Adenosine triphosphate induced cell death: Mechanisms and implications in cancer biology and therapy

Adenosine triphosphate(ATP)induced cell death(AICD)is a critical cellular process that has garnered substantial scientific interest for its profound relevance to cancer biology and to therapeutic interventions.This comprehensive review unveils the intricate web of AICD mechanisms and their intricate connections with cancer biology.This review offers a comprehensive framework for comprehending the multifaceted role of AICD in the context of cancer.This is achieved by elucidating the dynamic interplay between systemic and cellular ATP homeostasis,deciphering the intricate mechanisms governing AICD,elucidating its intricate involvement in cancer signaling pathways,and scrutinizing validated key genes.Moreover,the exploration of AICD as a potential avenue for cancer treatment underscores its essential role in shaping the future landscape of cancer therapeutics.

Autophagy occurs within an hour of adenosine triphosphate treatment after nerve cell damage:the neuroprotective effects of adenosine triphosphate against apoptosis

After hypoxia, ischemia, or inflammatory injuries to the central nervous system, the damaged cells release a large amount of adenosine triphosphate, which may cause secondary neuronal death. Autophagy is a form of cell death that also has neuroprotective effects. Cell Counting Kit assay, monodansylcadaverine staining, flow cytometry, western blotting, and real-time PCR were used to determine the effects of exogenous adenosine triphosphate treatment at different concentrations （2, 4, 6, 8, 10 mmol/L） over time （1, 2, 3, and 6 hours） on the apoptosis and autophagy of SH-SY5Y cells. High concentrations of extracellular adenosine triphosphate induced autophagy and apoptosis of SH-SYSY cells. The enhanced autophagy first appeared, and peaked at 1 hour after treatment with adenosine triphosphate. Cell apoptosis peaked at 3 hours, and persisted through 6 hours. With prolonged exposure to the adenosine triphosphate treatment, the fraction of apoptotic cells increased. These data suggest that the SH-SY5Y neural cells initiated autophagy against apoptosis within an hour of adenosine triphosphate treatment to protect themselves against injury.

Inhibitory effects of extracellular adenosine triphosphate on growth of esophageal carcinoma cells

AIM： To study the growth inhibitory effects of ATP on TE-13 human squamous esophageal carcinoma cellsin vitro.METHODS： NTT assay was used to determine the inhibition of proliferation of ATP or adenosine （ADO） on TE-13 cell line. The morphological changes of TE-13 cells induced by ATP or ADO were observed under fluorescence light microscope by acridine orange （AO）/ethidium bromide （EB） double stained cells. The intemudeosomal fragmentation of genomic DNA was detected by agarose gel electrophoresis. The apoptotic rate and cell cycle after treatment with ATP or ADO were determined by flow cytometry.RESULTS： ATP and ADO produced inhibitory effects on TE-13 cells at the concentration between 0.01 and 1.0 mmol/L. The ICs0 of TE-13 cells exposed to ATP or ADO for 48 and 72 h was 0.71 or 1.05, and 0.21 or 0.19 mmol/L, respectively. The distribution of cell cycle phase and proliferation index （PI） value of TE-13 cells changed, when being exposed to ATP or ADO at the concentrations of 0.01, 0.1, and 1 mmol/L for 48 h. ATP and ADO inhibited the cell proliferation by changing the distribution of cell cycle phase via either G0/G1 phase （ATP or ADO, 1 mmol/L） or S phase （ATP, 0.1 mmol/L） arrest. Under light microscope, the tumor cells exposed to 0.3 mmol/L ATP or ADO displayed morphological changes of apoptosis. A ladder-like pattern of DNA fragmentation was obtained from TE-13 cells treated with 0.1-1 mmol/L ATP or ADO in agarose gel electrophoresis. ATP and ADO induced apoptosis of TE-13 cells in a dose-dependent manner at the concentration between 0.03 and 1 mmol/L. The maximum apoptotic rate of TE-13 cells exposed to ATP or ADO for 48 h was 16.63% or 16.9%, respectively.CONCLUSION： ATP and ADO inhibit cell proliferation, arrest cell cycle, and induce apoptosis of TE-13 cell line.

Adenosine triphosphate promotes locomotor recovery after spinal cord injury by activating mammalian target of rapamycin pathway in rats

The mammalian target of rapamycin （mTOR） pathway plays an important role in neuronal growth, proliferation and differentiation. To better understand the role of mTOR pathway involved in the induction of spinal cord injury, rat models of spinal cord injury were established by modified Allen＇s stall method and interfered for 7 days by intraperitoneal administration of mTOR activator adenosine triphosphate and mTOR kinase inhibitor rapamycin. At 1-4 weeks after spinal cord injury induction, the Basso, Beattie and Bresnahan locomotor rating scale was used to evaluate rat locomotor function, and immunohistochemical staining and western blot analysis were used to detect the expression of nestin （neural stem cell marker）, neuronal nuclei （neuronal marker）, neuron specific enolase, neurofilament protein 200 （axonal marker）, glial fibrillary acidic protein （astrocyte marker）, Akt, mTOR and signal transduction and activator of transcription 3 （STAT3）. Results showed that adenosine triphosphate-mediated Akt/mTOR/STAT3 pathway increased endogenous neural stem cells, induced neurogenesis and axonal growth, inhibited excessive astrogliosis and improved the locomotor function of rats with spinal cord injury.

Efficient production of cyclic adenosine monophosphate from adenosine triphosphate by the N-terminal half of adenylate cyclase from Escherichia coli

In this study,we aimed at developing an efficient biocatalytic process for bio-production of cyclic adenosine monophosphate(c AMP)from adenosine triphosphate(ATP).First,adenylate cyclase from Escherichia coli MG1655(EAC)and Bordetella Pertussis(BAC)were expressed in E.coli BL21(DE3)and comparatively analyzed for their activities.As a result,EAC from E.coli MG1655 exhibited a higher activity.However,amount of EAC were obtained in an insoluble form.Therefore,we expressed the first 446 amino acids of EAC(EAC446)to avoid the inclusion body.The effects of induction temperature,incubation time,and incubation p H were further evaluated to improve the expression of EAC446.Subsequently,the reaction process for the production of c AMP with ATP as a starting material was investigated.As none of c AMP was detected in the whole-cell based biocatalytic process,the reaction catalyzed by the crude enzyme was determined for c AMP production.What's more,the reaction temperature,reaction p H,metal ion additives and substrate concentration was optimized,and the maximum c AMP production of 18.45 g·L^-1was achieved with a yield of 95.4%after bioconversion of 6 h.

Protective effect of exogenous adenosine triphosphate on hypothermically preserved rat liver

AIM:To clarify the protective effect of exogenous adenosine triphosphate(ATP)on hypothermically preserved rat livers. METHODS:Establishment of continuous hypothermic machine perfusion model,detection of nucleotides in hepatocytes with HPLC,measurement of activities of LDH and AST in the perfusate,observation of histopathological changes in different experiment groups,and autoradiography were carried out to reveal the underlying mechanism of the protective effect of ATP. RESULTS:The intracellular levels of ATP and EC decreased rapidly after hypothermic preservation in control group,while a higher ATP and EC level,and a slower decreasing rate were observed when ATP-MgCl_2 was added to the perfusate (P<0.01).As compared with the control group,the activities of LDH and AST in the ATP-MgCl_2 group were lower(P<0.05). Furthermore,more severe hepatocyte damage and neutrophil infiltration were observed in the control group.Radioactive [α-^(32)P]ATP entered the hypothermically preserved rat hepatocytes. CONCLUSION:Exogenous ATP has a protective effect on rat livers during hypothermical preservation.However,Mg^(2+) is indispensable,addition of ATP alone produces no protective effect.The underlying mechanism may be that exogenous ATP enters the hypothermically preserved rat liver cells.

Electroacupuncture improves neuropathic pain Adenosine, adenosine 5'-triphosphate disodium and their receptors perhaps change simultaneously

Applying a stimulating current to acupoints through acupuncture needles–known as electroacupuncture–has the potential to produce analgesic effects in human subjects and experimental animals. When acupuncture was applied in a rat model, adenosine 5-triphosphate disodium in the extracellular space was broken down into adenosine, which in turn inhibited pain transmission by means of an adenosine A1 receptor-dependent process. Direct injection of an adenosine A1 receptor agonist enhanced the analgesic effect of acupuncture. The analgesic effect of acupuncture appears to be mediated by activation of A1 receptors located on ascending nerves. In neuropathic pain, there is upregulation of P2X purinoceptor 3 （P2X3） receptor expression in dorsal root ganglion neurons. Conversely, the onset of mechanical hyperalgesia was diminished and established hyperalgesia was significantly reversed when P2X3 receptor expression was downregulated. The pathways upon which electroacupuncture appear to act are interwoven with pain pathways, and electroacupuncture stimuli converge with impulses originating from painful areas. Electroacupuncture may act via purinergic A1 and P2X3 receptors simultaneously to induce an analgesic effect on neuropathic pain.

Nicotinamide Adenine Dinucleotide and Adenosine Triphosphate Oscillations Caused by Gradual Entry of Substrates within Mitochondria

Nicotinamide adenine dinucleotide (NAD) oscillation was observed when the isolated mitochondria were immersed in a pyruvate solution. In addition, when an adenosine diphosphate (ADP) was added to the mitochondrial suspension containing pyruvate, adenosine triphosphate (ATP) oscillation was observed as well as NADH oscillation. At this time, the pH within mitochondria also oscillated. It was found that the oscillatory reaction of NADH caused by the membrane permeation of pyruvate continues, causing the oscillation of NADH and H+ in the subsequent reactions. The pH oscillation led to the ATP oscillation. It is considered that the oscillatory reaction caused by the gradual entry of pyruvate into mitochondria was thought to be carried over to both the citric acid cycle and the respiratory chain, ultimately leading to the ATP oscillation in oxidative phosphorylation. Similarly, it was found that membrane permeation of malate causes the gradual occurrence of NADH, at which point NADH oscillates, followed by an oscillatory reaction of the respiratory chain, and finally ATP oscillation. It was found that the oscillations of NADH and ATP occur without going through the citric acid cycle. Oscillations of NADH and other intermediates in both the citric acid cycle and respiratory chain were also confirmed by experiments using semipermeable membranes. These results support our hypothesis that the gradual entry of the substrate by membrane permeation triggers an oscillatory reaction of the enzyme, which is also carried over to subsequent reactions.

腺苷负荷与ATP负荷评估冠状动脉微血管疾病中的不良反应分析

背景 冠状动脉微血管疾病(CMVD)的诊疗一直是非冠状动脉阻塞性缺血性心脏病的重点。腺苷注射液和ATP注射液是目前测定冠状动脉血流储备(CFR)评估CMVD的临床常用负荷药物,两者有所关联,但具有显著区别。ATP是腺苷的前体,其价格低廉且血管扩张机制与腺苷类似,临床上常代替腺苷,但忽视了其潜在的不良反应。目的 比较腺苷负荷与ATP负荷在评估CMVD过程中的不良反应发生率。方法 选取2019年6月—2020年7月因典型心绞痛就诊于陕西省人民医院心内科行冠状动脉造影术/冠状动脉CT血管造影术(CTA)明确各支冠状动脉残余狭窄直径<50%的患者170例,依据随机数字表法分为腺苷组和ATP组,腺苷组88例,ATP组82例。腺苷组给予腺苷注射液负荷测定CFR,ATP组采用ATP负荷测定CFR,检测过程中记录患者的血压、心率、扫描时间及不良反应发生情况。结果 与腺苷组相比,ATP组患者胸闷[61.0%(50/82)和20.4%(18/88)]、头晕[72.0%(59/82)和31.8%(28/88)]、头痛[68.3%(56/82)和11.4%(10/88)]、胃肠道不适[13.4%(11/82)和4.5%(4/88)]、心悸[69.5%(57/82)和5.7%(5/88)]、气促[40.2%(33/82)和2.3%(2/88)]、大汗[28.0%(23/82)和3.4%(3/88)]、潮热[19.5%(16/82)和2.3%(2/88)]、颜面潮红[13.4%(11/82)和4.5%(4/88)]的发生率均较高(P<0.05);两组患者神经过敏、耳鸣、咽干、颈部不适的不良反应发生率比较,差异无统计学意义(P>0.05)。结论 与ATP负荷相比,腺苷负荷测定CFR的不良反应发生率更低。

亚慢性PM_(2.5)和O_(3)共同暴露对大鼠鼻黏膜ATP总量及ATP酶活性的影响

目的:探讨细颗粒物(fine particle matter,PM_(2.5))和臭氧(ozone,O_(3))亚慢性共同暴露对大鼠鼻黏膜组织腺嘌呤核苷三磷酸(adenosine triphosphate,ATP)总量及ATP酶活性的影响。方法:采用随机数字表法将20只雄性Sprague Dawley(SD)大鼠均分为对照组和暴露组,每组各10只,分别饲养于常规清洁级环境和本团队既往所搭建的大气污染物暴露系统中,连续暴露208 d。暴露期间,监测暴露系统内PM_(2.5)和O_(3)浓度,采用自测和站点数据相结合的方法对暴露系统内PM_(2.5)和O_(3)进行综合评估。在暴露第208天处死大鼠取心、肝、脾、肾、睾丸等主要器官和鼻黏膜组织,称量各脏器重量并计算脏器系数。利用所收集鼻黏膜组织,使用生物发光法测定ATP总量,使用分光光度法检测Na^(+)-K^(+)-ATP酶和Ca^(2+)-ATP酶活性。使用两独立样本t检验比较各指标组间差异。结果:自第3周开始至暴露结束,暴露组大鼠体质量高于对照组(P<0.05),两组间脏器系数差异无统计学意义。暴露组日均PM_(2.5)浓度为(30.68±19.23)μg/m3,O_(3)最大8 h浓度(O_(3)-8 h)为(82.45±35.81)μg/m3。暴露组大鼠鼻黏膜组织ATP化学发光值(792.4±274.1)IU/L低于对照组(1126.8±218.1)IU/L,鼻黏膜组织Na^(+)-K^(+)-ATP酶活性(1.53±0.85)U/mg低于对照组(4.31±1.60)U/mg(P<0.05)。对照组和暴露组鼻黏膜组织的蛋白含量分别为(302.14±52.51)mg/L和(234.58±53.49)mg/L,Ca^(2+)-ATP酶活性分别为(0.81±0.27)U/mg和(0.99±0.73)U/mg,组间差异均无统计学意义。结论:亚慢性PM_(2.5)和O_(3)共同暴露可能影响大鼠鼻黏膜组织供氧能力。

ATP-ACLY在光线性角化病和皮肤鳞状细胞癌中的表达及意义

目的比较三磷酸腺苷-柠檬酸裂解酶(ATP-ACLY)在正常皮肤、光线性角化病(AK)和皮肤鳞状细胞癌(cSCC)皮损组织中的表达情况。方法在2020年10月—2021年6月就诊于本院的患者中,收集组织病理确诊为AK、cSCC以及正常皮肤的石蜡包埋组织(FFPE)标本各30例。用免疫组化SABC法检测ACLY在30例正常皮肤、30例AK和30例cSCC皮损组织标本中的表达情况。结果cSCC组中ACLY的阳性细胞率为(27.7±6.7)%,显著高于正常皮肤组(18.8±1.7)%和AK组(20.4±6.8)%。ACLY的阳性细胞率在正常皮肤组和AK组之间的差异无统计学意义(P>0.05)。ACLY在正常皮肤、AK和cSCC皮损组织中染色强阳性率分别为0.00%(0/30)、3.33%(1/30)和23.33%(7/30),cSCC组与正常皮肤组的差异有统计学意义(P<0.05)。结论ACLY的高表达可能与cSCC的发病机制相关。

发酵乳和乳饮料中乳酸菌活菌数ATP检测方法的开发与应用

乳酸菌活菌数作为发酵乳和乳酸菌饮料的产品质量属性,同时作为国家风险抽检项目,目前的检测方法存在操作烦琐、检测周期长、结果滞后等缺点,无法满足企业产品卖点宣称及质量控制,故针对发酵乳和乳饮料中乳酸菌活菌数的快速检测方法进行开发、研究,旨在提高检测结果准确性、稳定性及缩短检测周期。每种微生物中的腺嘌呤核苷三磷酸(Adenosine Triphosphate,ATP)含量都是基本恒定的,而ATP的相对发光单位(Relative Luminescence Unit,RLU)与ATP含量呈线性关系,通过建立产品中乳酸菌数量与ATP的RLU(相对发光单位)的相关关系开发乳酸菌快速检测方法。通过试验证实该方法与国家标准检测方法具有一致性,能够快速、准确地检测产品中乳酸菌数活菌数,为生产销售流通中的质量监测提供一种快捷方便的方法。

Adenosine triphosphate-responsive carbon dots nanoreactors for T_(1)-weighted magnetic resonance imaging-guided tumor chemodynamic therapy

There are various strategies to conduct tumor microenvironment(TME)stimulus-responsive(e.g.,acid,H_(2)O_(2)or glutathione)nanoreactors for increasing the efficiency of chemodynamic therapy(CDT).Among these,the exploitation of adenosine triphosphate(ATP,another overexpressed biomarker in TME)-responsive nanoreactors for tumor CDT is still challenging.Herein,the ATP-responsive iron-doped CDs(FeCDs)were firstly prepared and then coassembled with glucose oxidase(GOx)to obtain FeCDs/GOx liposomes as ATP-responsive nanoreactors.Under TME conditions,the nanoreactors initially released FeCDs and GOx.Subsequently,with the existence of ATP,iron ions were rapidly released from the FeCDs to trigger Fenton/Fenton-like reactions for generating·OH.Meanwhile,the T_(1)-weighted magnetic resonance imaging(MRI)was achieved due to the released iron ions.Moreover,the GOx converted endogenous glucose in tumor to gluconic acid and H_(2)O_(2)to satisfy the requirement of·OH generation.In vitro as well as in vivo experiments illustrated that the obtained ATP-responsive CD nanoreactors could be used as a versatile nanotheranostics for simultaneously T_(1)-weighted MRI-guided tumor CDT.This work presents a new ATP-responsive nanoreactor with selfsupplied H_(2)O_(2)for multifunctional nanotheranostic applications.

Adenosine triphosphate mediates the pain tolerance effect of manual acupuncture at Zusanli(ST36) in mice

OBJECTIVE:To investigate the mechanisms behind the effects of acupuncture in Traditional Chinese Medicine,we delved into the adenosine triphosphate/peripheral purinergic P2X receptor 3(ATP/P2X3)receptor signaling system as an indicator of the body's energy state,commonly referred to as"Qi".METHODS:The tail-flick test was utilized to explore the impact of acupuncture on pain tolerance threshold(PTT)in mice,while also assessing adenosine(ADO)levels and adenylate energy charge(EC)at Zusanli(ST36).The study further investigated the dose-dependent effects of acupuncture on PTT and ADO levels at Zusanli(ST36).To shed light on the underlying mechanisms of acupuncture's effects,the study examined the impact of ATP,a P2X3 receptor antagonist,and adenosine disodium on PTT following acupuncture administration.RESULTS:Acupuncture at Zusanli(ST36)led to significant improvements in PTT in mice,with the most effective interventions being twirling for 2 min and needle retention for 28 min.These interventions also resulted in significant increases in ATP levels.The effects of acupuncture were further augmented by administration of different doses of ATP at Zusanli(ST36),and pretreatment with a P2X3 receptor antagonist decreased PTT.Adenylate EC peaked at 30 min after intraperitoneal injection of ATP,and pretreatment with various doses of i.p.ATP 30 min prior to acupuncture increased PTT in a dose-dependent manner.Additionally,pretreatment with an i.p.or intramuscular injection of adenosine disodium enhanced the effects of acupuncture.CONCLUSION:This research provides compelling evidence that ATP is involved in the regulation of PTT through acupuncture,revealing new avenues for achieving enhanced clinical outcomes.

ATP生成和自噬调节在急性胰腺炎中的治疗潜力

急性胰腺炎(AP)是一种由多因素导致的胰酶在胰腺内激活后引发的胰腺组织自身消化、水肿、出血甚至坏死的炎症反应。目前关于AP的发生发展机制尚未完全阐明,且缺乏特异性AP治疗手段。胰腺腺泡细胞腺苷三磷酸(ATP)供应不足和自噬功能障碍是AP的早期细胞内表现,恢复腺泡细胞ATP供应和溶酶体-自噬系统功能有利于AP的治疗。因此,深入研究ATP生成障碍、自噬受损等在AP发生发展中的作用,可以为AP的临床治疗提供新思路。

Electroacupuncture-induced neuroprotection against focal cerebral ischemia in the rat is mediated by adenosine A1 receptors

The activation of adenosine A1 receptors is important for protecting against ischemic brain injury and pretreatment with electroacupuncture has been shown to mitigate ischemic brain insult. The aim of this study was to test whether the adenosine A1 receptor mediates electroacupuncture pretreatment-induced neuroprotection against ischemic brain injury. We first performed 30 minutes of electroacupuncture pretreatment at the Baihui acupoint（GV20）, delivered with a current of 1 mA, a frequency of 2/15 Hz, and a depth of 1 mm. High-performance liquid chromatography found that adenosine triphosphate and adenosine levels peaked in the cerebral cortex at 15 minutes and 120 minutes after electroacupuncture pretreatment, respectively. We further examined the effect of 15 or 120 minutes electroacupuncture treatment on ischemic brain injury in a rat middle cerebral artery-occlusion model. We found that at 24 hours reperfusion,120 minutes after electroacupuncture pretreatment, but not for 15 minutes, significantly reduced behavioral deficits and infarct volumes. Last, we demonstrated that the protective effect gained by 120 minutes after electroacupuncture treatment before ischemic injury was abolished by pretreatment with the A1-receptor antagonist 8-cyclopentyl-1,3-dipropylxanthine（1 mg/kg, intraperitoneally）. Our results suggest that pretreatment with electroacupuncture at the Baihui acupoint elicits protection against transient cerebral ischemia via action at adenosine A1 receptors.

斑点追踪技术评价慢性冠状动脉综合征微循环病变左心室收缩功能及ATP负荷的影响

目的应用斑点追踪技术(STE)评价慢性冠状动脉综合征(CCS)微循环病变患者早期左心室收缩功能及腺苷三磷酸(ATP)负荷的影响。资料与方法回顾性收集2019年9月—2021年9月浙江大学医学院附属第二医院56例CCS(包括微循环病变33例,无微循环病变23例),并选取24例正常者为对照组,采用STE评估左心室整体和局部心肌纵向应变及ATP负荷的影响。结果微循环病变组左心室整体纵向应变(GLS)及前间隔、前壁、前侧壁和下壁心肌纵向应变绝对值低于对照组(F=4.47、2.75、2.60、6.24、3.70,P均<0.05),无微循环病变组左心室GLS及前间隔、前壁、下侧壁、下壁和后间隔心肌纵向应变结果与对照组比较差异无统计学意义(F=4.47、2.75、2.60、1.02、3.70、1.06,P均>0.05)。ATP负荷后,与各组基础状态比较,微循环病变组左心室GLS和前间隔、前壁、前侧壁、下侧壁、下壁及后间隔心肌的纵向应变绝对值增加(t/Z=4.31、3.52、4.95、3.32、3.22、2.52、4.07,P均<0.05),无微循环病变组左心室GLS和前间隔、前壁、前侧壁、下壁和后间隔心肌的纵向应变绝对值增加(t/Z=6.07、2.28、4.12、5.02、3.22、3.96,P均<0.05)。结论CCS微循环病变患者可能存在早期左心室收缩功能受损,ATP负荷可改善CCS患者的左心室心肌收缩功能。

葱、姜和紫苏的添加对预制细点圆趾蟹挥发性化合物和ATP及关联产物变化的影响

考察葱、姜和紫苏作为佐菜对预制细点圆趾蟹食用品质的影响。感官评价结果表明,3种佐菜均具有去腥效果,且以葱去腥作用最强,姜能赋予蟹肉较强的辛辣味,紫苏使蟹肉气味丰富浓郁。4组蟹肉挥发性气味成分存在显著性差异,佐菜的添加使蟹肉挥发性物质种类更丰富。对照组蟹肉挥发性化合物共鉴定出47种,葱组50种,其中,己醛、庚醛、辛醛、壬醛和1-辛烯-3-醇等具有腥味的化合物相对含量降低;姜组增加到56种,含醛类14种,癸醛、3-甲基丁醛等赋予蟹肉较好的水果香、坚果香和花香;紫苏组检测出70种挥发性化合物,含15种关键挥发性化合物,丰富的酮类、酯类和吡嗪类使其风味变得更加独特。添加佐菜不会改变蟹肉三磷酸腺苷在高温下的降解途径,但会影响关联产物的降解量,姜组中腺嘌呤的含量最高为1.95 mg/100 g;紫苏组中肌苷酸的含量最高为72.52 mg/100 g,相应其鲜味也表现突出;葱组中次黄嘌呤核苷和次黄嘌呤的含量分别为2.12 mg/100 g和3.69 mg/100 g,含量最低,相应其苦味最弱。本研究直观反映了佐菜对蟹肉风味的影响,为优质细点圆趾蟹预制产品的研发提供技术理论基础。

基于Al^(3+)与ATP协同增敏荧光法快速检测牛奶中氧氟沙星

目的利用铝离子(aluminumions,Al^(3+))与三磷酸腺苷(adenosinetriphosphate,ATP)对氧氟沙星(ofloxacin,OFL)荧光的协同增强特性,建立一种灵敏、快速、准确地定量检测牛奶中OFL的方法。方法通过Al^(3+)与ATP协同增强OFL荧光强度对OFL进行定量检测,对荧光激发波长、pH、反应温度、反应时间等条件进行优化,并在实际样品牛奶中进行加标回收实验。结果Al^(3+)与ATP可协同增强OFL溶液荧光强度,并使荧光发射峰红移以实现对OFL选择性检测。在最优实验条件(pH 7.0、反应时间5 min和反应温度25℃)下,在0.1~100.0μmol/L范围内,OFL荧光强度与其浓度呈现良好的线性关系,其相关系数r^(2)为0.9973,检出限为4.48 nmol/L。在两种牛奶中的加标回收率分别为98.59%~102.48%和87.32%~104.29%,相对标准偏差小于5%。结论本方法具有操作简便、灵敏、快速等优点,并成功地用于测定牛奶中的OFL,具有良好的回收率,为牛奶中OFL的灵敏快速检测提供了一种可行的方法。

Changes in P2Y purinoreceptor-mediated intracellular calcium signal pathways results in inositol-1, 4, 5-triphosphate-sensitive calcium stores in rat small trigeminal ganglion neurons

BACKGROUND： Most of the currently available information on purinergic receptors （P2Rs） involved in pain transmission is based on results obtained in dorsal root ganglion or the spinal cord. However, the mechanism of P2Rs in trigeminal neuralgia remains unclear. OBJECTIVE： To investigate changes in the P2R-mediated calcium signaling pathway in nociceptive trigemJnal ganglion neurons. DESIGN, TIME AND SETTING： In vitro experiments were conducted at the Patch-Clamp Laboratory of Comprehensive Experiment Center of Anhui Medical University, China from September 2008 to June 2009. MATERIALS： Thapsigargin, caffeine, suramin, and adenosine 5＇-triphosphate were purchased from Sigma, USA. METHODS： Using Fura-2-based microfluorimetry, intracellular calcium concentration （[Ca^2＋]i） was measured in freshly isolated adult rat small trigeminal ganglion neurons before and after drug application. MAIN OUTCOME MEASURES： Fluorescent intensities were expressed as the ratio F340/F380 to observe [Ca^2＋]i changes. RESULTS： In normal extracellular solution and Ca^2＋-free solution, application of thapsigargin （1 μmol/L）, a sarcoplasmic reticulum Ca^2＋ pump adenosine 5＇-triphosphate inhibitor, as well as caffeine （20 mmol/L）, a ryanodine receptor agonist, triggered [Ca^2＋]i increase in small trigeminal ganglion neurons. A similar response was induced by application of adenosine 5＇-triphosphate （100 μmol/L）. In Ca^2＋-free conditions, adenosine 5＇-triphosphate-induced [Ca^2＋]i transients in small trigeminal ganglion neurons were inhibited in cells pre-treated with thapsigargin （P 〈 0.01）, but not by caffeine （P 〉 0.05）. In normal, extracellular solution, adenosine 5＇-triphosphate-induced [Ca^2＋]i transients in small trigeminal ganglion neurons were partly inhibited in cells pre-treated with thapsigargin （P 〈 0.05）. CONCLUSION： Inositol-1,4, 5-triphosphate （IP3）- and ryanodine-sensitive Ca^2＋ stores exist in rat nociceptive trigeminal ganglion neurons. Two pathways are involved in the purinoreceptor-mediated [Ca^2＋]i rise observed in nociceptive trigeminal ganglion neurons. One pathway involves the metabotropic P2Y receptors, which are associated with the IP3 sensitive Ca^2＋store, and the second pathway is coupled to ionotropic P2X receptors that induce the Ca^2＋ influx.