共查询到20条相似文献,搜索用时 31 毫秒
1.
Spacek T Santorová J Zacharovová K Berková Z Hlavatá L Saudek F Jezek P 《The international journal of biochemistry & cell biology》2008,40(8):1522-1535
Increased ATP/ADP ratio resulting from enhanced glycolysis and oxidative phosphorylation represents a plausible mechanism controlling the glucose-stimulated insulin secretion (GSIS) in pancreatic β-cells. Although specific bioenergetics might be involved, parallel studies of cell respiration and mitochondrial membrane potential (ΔΨm) during GSIS are lacking. Using high resolution respirometry and parallel ΔΨm monitoring by two distinct fluorescence probes we have quantified bioenergetics in rat insulinoma INS-1E cells representing a suitable model to study in vitro insulin secretion. Upon glucose addition to glucose-depleted cells we demonstrated a simultaneous increase in respiration and ΔΨm during GSIS and showed that the endogenous state 3/state 4 respiratory ratio hyperbolically increased with glucose, approaching the maximum oxidative phosphorylation rate at maximum GSIS. Attempting to assess the basis of the “toxic” effect of fatty acids on insulin secretion, GSIS was studied after linoleic acid addition, which diminished respiration increase, ΔΨm jump, and magnitude of insulin release, and reduced state 3/state 4 dependencies on glucose. Its effects were due to protonophoric function, i.e. uncoupling, since without glucose, linoleic acid accelerated both state 3 and state 4 respiration by similar extent. In turn, state 3 respiration increased marginally with linoleic acid at 10–20 mM glucose. We conclude that upon glucose addition in physiological range, the INS-1E cells are able to regulate the oxidative phosphorylation rate from nearly zero to maximum and that the impairment of GSIS by linoleic acid is caused by mitochondrial uncoupling. These findings may be relevant to the pathogenesis of type 2 diabetes. 相似文献
2.
Esther Van Praag 《International journal of biological macromolecules》1997,21(4):307-317
The glycolytic reaction of grapefruit PPi-dependent phosphofructokinase (PFP) depends on the presence of Fru-2,6-P2 (Ka=6.7 nM). This molecule was further demonstrated in grapefruit juice sac cells. Citrate, -ketoglutarate and isocitrate competitively inhibited the binding of Fru-2,6-P2 to PFP. The affinity for Fru-6-P (Km=159 μM) and PPi (Km=33 μM) were not affected by the addition of these molecules. In the gluconeogenic reaction, the presence of Fru-2,6-P2 did not affect the Km of Fru-1,6-P2 (61 μM) in contrast to orange fruit PFP. These results led to the building of a computer model of PFP, based on the known structure of Bacillus stearothermophilus ATP-dependent phosphofructokinase (ATP-PFK). The results show that catalysis of Fru-6-P in the chain is most unlikely, due to amino-acid substitutions and that Fru-2,6-P2 can bind between the and β subunits. 相似文献
3.
Kelvin Tsai Tai-Ger Hsu Fung-Jou Lu Chen-Fu Hsu Tsung-Yun Liu Chi-Woon Kong 《Free radical research》2001,35(4):395-403
Aging is associated with impaired immunity and reduced host defenses. Mitochondrial bioenergetic dysfunctions and reduced antioxidative ability of immunocompetent cells may contribute to this phenomenon. In this study, 60 healthy volunteers of different age groups donated their blood after overnight fasting. Leukocytes were subjected to oxidative injuries by exposure to t-butylhydroperoxide, and were labeled with fluorochromes for measuring mitochondria transmembrane potential (Δωm), membrane peroxidation and mitochondrial oxidant formation. Δωm declined after t-butylhydroperoxide exposure, and the change was more prominent in leukocytes from older individuals. Cyclosporin A partly restored Δωm, implying the contributing role of mitochondrial permeability transition pores. The mitochondrial depolarization was accompanied by increased oxidant formation and oxidation of pyridine nucleotides, which were more prominent in older subjects. The results support the view that the bioenergetic functions of mitochondria are more susceptible to oxidative injury in aged individuals. The decreased ability of leukocytes to resist oxidative stress may contribute to immunosenescence in humans. 相似文献
4.
A general 3-D dynamic model for men's and women's discus flight is presented including precession of spin angular momentum induced by aerodynamic pitching moment. Dependence of pitching moment coefficient on angle of attack is estimated from experiment. Numerical integration of 11 equations of motion for nominal release speed v0=25 m/s and axial spin p0=42 rad/s also requires 3 other release conditions; initial discus flight path angle β0, pitch attitude θ0, and roll angle φ0. Optimal values for these release conditions are calculated iteratively to maximize range and are similar for both men and women. The optimal men's trajectory and range R=69.39 m is produced by the strategy β0=38.4°, θ0=30.7°, and φ0=54.4°. Initial angular velocities except spin are chosen to minimize wobble but an optimal initial spin rate p0=25.2 rad/s exists that also maximizes range. Optimal 3-D range exceeds that predicted by 2-D models because, although angle of attack and lift are negative initially, 3-D motion allows advantageous orientation of lift later in flight, with tilt of the axis of symmetry from vertical becoming much smaller at landing. Optimal strategies are discontinuous with wind speed, resulting in slicing and kiting strategies in large head and tail winds, respectively. Sensitivity of optimal range is largest to initial β0 and least to φ0. Present calculations do not account for dependence of initial release angle or spin on release velocity or among other release conditions. 相似文献
5.
为了探明典型荒漠灌木优势物种黑沙蒿(俗名油蒿, Artemisia ordosica)光合过程能量中分配对环境波动的相对变化及其长期调节机制, 该研究于2018年4-10月在宁夏盐池毛乌素沙地, 同时使用MONITORING-PAM多通道荧光监测仪和LI-6400XT便携式光合测量仪对黑沙蒿叶片的最小荧光产量(Fo)、最大荧光产量(Fm)、稳态荧光产量(Fs)、光下最大荧光产量(Fm′)、净光合速率(Pn)、暗呼吸速率(Rd)、蒸腾速率(E)和叶片气孔导度(gs)进行现场测定, 在实验室内计算比叶面积(SLA)、单位面积氮含量(Narea)、叶绿素含量(CChl)和叶绿素a/b (Chl a/b), 分析黑沙蒿光合过程能量分配中固碳耗能占比(ΦA)、光呼吸耗能占比(ΦPR)、调节性热耗散耗能占比(ΦNPQ)和非调节性热耗散耗能占比(ΦNO)与环境参数和叶性状参数之间的关系以及能量分配各组分之间的相对变化。结果表明, 光化学反应组分(ΦA、ΦPR)和热耗散组分(ΦNPQ、ΦNO)之间呈负相关竞争关系, 两组分内部呈正相关协同关系, E和ΦA、ΦPR正相关, 和ΦNPQ、ΦNO负相关。在低土壤含水量(SWC)和高饱和水汽压差(VPD)环境条件下, 黑沙蒿ΦA、ΦPR和SLA显著降低, ΦNPQ和ΦNO显著增加。研究认为, 在长期干旱或高蒸散条件下, 黑沙蒿通过降低SLA等途径避免水分的过度流失, 同时将部分过剩光能由光呼吸代谢途径转移到热耗散组分进行耗散。波动环境下黑沙蒿形态性状的变异和光合过程能量分配的长期调节机制, 反映了其利用形态与生理的协同可塑性对逆境的适应。 相似文献
6.
Frutos C. Marhuenda-Egea Sonsoles Piera-Velzquez Chiquinquir Cadenas Eduardo Cadenas 《Journal of Molecular Catalysis .B, Enzymatic》2000,10(6):555-563
Alkaline p-nitrophenylphosphate phosphatase (pNPPase) from the halophilic archaeon Halobacterium salinarum (previously halobium) was solubilized in reversed micelles of cetyltrimethylammonium bromide (CTAB) in cyclohexane with 1-butanol as cosurfactant. The hydrolysis reaction appears to follow Michaelis–Menten kinetics. The dependency of the maximum reaction rate (Vmax) on the water content θ (% v/v) (or ω0 value: molar ratio of water to surfactant concentrations) showed a bell-shaped curve for 0.3 M CTAB, but not for 0.2 M CTAB. The enzyme activity increased with the surfactant concentration at a constant ω0 value (10.27). When the surfactant concentration was increased at a constant θ, the enzyme activity decreased. The enzyme was more stable in reversed micelles than in aqueous media. 相似文献
7.
Yield stress of 6% (w/w) waxy maize (WXM), cross-linked waxy maize (CLWM), and cold water swelling (CWS) starches in xanthan gum dispersions: 0%, 0.35%, 0.50%, 0.70%, and 1.0% was measured with the vane method at an apparent shear rate of 0.05 s−1. The intrinsic viscosity of the xanthan gum was determined to be: 112.3 dL/g in distilled water at 25 °C. Values of the static (σ0s) and dynamic (σ0d) yield stress of each dispersion were measured before and after breaking down its structure under continuous shear, respectively. The WXM and CWS starches exhibited synergistic behavior, whereas the CLWM starch showed antagonistic effect with xanthan gum. The difference (σ0s − σ0d) was the stress required to break the inter-particle bonding (σb). The contributions of the viscous (σv) and network (σn) components were estimated from an energy balance model. In general, values of σb of the starch–xanthan gum dispersions decreased and those of σn increased with increase in xanthan gum concentration. 相似文献
8.
Concanavalin A induced apoptosis in murine macrophage PU5-1.8 cells through clustering of mitochondria and release of cytochrome c 总被引:2,自引:0,他引:2
Suen YK Fung KP Choy YM Lee CY Chan CW Kong SK 《Apoptosis : an international journal on programmed cell death》2000,5(4):369-377
Concanavalin A (ConA), normally a mitogen of T-lymphocytes, was found to be a cell cycle-independent apoptosis-inducing agent in cultured murine macrophage PU5-1.8 cells. This assertion is based on the following observations: (1) ConA increased the number of cells with hypo-diploid DNA in a dose dependent manner as revealed by flow cytometry; (2) ConA elicited DNA fragmentation and the cytotoxicity of ConA was suppressed by -D-methylmannoside which blocks the lectin site of ConA; (3) ConA was able to release cytochrome c (cyto c) into the cytosol of PU5-1.8 cells. When isolated mitochondria were incubated with ConA, release of cyto c was observed too. Interestingly, clustering of mitochondria was found in the cytosol under a confocal microscope after ConA treatment. When cells were incubated with ConA-FITC and subsequently with mitotracker red (a probe for mitochondria), co-localization of fluorescence signals was observed. These results suggest that ConA was delivered to the mitochondria, induced mitochondrial clustering and released cyto c. Our results also show that introduction of exogenous cyto c electroporationally into ConA-untreated cells elicited DNA fragmentation. On the other hand, introduction of specific antibody against cyto c into PU5-1.8 cells suppressed the ConA-mediated cell death. Taken together, our results indicate that ConA induced apoptosis in PU5-1.8 cells through mitochondrial clustering and release of cyto c and the release of cyto c was sufficient to elicit apoptosis in PU5-1.8 cells. 相似文献
9.
Zhi-Bo Li Jing-Yun Wang Bo Jiang Xiu-Li Zhang Li-Jia An Yong-Ming Bao 《Phytomedicine》2007,14(12):846-852
A new quinone compound, p-hydroxymethoxybenzobijuglone (HMBBJ), isolated from Juglans mandshurica by bioassay-guided fractionation, showed cytotoxic activity against HeLa cell line. Its chemical structure was determined by NMR and HREIMS spectra. In this paper, its ability to induce apoptosis in HeLa cells was studied for the first time. After treated with HMBBJ, the growth of HeLa cells was inhibited and cells displayed typical morphological apoptotic characteristics. Data from flow cytometry analysis showed that the HeLa cell cycle was arrested in the G2/M phase by HMBBJ, and the apoptotic rate of HeLa cells increased in a dose-dependent manner. Meanwhile, HMBBJ increased the expression of caspase-8, -3 and Bax, decreased the expression of Bcl-2, and lowered the ΔΨm. These findings reveal that HMBBJ could efficiently induce HeLa cells apoptosis through mitochondria dependent pathway and activation of the caspase cascade, and it may be a potential chemotherapeutic candidate for the treatment of cancer. 相似文献
10.
Y Ito P Pandey A Place M B Sporn G W Gribble T Honda S Kharbanda D Kufe 《Cell growth & differentiation》2000,11(5):261-267
The oleanane triterpenoid 2-cyano-3,12-dioxoolean-1,9-dien-28-oic acid (CDDO) is a multifunctional molecule that induces growth inhibition and differentiation of human myeloid leukemia cells. The present studies demonstrate that CDDO treatment results in apoptosis of U-937 and HL-60 myeloid leukemia cells. Similar to 1-beta-D-arabinofuranosylcytosine (ara-C), another agent that inhibits growth and induces apoptosis of these cells, CDDO induced the release of mitochondrial cytochrome c and activation of caspase-3. Overexpression of Bcl-X(L) blocked cytochrome c release, caspase-3 activation, and apoptosis in ara-C-treated cells. By contrast, CDDO-induced release of cytochrome c, and activation of caspase-3 were diminished only in part by Bcl-X(L). In concert with these findings, we demonstrate that CDDO, but not ara-C, activates caspase-8 and thereby caspase-3 by a cytochrome c-independent mechanism. The results also show that CDDO-induced cytochrome c release is mediated by caspase-8-dependent cleavage of Bid. These findings demonstrate that CDDO induces apoptosis of myeloid leukemia cells and that this novel agent activates an apoptotic signaling cascade distinct from that induced by the cytotoxic agent ara-C. 相似文献
11.
A new coulometric-potentiometric titration cuvette is described which permits accurate measurements of oxidation-reduction components in membranous systems. This cuvette has been utilized to measure the properties of cytochrome c oxidase in intact membranes of pigeon breast muscle mitochondria. The reducing equivalents accepted and donated by the portion of the respiratory chain with half-reduction potentials greater than 200 mV are equal to those required for the known components (cytochrome a3 and the high-potential copper plus cytochrome a, ‘visible copper’, cytochrome c1, cytochrome c, and the Rieske iron-sulfur protein). Titrations in the presence of CO show that formation of the reduced cytochrome a3-CO complex requires two reducing equivalents per cytochrome a3 (coulometric titration). Potentiometric titrations indicate (Lindsay, J.G., Owen, C.S. and Wilson, D.F. (1975) Arch. Biochem. Biophys. 169, 492–505) that both cytochromes a3 and the high-potential copper must be reduced in order to form the CO complex (n=2.0 with a CO concentration-dependent half-reduction potential, Em). By contrast, titrations in the presence of azide show that the Em value of the high-potential copper is unchanged by the presence of azide and thus azide binds with nearly equal affinity whether the copper is reduced or oxidized. 相似文献
12.
为了比较光系统II实际光化学量子效率(ΦPSII)对光的响应机理模型(简称机理模型)、负指数模型和指数模型的优缺点, 用LI-6400-40B光合作用测定仪控制CO2浓度和温度, 测量了剑叶金鸡菊(Coreopsis lanceolata)、黄荆(Vitex negundo)和大狼杷草(Bidens frondosa)的电子传递速率(ETR)对光的响应曲线(ETR-I)和ΦPSII对光的响应曲线(ΦPSII-I), 然后用这3个模型分别拟合了这些数据。拟合结果表明: 3个模型都可以较好地拟合这3种植物的ETR-I的响应数据和ΦPSII-I的响应数据, 但由指数模型拟合ETR-I和ΦPSII-I的响应数据得到相应的饱和光强(PARsat)和光系统II最大光能利用效率(Fv/Fm)之间存在显著差异, 且估算的饱和光强远低于实测值。由机理模型可知, ΦPSII不仅与光强的函数有关, 还与植物的内禀特性有关, 即与天线色素分子的本征光能吸收截面、激子的传递效率、能级的简并度、光化学反应常数、热耗散常数和处于最低激发态的平均寿命等参数有关。此外, 由机理模型还可知, ΦPSII随光强的增加而下降的原因是捕光色素分子的有效光能吸收截面随光强增加而降低。 相似文献
13.
Evidence is presented suggesting, for the first time, that the protein foldability metric σ = (Tθ − Tf) / Tθ, where Tθ and Tf are, respectively, the collapse and folding transition temperatures, could be used also to measure the foldability of RNA sequences. These results provide further evidence of similarities between the folding energy landscapes of proteins and RNA. The importance of σ is discussed in the context of the in silico design of rapidly foldable RNA sequences. 相似文献
14.
In permeabilized lacrimal acinar cells, cyclic ADP-ribose (cADP-ribose) and inositol 1,4,5-trisphosphate (Ins(1,4,5)P3) release Ca2+ in a dose dependent manner from distinct thapsigargin-sensitive Ca2+ pools. Ryanodine specifically blocks the Ca2+ response to cADP-ribose, whereas heparin strongly reduces the response to Ins(1,4,5)P3 application. GTP causes a rapid Ca2+ release by a ryanodine- and heparin-insensitive mechanism and potentiates Ins(1,4,5)P3 but not cADP-ribose evoked Ca2+ release. It is estimated that cADP-ribose can release 16 μmol Ca2+/I cells, whereas Ins(1,4,5)P3 can mobilize 55 μmol Ca2+/I cells. The results suggest that cADP-ribose and Ins(1,4,5)P3 release Ca2+ from distinct internal stores and that a third Ca2+ pool exists which can selectively interact with the Ins(1,4,5)P3-sensitive Ca2+ store by a GTP-mediated process. 相似文献
15.
16.
Fulai Liu Ri Song Xiaoyan Zhang Ali Shahnazari Mathias N. Andersen Finn Plauborg Sven-Erik Jacobsen Christian R. Jensen 《Environmental and Experimental Botany》2008,63(1-3):385-391
The objective of this study was to develop a simple mechanistic model to predict the magnitude of ABA signalling ([X-ABA]) of potatoes (Solanum tuberosum L.) exposed to partial root-zone drying (PRD). Potatoes were grown in pots in a glasshouse with the roots split equally between two soil columns. At tuber initiation stage, plants were subjected to three irrigation treatments: (1) both soil columns were fully irrigated (FI) daily to a volumetric soil water content (θ) of 18.0%; (2) PRD, in which one soil column was irrigated daily to 18.0% while the other was allowed to dry, and the irrigation was shifted between columns when the θ of the drying soil column had decreased to 7–8%; (3) non-irrigation (NI), where irrigation was withheld after onset of treatments and lasted for 5 days until θ had decreased to 7%. In the PRD plants, the fraction of soil water extraction (FSWE) by the dry roots declined exponentially with declining soil water potential (Ψsoil-dry); however, after shifting of irrigation, the previously dried roots immediately recovered the full capacity of water uptake. During the first PRD drying cycle, FI plants had the highest stomatal conductance (gs), and followed by PRD plants and NI plants had the lowest gs. Photosynthesis (A) was similar for FI and PRD plants, and was significantly lower for the NI plants only on 3–4 days after treatment. In the NI plants, a linear relationship between Ψsoil and [X-ABA] was obtained. Based on these relationships, a simple model predicting [X-ABA] in the PRD plants ([X-ABA]PRD) was developed. Assuming that a constant [X-ABA] of 115 nM (similar to that found in the FI plants) originated from the wet roots; the simulation results indicated that irrigation should be shifted between the two sides when Ψsoil-dry had decreased to −80 kPa, and [X-ABA]PRD had reached a peak of ca. 150 nM. However, the [X-ABA]PRD predicted by the model was significantly lower than the measured value; whilst a simple average of [X-ABA] from the wet and the dry soil columns based on the [X-ABA]–Ψsoil relationship better predicted [X-ABA]PRD. 相似文献
17.
Saito Y Nishio K Ogawa Y Kimata J Kinumi T Yoshida Y Noguchi N Niki E 《Free radical research》2006,40(6):619-630
The turning point between apoptosis and necrosis induced by hydrogen peroxide (H2O2) have been investigated using human T-lymphoma Jurkat cells. Cells treated with 50 μM H2O2 exhibited caspase-9 and caspase-3 activation, finally leading to apoptotic cell death. Treatment with 500 μM H2O2 did not exhibit caspase activation and changed the mode of death to necrosis. On the other hand, the release of cytochrome c from the mitochondria was observed under both conditions. Treatment with 500 μM H2O2, but not with 50 μM H2O2, caused a marked decrease in the intracellular ATP level; this is essential for apoptosome formation. H2O2-reducing enzymes such as cellular glutathione peroxidase (cGPx) and catalase, which are important for the activation of caspases, were active under the 500 μM H2O2 condition. Prevention of intracellular ATP loss, which did not influence cytochrome c release, significantly activated caspases, changing the mode of cell death from necrosis to apoptosis. These results suggest that ATP-dependent apoptosome formation determines whether H2O2-induced cell death is due to apoptosis or necrosis. 相似文献
18.
Atsushi Ando Kunio Kaiho Hodaka Kawahata Takeshi Kakegawa 《Palaeogeography, Palaeoclimatology, Palaeoecology》2008,260(3-4):463-476
In order to elucidate early Aptian marine paleotemperature evolution across the period of enhanced organic carbon (Corg)-burial [Oceanic Anoxic Event (OAE) 1a], stable isotope analyses were performed on pelagic limestones at Deep Sea Drilling Project Site 463, central Pacific Ocean. The δ18O data exhibit a distinct anomaly by ~ − 2‰ spanning the OAE 1a interval (i.e., a ~ 6 m-thick, phytoplanktonic Corg-rich unit constrained by magneto-, bio- and δ13C stratigraphy). Elucidation of paleotemperature significance of the δ18O shift is made by taking account of recent Sr/Ca evidence at the same section, which revealed that geochemical signals in carbonate-poor lithologies are relatively unaltered against burial diagenesis. By discriminating δ18O values from carbonate-poor samples (CaCO3 contents = 5–30 wt.%), it appears that an abrupt rise in sea-surface temperatures (SSTs) by 8 °C (= − 1.7‰ shift in δ18O) occurred immediately before OAE 1a, whereas a cooling mode likely prevailed during the peak Corg-burial. In terms of its stratigraphic relationship as to the Corg-rich interval and to a pronounced negative δ13C excursion, as well as its timescale, the observed SST rise resembles those associated with the Paleocene–Eocene thermal maximum and, more strikingly, Jurassic Toarcian OAE. This observation is consistent with the hypothesis that these paleoenvironmental events were driven by a common causal mechanism, which was likely initiated by the greenhouse effect via massive release of CH4 or CO2 from the isotopically-light carbon reservoir and terminated by a negative productivity feedback. 相似文献
19.
The critical event of the intrinsic pathway of apoptosis following transient global brain ischemia is the release of cytochrome c from the mitochondria. In vitro studies have shown that insulin can signal specifically via phosphatidylinositol-3-OH-kinase (PI3-K) and Akt to prevent cytochrome c release. Therefore, insulin may exert its neuroprotective effects during brain reperfusion by blocking cytochrome c release. We hypothesized that insulin acts through PI3-K, Akt, and Bcl-2 family proteins to inhibit cytochrome c release following transient global brain ischemia. We found that a single bolus of insulin given immediately upon reperfusion inhibited cytochrome c release for at least 24 h, and produced a fivefold improvement in neuronal survival at 14 days. Moreover, insulin's ability to inhibit cytochrome c release was completely dependent on PI3-K signaling and insulin induces phosphorylation of Akt through PI3-K. In untreated animals, there was an increase in mitochondrial Bax at 6 h of reperfusion, and Bax binding to Bcl-XL was disrupted at the mitochondria. Insulin prevented both these events in a PI3-K-dependent manner. In summary, insulin regulates cytochrome c release through PI3-K likely by activating Akt, promoting the binding between Bax and Bcl-XL , and by preventing Bax translocation to the mitochondria. 相似文献
20.
Enhancement of radiation-induced apoptosis by 6-formylpterin 总被引:7,自引:0,他引:7
Cui ZG Kondo T Ogawa R Feril LB Zhao QL Wada S Arai T Makino K 《Free radical research》2004,38(4):363-373
Radiation-induced apoptosis and its possible enhancement in the presence of 6-formylpterin (6-FP), a metabolite of folic acid, were examined in human myelomonocytic lymphoma U937 cells. When cells were treated with 6-FP at a nontoxic concentration of 300 μM, and then exposed to X-rays at a dose of 10 Gy, significant enhancement of radiation-induced apoptosis as determined by nuclear morphological change, phosphatidylserine (PS) externalization and DNA fragmentation were observed. Flow cytometry for the detection of intracellular hydrogen peroxide (H2O2) revealed that 6-FP increased the formation of intracellular H2O2, which further increased when the cells were irradiated. Decrease of mitochondria trans-membrane potential (MMP), release of cytochrome c from mitochondria, and activation of caspase-3 were enhanced after the combined treatment. Remarkable activation of protein kinase C δ (PKC δ) and its translocation from cytosol to mitochondria were detected in combined treatment. Increase of intracellular Ca2+ concentrations ([Ca2+]i) was also observed, however, neither calpain I nor calpain II could inhibit the apoptosis. In addition, c-Jun NH2-terminal kinase ( JNK) activation was not enhanced in the combined treatment. A protein involved in a caspase-independent apoptosis pathway, apoptosis inducing factor (AIF), remained unchanged even 3 h after treatment. These results indicate that intracellular H2O2 generated by 6-FP enhances radiation-induced apoptosis via the mitochondria-mediated caspase-dependent pathway, with the active involvement of PKC δ. 相似文献