A-kinase activation to inhibit $[Ca^{2+}]_i$ mobilization and ATP release in thrombin-induced platelet aggregation. These results strongly indicate that TSKRG is a beneficial herbal substance elevating cAMP level in thrombin-platelet interaction, which may result in preventing of platelet aggregation-mediated thrombotic diseases.

Modulation of $Ca^{2+}-Activated$ Potassium Channels by cGMP-Dependent Signal Transduction Mechanism in Cerebral Arterial Smooth Muscle Cell of the Rabbit

  • Han, Jin;Kim, Na-Ri;Lee, Kwang-Bok;Kim, Eui-Yong
    • The Korean Journal of Physiology and Pharmacology
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    • 제4권6호
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    • pp.445-453
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    • 2000
  • The present investigation tested the hypothesis that the activation of protein kinase G (PKG) leads to a phosphorylation of $Ca^{2+}-activated$ potassium channel $(K_{Ca}\;channel)$ and is involved in the activation of $K_{Ca}$ channel activity in cerebral arterial smooth muscle cells of the rabbit. Single-channel currents were recorded in cell-attached and inside-out patch configurations of patch-clamp techniques. Both molsidomine derivative 3-morpholinosydnonimine-N-ethylcarbamide $(SIN-1,\;50\;{\mu}M)$ and 8-(4-Chlorophenylthio)-guanosine-3',5'-cyclic monophosphate $(8-pCPT-cGMP,\;100\;{\mu}M),$ a membrane-permeable analogue of cGMP, increased the $K_{Ca}$ channel activity in the cell-attached patch configuration, and the effect was removed upon washout of the drugs. In inside-out patches, single-channel current amplitude was not changed by SIN-1 and 8-pCPT-cGMP. Application of ATP $(100\;{\mu}M),$ cGMP $(100\;{\mu}M),$ ATP+cGMP $(100\;{\mu}M\;each),$ PKG $(5\;U/{\mu}l),$ ATP $(100\;{\mu}M)+PKG\;(5\;U/{\mu}l),$ or cGMP $(100\;{\mu}M)+PKG\;(5\;U/{\mu}l)$ did not increase the channel activity. ATP $(100\;{\mu}M)+cGMP\;(100\;{\mu}M)+PKG\;(5\;U/{\mu}l)$ added directly to the intracellular phase of inside-out patches increased the channel activity with no changes in the conductance. The heat-inactivated PKG had no effect on the channel activity, and the effect of PKG was inhibited by 8-(4-Chlorophenylthio)-guanosine-3',5'-cyclic monophosphate, Rp-isomer $(Rp-pCPT-cGMP,\;100\;{\mu}M),$ a potent inhibitor of PKG or protein phosphatase 2A (PP2A, 1 U/ml). In the presence of okadaic acid (OA, 5 nM), PP2A had no effect on the channel activity. The $K_{Ca}$ channel activity spontaneously decayed to the control level upon washout of ATP, cGMP and PKG, and this was prevented by OA (5 nM) in the medium. These results suggest that the PKG-mediated phosphorylations of $K_{Ca}$ channels, or some associated proteins in the membrane patch increase the activity of the $K_{Ca}$ channel, and the activation may be associated with the vasodilating action.

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Assessment of cryopreserved sperm functions of Korean native brindled cattle (Chikso) from different region research centers of Korea

  • Ma, Lei;Jung, Dae-Jin;Jung, Eun-Ju;Lee, Woo-Jin;Hwang, Ju-Mi;Bae, Jeong-Won;Kim, Dae-Hyun;Yi, Jun Koo;Lee, Sang Moo;Ha, Jae Jung;Kwon, Woo-Sung
    • 한국동물생명공학회지
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    • 제36권2호
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    • pp.106-115
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    • 2021
  • Sperm cryopreservation is an important method of assisted reproductive techniques and storing genetic resources. It plays a vital role in genetic improvement, livestock industrial preservation of endangered species, and clinical practice. Consequently, the cryopreservation technique is well organized through various studies, especially on Korean native cattle (Hanwoo). However, the cryopreservation technique of Korean native brindled cattle, which is one of the native cattle species in Korea, is not well organized. Therefore, it is necessary to develop a Supplementary Table technique for the cryopreservation of Korean native brindled cattle. For this purpose, it is important to first evaluate the quality of the currently produced cryopreserved sperm of Korean native brindled cattle. In this study, we randomly selected 72 individual Korean native brindled cattle semen samples collected from 8 different region research centers and used them to evaluate sperm functions. We focused on the quality evaluation of cryopreserved Korean native brindled cattle semen following the measurement of motion kinematics, capacitation status, intracellular ATP level, sperm motility, and cell viability. Then, the values of each of the eight groups were derived from various sperm parameters of nine individual samples, including sperm motility, kinematics, cellular motility, and intracellular ATP levels, which were used to compare and evaluate sperm function. Overall, differences in various sperm parameters were observed between most of the research centers. Particularly, the deviations of motility and motion kinematics were high according to the sample. Therefore, we suggest that it is necessary to develop a standard method for the cryopreservation of Korean native brindled cattle semen. We also suggest the need for sperm quality evaluation of the cryopreserved semen of Korean native brindled cattle before using artificial insemination to attain a high fertility rate.

Aspartate-glutamate carrier 2 (citrin): a role in glucose and amino acid metabolism in the liver

  • Milan Holecek
    • BMB Reports
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    • 제56권7호
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    • pp.385-391
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    • 2023
  • Aspartate-glutamate carrier 2 (AGC2, citrin) is a mitochondrial carrier expressed in the liver that transports aspartate from mitochondria into the cytosol in exchange for glutamate. The AGC2 is the main component of the malate-aspartate shuttle (MAS) that ensures indirect transport of NADH produced in the cytosol during glycolysis, lactate oxidation to pyruvate, and ethanol oxidation to acetaldehyde into mitochondria. Through MAS, AGC2 is necessary to maintain intracellular redox balance, mitochondrial respiration, and ATP synthesis. Through elevated cytosolic Ca2+ level, the AGC2 is stimulated by catecholamines and glucagon during starvation, exercise, and muscle wasting disorders. In these conditions, AGC2 increases aspartate input to the urea cycle, where aspartate is a source of one of two nitrogen atoms in the urea molecule (the other is ammonia), and a substrate for the synthesis of fumarate that is gradually converted to oxaloacetate, the starting substrate for gluconeogenesis. Furthermore, aspartate is a substrate for the synthesis of asparagine, nucleotides, and proteins. It is concluded that AGC2 plays a fundamental role in the compartmentalization of aspartate and glutamate metabolism and linkage of the reactions of MAS, glycolysis, gluconeogenesis, amino acid catabolism, urea cycle, protein synthesis, and cell proliferation. Targeting of AGC genes may represent a new therapeutic strategy to fight cancer.

라이코펜이 사이토카인에 의해 유도된 베타세포 사멸에 미치는 효과 및 기전 연구 (Protective effect of lycopene against cytokine-induced β-cell apoptosis in INS-1 cells)

  • 김경;장세은;배공득;전희숙;오윤신
    • Journal of Nutrition and Health
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    • 제51권6호
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    • pp.498-506
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    • 2018
  • 본 연구는 베타세포에서 라이코펜의 항사멸 효과와 그 기전에 대해 조사하기 위해 실시하였다. 라이코펜에 의한 베타세포독성을 조사하기 위해 다양한 농도 (0.1, 1, 10 nM)로 처리하였을 경우, 저농도에서 세포독성이 나타나지 않음을 관찰하였다. 선택한 농도를 사이토카인 혼합물과 함께 처리하였을 경우, 세포 생존율이 증가하는 것을 관찰하였고, 세포사멸 유도 단백질인 Bax의 발현양은 감소하고, 세포사멸억제 단백질인 Bcl-2 발현양은 증가하는 것을 관찰하였다. 또한 사이토카인 혼합물에서 증가하였던 세포내 산화스트레스가 라이코펜과 함께 처리하였을 경우 감소되는 것을 관찰하였고 이러한 효과는 항산화 유전자인 GCLC, NQO1, HO-1의 발현양이 증가함으로서 일어난 현상임을 알 수 있었다. 라이코펜은 미토콘드리아의 생성 및 기능과 관련된 유전자의 발현을 증가시키고 사이토카인 혼합물에 의해 감소되었던 세포내 ATP 생성량을 증가시켰다. 이러한 결과는 라이코펜의 항산화효과와 미토콘드리아 기능 개선 효과가 사이토카인에 의한 베타세포 사멸을 억제하는 기전 중의 하나로 작용할 수 있음을 의미한다. 향후 라이코펜이 베타세포를 타겟으로 하는 제 2형 당뇨 치료의 기능성 소재로 개발될 가능성이 있음을 시사하는 바이다.

바이러스성 출혈성 패혈증 바이러스 NV 단백질에 의한 glucokinase 전사 활성의 억제 (Viral Hemorrhagic Septicemia Virus NV Gene Decreases Glycolytic Enzyme Gene Transcription)

  • 조미영;황지연;지보영;박명애;성미소;김소영;정예은;정재훈;최영현
    • 생명과학회지
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    • 제26권12호
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    • pp.1470-1476
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    • 2016
  • 바이러스성 출혈성 패혈증 바이러스(VHSV)는 넙치를 포함한 어류 양식의 막대한 피해를 일으키는 바이러스 병원체이며, VHSV가 생성하는 6개의 바이러스 단백질들 중에서 NV 단백질이 병원성에 관여하는 것으로 알려져 있다. VHSV-감염 넙치를 이용한 전사체 마이크로 어레이의 선행 분석 결과에 의하면 VHSV 감염이 해당과정 효소들의 mRNA 발현을 억제함으로써 넙치 세포에서 ATP 생성을 감소시켰음을 알 수 있었다. 이들 결과를 토대로, 본 연구에서는 VHSV NV 단백질이 해당과정 효소인 glucokinase의 발현에 미치는 영향을 검토하였다. 본 연구의 결과에 의하면, NV 단백질은 넙치 세포에서 glucokinase의 mRNA 발현을 감소시켰으며, 새롭게 동정한 glucokinase의 유전자 프로모터의 활성 실험결과, NV 단백질이 glucokinase의 프로모터 활성을 저해함을 알 수 있었다. 이와 같은 작용 결과들로 인하여 VHSV NV 단백질의 발현이 세포 내로의 포도당 흡수 또한 감소시켰다. 이러한 결과들은 VHSV NV 단백질이 유전자 발현의 전사 수준에서 음성적으로 해당과정의 효소 발현을 조절함을 의미하며, 결국 세포 내 에너지의 결핍으로 넙치의 폐사로 이어질 가능성을 보여주는 것이다.

관중(Dryopteris crassirhizoma Nakai)의 식중독 미생물 증식 억제 물질의 분리 및 항균작용 (Isolation and Antimicrobial Action of Growth Inhibitory Substance on Food-borne Microorganisms from Dryopteris crassirhizoma Nakai)

  • 한지숙;이지영;백남인;신동화
    • 한국식품과학회지
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    • 제33권5호
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    • pp.611-618
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    • 2001
  • 관중 에탄올 추출물의 Listeria monocytogenes 5 균주에 대한 최소증식저해농도(MIC)는 $100ppm{\sim}500ppm$이었고, 헥산 분획물의 경우 MIC는 50ppm 이하이었다. 헥산 분획물의 항균 활성물질을 분리, 정제하여 얻은 D8-2-5 획분의 경우는 MIC가 20ppm이었다. 항균활성이 인정된 D8-2-5 획분의 살균 효과를 알아보기 위해 생균수를 측정한 결과 초기 접종균수보다 $4{\sim}6$ log cycle 정도 감소하여 살균효과가 입증되었다. 또한 D8-2-5 획분을 처리한 균체와 처리하지 않은 균체를 투과 전자현미경으로 관찰했을 때 D8-2-5 획분을 처리하지 않은 균체 세포벽의 비정상적인 형태를 관찰할 수 있었다. 또한 관중 헥산 분획물의 항균 spectrum을 관찰한 결과 Vibrio parahaemolyticus와 Bacillus cereus에 대하여 50ppm 첨가 수준에서 균증식을 완전히 억제시켰으며, Staphylococcus aureus의 경우 25ppm 첨가시에도 균증식이 완전히 억제되었다.

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Identification of AMPK activator from twelve pure compounds isolated from Aralia Taibaiensis: implication in antihyperglycemic and hypolipidemic activities

  • Li, Yuwen;Park, Jongsun;Wu, Yin;Cui, Jia;Jia, Na;Xi, Miaomiao;Wen, Aidong
    • The Korean Journal of Physiology and Pharmacology
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    • 제21권3호
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    • pp.279-286
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    • 2017
  • The root bark extract of Aralia taibaiensis is used traditionally for the treatment of diabetes mellitus in China. The total saponin extracted from Aralia Taibaiensis (sAT) has effective combined antihyperglycemic and hypolipidemic activities in experimental type 2 diabetic rats. However, the active compounds have not yet been fully investigated. In the present study, we examined effects of twelve triterpenoid saponins on AMP-activated protein kinase (AMPK) activation, and found that compound 28-O-${\beta}$-D-glucopyranosyl ester (AT12) significantly increased phosphorylation of AMPK and Acetyl-CoA carboxylase (ACC). AT12 effectively decreased blood glucose, triglyceride (TG), free fatty acid (FFA) and low density lipoprotein-cholesterol (LDL-C) levels in the rat model of type 2 diabetes mellitus (T2DM). The mechanism by which AT12 activated AMPK was subsequently investigated. Intracellular ATP level and oxygen consumption were significantly reduced by AT12 treatment. The findings suggested AT12 was a novel AMPK activator, and could be useful for the treatment of metabolic diseases.