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1.
Sun W  Wen YY  Wu GY 《生理学报》1998,50(1):82-86
本文比较了正常和高血压大鼠不同动脉血管肌球蛋白轻链激酶(MLCK)和依赖Ca^2+的钙调素磷酸酶(Ca^2+/CaM-PP)活性的变化。结果表明:在自发性高血压大鼠(SHR)不同血管MLCK的活性不同,依次为主动脉(A)〉尾动脉(CA)〉肠系膜动脉(MA);而在WKY大鼠,该酶在不同血管的活性依次为A〈〈CA〈〈AM。在WKY大鼠,MA Ca^2+/CaM-PP活性明显高于SHR。在肾性高血压大鼠  相似文献   

2.
肌球蛋白轻链激酶及其抑制剂   总被引:2,自引:0,他引:2  
杨桂芝 《生命的化学》1999,19(6):279-281
肌球蛋白轻链激酶(MLCK)是三磷酸肌醇(IP3)、Ca2+-钙调蛋白(CaM)信息转导途径的一种重要蛋白质,也是第一个被发现的依赖于CaM的激酶,对肌肉收缩起着重要作用[1]。MLCK抑制剂从CaM水平或MLCK自身水平上抑制MLCK的活性,可抑制或减弱平滑肌的收缩。天然植物中的多种化合物对MLCK有较强的抑制作用,有吖啶类、黄酮类、蒽醌类、菲类和喹啉类化合物等,为植物资源的开发利用提供了有价值的依据。1.MLCK的结构和酶促反应动力学研究MLCK的活性型是由Ca2+、CaM和全酶组成的三元复…  相似文献   

3.
小鼠早期胎在6℃不同贮液中的保存研究   总被引:2,自引:1,他引:1  
低温能抑制哺乳动物植入前胚胎的代谢和发育,从而可使胚胎在体外进行短期贮存。本文利用三种不同贮存液:Wthitten's,PBS和CMRL-1066对小鼠2-和8-细胞胚胎进行贮存研究。结果表明,贮于上述三种贮液中的小鼠2-细胞胚胎,在6℃贮24小时后,经37℃培养,成活率分别为42.8%、0%和0%;贮72小时后的8-细胞胚胎的成活率分别为43.3%、20.0%和0%。还证实,培养液中丙酮酸钠和乳  相似文献   

4.
流感病毒感染诱导MDCK细胞调亡的研究   总被引:2,自引:0,他引:2  
用荧光染色、DNA凝胶电泳等方法检测了A型流感病毒株A1/京防86-1和B型流感病毒株B/沪防93-1诱导狗肾传代细胞(MDCKcells)的凋亡情况,并采用MTT法和流式细胞仪比较了这2株病毒对MDCK细胞毒力和调亡诱导能力水平。结果显示:病毒感染6h后,细胞DNA发生断裂,病毒感染12h后,可见明显的染色质凝聚;在一定范围内,细胞调亡强度表现出明显的时间和剂量依赖关系;并且,A型流感病毒株的毒  相似文献   

5.
本文用荧光标记的受体底物〔Gnβ1-2Mα1-6(Gnβ1-2Mα1-3)Mβ1-4Gnβ1-4(Fucα1-6)Gn-PA〕,结合高效液相层析(HPLC)建立了细胞表面β1-4半乳糖基转移酶的活性检测方法。用这种方法研究HL60细胞,发现不同的培养时间,其细胞表面的酶变化明显,在24小时酶活性最高,此时细胞处在分裂间期。用佛波酯(PMA),视黄酸(RA)等细胞诱导分化剂处理HL60细胞株时,发现其表面活性发生了明显的变化,PMA诱导的细胞其表面酶活性在24小时变化最大,升高到对照的1.3倍;而RA处理的细胞其表面酶活性在72小时变化最大,升高到对照的1.72倍。  相似文献   

6.
低温能抑制哺乳动物植入前胚胎的代谢和发育,从而可使胚胎在体外进行短期贮存。本文利用三种不同贮存液:Whitten′s、PBS和CMRL-1066对小鼠2-和8-细胞胚胎进行贮存研究。结果表明,贮于上述三种贮液中的小鼠2-细胞胚胎,在6℃贮24小时后,经37℃培养,成活率分别为42.8%、0%和0%;贮72小时后的8-细胞胚胎的成活率分别为43.3%、20.0%和0%。还证实,培养液中丙酮酸钠和乳酸钠的存在对小鼠胚胎的体外发育是至关重要的。  相似文献   

7.
血管再狭窄发生过程中MMP-2基因表达与胶原转换的动态变化   总被引:18,自引:0,他引:18  
建立主动脉内皮剥脱后血管再狭窄大鼠模型,用Northern 印迹分析、含明胶SDS-PAGE、羟脯氨酸含量测定及流式细胞术动态观察血管再狭窄发生过程中MMP-2基因表达与胶原转换及血管细胞增殖之间的关系.实验结果表明,血管内皮剥脱后,MMP-2基因表达被显著诱导,MMP-2活性及胶原转换明显增高,在第7 d,MMP-2表达活性及胶原合成与降解均达到峰值;第21 d,MMP-2表达恢复正常,胶原合成和降解仍维持在较高水平.流式细胞分析结果显示,血管内皮剥脱后进入增殖状态及发生凋亡的细胞显著增加,增殖细胞所占比例高于凋亡细胞,且两者均随内皮损伤后的时间延长而增加.  相似文献   

8.
平滑肌收缩中Ca^2+敏感性调节的机理   总被引:4,自引:0,他引:4  
Zhu WZ  Han QD 《生理科学进展》1997,28(3):243-245
多种激动剂增加细胞器对Ca^2+的敏感性,即Ca^2+的敏感性,即Ca^2+敏感化作用。激动剂的这种作用可能是通过G蛋白,经信号分子花生四烯酸和二酰基甘油,反暹号传递到肌球蛋白轻链磷酸酶(MLCP),增加肌球蛋白磷酸化。细胞内游离Ca^2+升高到一定程度,calmodulin激酶Ⅱ活化,导致MLCK磷酸化,降低了其对Ca^2+-calmodulin亲和力,MLCK对Ca^2+敏感性降低,即Ca^2  相似文献   

9.
鸡平滑肌肌球蛋白轻链激酶在NIH 3T3细胞中的表达   总被引:2,自引:0,他引:2  
肌球蛋白轻链激酶(MLCK)在调节平骨肌细胞收缩过程中具有十分重要的作用。本言语通过将MLCKcDNA插到质粒pBKrsv中构建pBKrsv-MLCK,并转染至NIH3T3细胞中,DNA-PCR、RT-PCR和Western blot分析表达转染细胞可表达MLCK。活生分析表明所表达的MLCK具有生物学活性。为进一步研究MLCK在信号传导,调节平骨肌收缩等作用奠定了基础。  相似文献   

10.
杏仁核内注射CCK—8抑制胃运动的机制   总被引:3,自引:0,他引:3  
唐明  苏海灵 《生理学报》1997,49(5):569-574
应用脑核团内微量注射和核团电刺激方法,观察杏仁基底内侧(BMA)对胃运动的影响,分析BMA与下丘脑腹内侧核(VMH)的机能联系。结果如下:(1)双侧BMA内注射八肽胆囊收缩素(CCK-8)(50ng/lμl),出现胃内压(IGP)和胃运动频率(GMF)显著下降(P〈0.01)。(2)BMA内注射CCK-A受体阻断剂[L364,718](100ng/lμl)或CCK-B受体阻断剂[L365,260]  相似文献   

11.
目的:观察磷酸肌酸钠对重度颅脑损伤合并心肌损害患者的心肌、脑组织保护作用.方法:选择60例重度颅脑损伤合并心肌损害需要手术治疗的患者随机分为治疗组30例,对照组30例,对照组采用常规治疗,治疗组加用磷酸肌酸钠至术后3天,观察两组颅内压(ICP),脑氧分压(PbrO2),心功能及心肌酶的变化情况.结果:治疗组颅内压及心肌酶明显低于对照组(P<0.05),治疗组脑氧分压心功能明显优于对照组(P<0.05).结论:应用磷酸肌酸钠可明显改善心脑组织微循环及能量代谢,具有良好的保护作用.  相似文献   

12.
目的:观察磷酸肌酸钠注射液治疗≧80 岁高龄多病因心力衰竭患者的疗效。方法:≧80 岁高龄多病因心力衰竭患者115 例,随机分为治疗组58 例,对照组57 例。对照组给予常规抗心衰治疗,治疗组在此基础上加用磷酸肌酸钠注射液,观察两组治疗 前后NYHA心功能分级、血浆NT-proBNP 水平,磷酸肌酸钠注射液相关不良反应发生率并监测治疗前后的肝肾功能等指标。结 果:治疗5 天后治疗组总有效率显著高于对照组(P<0.05),血浆NT-proBNP 含量显著低于对照组(P<0.05),需加用洋地黄类强心 药物的患者人数显著低于对照组(P<0.05);治疗14天后两组各指标均有显著改善,总有效率、血浆NT-proBNP 下降幅度无明显 区别。结论:常规抗心衰治疗基础上加用磷酸肌酸钠注射液能够更快改善≧80 岁高龄多病因心力衰竭患者症状,安全有效。  相似文献   

13.
Deminice R  Jordao AA 《Amino acids》2012,43(2):709-715
The objective of this study was to evaluate the effect of creatine supplementation on muscle and plasma markers of oxidative stress after acute aerobic exercise. A total of 64 Wistar rats were divided into two groups: control group (n = 32) and creatine-supplemented group (n = 32). Creatine supplementation consisted of the addition of 2% creatine monohydrate to the diet. After 28 days, the rats performed an acute moderate aerobic exercise bout (1-h swimming with 4% of total body weight load). The animals were killed before (pre) and at 0, 2 and 6 h (n = 8) after acute exercise. As expected, plasma and total muscle creatine concentrations were significantly higher (P < 0.05) in the creatine-supplemented group compared to control. Acute exercise increased plasma thiobarbituric acid reactive species (TBARS) and total lipid hydroperoxide. The same was observed in the soleus and gastrocnemius muscles. Creatine supplementation decreased these markers in plasma (TBARS: pre 6%, 0 h 25%, 2 h 27% and 6 h 20%; plasma total lipid hydroperoxide: pre 38%, 0 h 24%, 2 h 12% and 6 h 20%, % decrease). Also, acute exercise decreased the GSH/GSSG ratio in soleus muscle, which was prevented by creatine supplementation (soleus: pre 8%, 0 h 29%, 2 h 30% and 6 h 44%, % prevention). The results show that creatine supplementation inhibits increased oxidative stress markers in plasma and muscle induced by acute exercise.  相似文献   

14.
The objective of this study was to evaluate the effect of a PGF2α-analogue (PGF) on ovulation and pregnancy rates after timed artificial insemination (TAI) in cattle. In experiment 1, crossbred dual-purpose heifers, in a crossover design (3 × 3), were given an intravaginal progesterone-releasing insert (controlled internal drug release [CIDR]) plus 1 mg estradiol benzoate (EB) intramuscularly (im) and 250 μg of a PGF-analogue im on Day 0. The CIDR inserts were removed 5 days after follicular wave emergence, and the heifers were randomly divided into three treatment groups to receive the following treatments: (1) 1 mg of EB im (EB group, n = 13); (2) 500 μg of PGF im (PG group, n = 13); or (3) saline (control group, n = 13), 24 hours after CIDR removal. Ovulation occurred earlier in EB (69.81 ± 3.23 hours) and PG groups (73.09 ± 3.23 hours) compared with control (83.07 ± 4.6 hours; P = 0.01) after CIDR removal. In experiment 2, pubertal beef heifers (n = 444), 12 to 14 months of age were used. On Day 0, the heifers were given a CIDR insert plus 2 mg EB im. On Day 9, the CIDR was removed and the heifers were given 500 μg of PGF im. Heifers were randomly assigned into one of three treatment groups: (1) 1 mg of EB (EB group; n = 145); (2) 500 μg of PGF (PG group; n = 149), both 24 hours after CIDR removal; or (3) 600 μg of estradiol cypionate (ECP group; n = 150) at CIDR removal. Timed artificial insemination occurred 48 hours after CIDR removal in the ECP group and 54 hours in the PG and EB groups. The percentage of heifers ovulating was higher in the PG group compared with the other groups (P = 0.08). However, the pregnancy rates did not differ among groups (47.6%, 45%, and 46.6%, for EB, PG, and ECP, respectively; P = 0.9). In experiment 3, 224 lactating beef cows, 40 to 50 days postpartum with 2.5 to 3.5 of body condition score were treated similarly as described in experiment 2, except for the ECP group, which was excluded. The treatments were as follows: 1 mg EB (EB group; n = 117) or 500 μg PGF (PG group; n = 107), 24 hours after CIDR removal. The calves were temporarily separated from their dams from Days 9 to 11. No difference was detected on the pregnancy rate between the EB and PG groups (58.1% vs. 47.6%, respectively; P = 0.11). Taken together, the combined results suggested that PGF2α could be successfully used to induce and synchronize ovulation in cattle undergoing TAI, with similar pregnancy rates when compared with other ovulatory stimuli (ECP and EB).  相似文献   

15.
It is well established that severe hypertrophy induces metabolic and structural changes in the heart which result in enhanced susceptibility to ischemic damage during cardioplegic arrest while much less is known about the effect of cardioplegic arrest on moderately hypertrophied hearts. The aim of this study was to elucidate the differences in myocardial high energy phosphate metabolism and in functional recovery after cardioplegic arrest and ischemia in mildly hypertrophied hearts, before any metabolic alterations could be shown under baseline conditions.Cardiac hypertrophy was induced in rats by constriction of the abdominal aorta resulting in 20% increase in heart weight/body weight ratio (hypertrophy group) while sham operated animals served as control. In both groups, isolated hearts were perfused under normoxic conditions for 40 min followed by infusion of St.Thomas' Hospital No. 1 cardioplegia and 90 min ischemia at 25øC with infusions of cardioplegia every 30 min. The changes in ATP, phosphocreatine (PCr) and inorganic phosphate (Pi) were followed by31 P nuclear magnetic resonance (NMR) spectroscopy. Systolic and diastolic function was assessed with an intraventricular balloon before and after ischemia.Baseline concentrations of PCr, ATP and Pi as well as coronary flow and cardiac function were not different between the two groups. However, after cardioplegic arrest PCr concentration increased to 61.8 ± 4.9 mol/g dry wt in the control group and to 46.3 ± 2.8 mol/g in hypertrophied hearts. Subsequently PCr, pH and ATP decreased gradually, concomitant with an accumulation of Pi in both groups. PCr was transiently restored during each infusion of cardioplegic solution while Pi decreased. PCr decreased faster after cardioplegic infusions in hypertrophied hearts. The most significant difference was observed during reperfusion: PCr recovered to its pre-ischemic levels within 2 min following restoration of coronary flow in the control group while similar recovery was observed after 4 min in the hypertrophied hearts. A greater deterioration of diastolic function was observed in hypertrophied hearts.Moderate hypertrophy, despite absence of metabolic changes under baseline conditions could lead to enhanced functional deterioration after cardioplegic arrest and ischemia. Impaired energy metabolism resulting in accelerated high energy phosphate depletion during ischemia and delayed recovery of energy equilibrium after cardioplegic arrest observed in hypertrophied hearts could be one of the underlying mechanisms.  相似文献   

16.
Summary The importance of time of fertiliser-soil contact, distance of phosphate movement from fertiliser and phosphate fertiliser solubility in determining the availability of phosphate to the early growth of lowland rice was investigated. Phosphate availability was measured by phosphate uptake in a glass-house experiment in which two week old rice seedlings were transferred to the surface of fertiliser-treated soils for three weeks before harvesting. The fertilisers used in the study were monoammonium phosphate (MAP), ammonium polyphospate (APP), superphosphate (SP) and rock phosphate (RP). Availability of all fertilisers was tested in this way after 2, 4 and 8 weeks of fertiliser-soil contact. In an associated laboratory experiment the distance of phosphate movement and fertiliser solubility (as measured by quantity of phosphate that had moved away from the fertilizer source) was determined at 2 and 4 weeks in glass tubes containing waterlogged soil. The results showed that at all times of measurement, the availability of the fertilisers could be ranked MAP>APP≥SP>RP. Of the 6 possible correlations between phosphate uptake and phosphate movement, only one was significant for the fertiliser-soil contact period of 2 weeks and phosphate movement at 4 weeks, (r=0.950, P<0.05). Of the 6 possible correlations between phosphate uptake and fertiliser solubility, none were significant. However, of the 6 possible correlations between phosphate uptake and the product of the two laboratory parameters (referred to as the availability index) four were significant (P<0.05 in all cases), and involved only the fertiliser-soil contact periods of 2 and 4 weeks. These results indicate that fertiliser solubility alone is not a satisfactory correlative determinant of availability of fertiliser phosphate to lowland rice. Phosphate movement alone is marginally better, but the best correlations are obtained when both parameters are taken into account. While their combined effects are evident only during the first four weeks after fertiliser application, this may still be important to the successful establishement of a rice crop.  相似文献   

17.
缺血预处理对缺血再灌注后兔脊髓磷酸腺苷代谢的影响   总被引:5,自引:0,他引:5  
目的:研究缺血参处理对缺血再灌注后兔脊髓磷酸腺苷代谢的影响。方法:往置入腹主动脉的Swan-Ganz导管气囊内注气造成兔腰髓缺血模型。将实验兔分为假手术组、缺血组和预处理组。应用反相高效液相色谱方法(reverse phase HPLC),对缺血再灌注后不同时间点腰髓组织中磷酸腺苷(ATP、ADP、AMP)的含量进行检测。结果:和假手术组相比,缺血组兔再灌后各时间点腰髓组织ATP含量有明显下降(P<0.01)。与缺血组相应时间点相比,预处理组兔再灌注后腰髓组织ATP含量明显提高(P<0.01)。结论:缺血预处理显著提高缺血再灌注后兔脊髓组织ATP含量,这可能是缺血预处理对脊髓缺血再灌注损伤产生保护作用的机制之一。  相似文献   

18.
Magnesium-diltiazem cardioplegia was evaluated in the intact, perfused rat heart to determine whether the joint administration of these agents would adversely affect myocardial contractile and high-energy phosphate recovery following intermittent, normothermic global ischemic arrest. Sequential metabolic and functional analyses were performed on isolated perfused rat hearts during each phase of the experimental protocol: control (10 min), normoxic cardioplegia (10 min), intermittent global ischemic arrest (two 15-min periods separated by 2 min infusion of the normoxic cardioplegic perfusate), and normoxic postischemic control reperfusion (60 min). Four different cardioplegic solutions were evaluated: 30 mM KCl, 30 mM KCl with 2 mg diltiazem/liter, 20 mM MgCl2, and 20 mM MgCl2 with 2 mg diltiazem/liter. Myocardial phosphatic metabolite levels and intracellular pH were analyzed nondestructively in the intact hearts by phosphorus-31 NMR spectroscopy. Corresponding measurements of peak left intraventricular pressure, rate of peak pressure development (dP/dt), and contraction frequency were performed at the midpoint during each 5-min interval of 31P NMR signal averaging. Magnesium plus diltiazem-treated hearts were distinguished from all other groups by a marked delay in postischemic functional recovery consisting of a prolonged depression in contractility (34% of control, P less than 0.01) that persisted throughout the first 50 min of postischemic reperfusion. Diltiazem in combination with magnesium cardioplegia was detrimental to postischemic functional recovery, despite a rapid restoration of high-energy phosphate stores. The apparent adverse interactive effects of excess magnesium and diltiazem suggest that elective ischemic arrest with magnesium cardioplegia in combination with diltiazem may be contraindicated clinically. The mechanistic basis and drug specificity of this response require further clarification. The present findings appear to exclude ATP and PCr production, and structural causes as the basis for the observed aberrant functional recovery from global ischemia of magnesium plus diltiazem-arrested hearts.  相似文献   

19.
Wilson AM  Harris GA 《Plant physiology》1966,41(9):1416-1419
Net synthesis of phosphate esters was measured in crested wheatgrass seeds [Agropyron desertorum (Fisch.) Schult.] to learn what phosphorylating reactions occur in early stages of germination. Phosphate esters were separated on ion exchange columns and identified by cochromatography and chemical analyses. Synthesis of adenosine triphosphate and UDP-hexose was detected 6 hours after the beginning of water absorption. This synthesis occurred during the period of rapid increase in water potential. Synthesis of hexose phosphate and uridine triphosphate was detected 12 hours after the beginning of water absorption. The concentrations of these esters increased during 48 hours. Increases in concentration of inositol di-, tri-, and tetraphosphate suggested that hydrolysis of inositol hexaphosphate began after 12 hours.  相似文献   

20.
目的:探讨放疗联合热疗治疗晚期卵巢癌术后复发的临床疗效。方法:选择哈医科大学第四临床医院及黑龙江省第二肿瘤医院2010年3月~2013年3月收治的68例卵巢癌术后复发患者(均为术后化疗6-8个疗程盆腔复发),将其随机分为热疗联合放疗组(实验组)和单纯化疗组(对照组)。所有患者均给予化疗6-8个周期以上,实验组在放疗结束后2小时内进行热疗,2次/周,共6-8周。通过影像学检查治疗前后肿瘤体积的变化进行疗效评估,观察两组治疗期间各种不良反应的发生情况及术后3年的生存情况。结果:观察组肿瘤完全缓解率(CR)实验组明显高于对照组(P0.05)。皮肤损伤的发生率显著高于对照组,而白细胞计数下降的发生率明显低于对照组(P0.05)。两组随访1、2年的生存率无明显差异(P0.05),实验组第3年的生存率明显高于对照组(P0.05)。结论:热疗联合放疗可提高晚期卵巢癌术后复发的临床疗效。  相似文献   

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