长江地区汉族人群红细胞EsD和PGM1的分布

采用琼脂糖、水解淀粉混合凝胶电泳法同时分析人血工细胞酯酶Ｄ和磷酸葡萄变位酶Ｉ二种酶型，调查了该二种酶的表型分布和基因频率及其识别能力，并与不同地区，不同国家和不同民族进行比较。此法可用于个人识别和亲权鉴定。     

血管紧张素转换酶的固相化与性质

目的为从天然肽类混合物中分离血管紧张素转换酶（ angiotensin converting enzyme, ACE）抑制活性物质,对固相化 ACE（固相酶）进行研究。方法在低水活度条件下利用苯甲磺酰氯活化 Sepharose CL- 4B凝胶侧链基团上的羟基,形成高反应活性的苯磺酰基团,通过与 ACE上的氨基反应将酶固定于琼脂糖凝胶。结果固相化 ACE的反应 pH范围较宽,最适反应 pH比溶液酶（自由酶）增加 0.6个单位,达到 8.8。分别在 pH9.0和 pH6.5条件下处理 24 h,固相酶活力保留 82％和 68％,溶液酶只剩下 64％和 39％。两种酶均在 50℃左右活力最大,温度继续升高溶液酶迅速失活。分别在 40℃和 50℃处理 2 h,固相酶剩余活力为 82％和 34％,溶液酶为 52％和完全失活。 20℃放置 1个月,固相酶剩余活力为 61％,而溶液酶只有 20％。结论 ACE固相酶在 pH和温度稳定性方面强于溶液酶。     

急性胰腺炎腺泡细胞内胰酶激活机制的探讨

采用缺乏胆碱的乙硫氨酸饮食喂养幼年雌鼠诱发急性坏死性胰腺炎时，胰组织蛋白含量及淀粉酶活性升高，胰腺腺泡细胞内酶原颗粒大量积聚，胰管内均质性分泌物明显减少，表明急性胰腺炎时腺泡细胞对酶原颗粒的细胞外放作用受到抑制。腺泡细胞内大量空泡形成，通过噬分泌作用，发生酶原颗粒和溶酶体或空泡间膜融合，致使溶酶体酶对胰酶原发生水解，导致胰酶干腺泡细胞内被激活，从而引起胰腺自身消化。     

蒜酶催化蒜氨酸动力学研究

目的:研究酶促反应的动力学参数,为新药设计提供依据。方法:采用HPLC方法测定酶促反应的动力学参数及蒜酶的最适pH和最适温度。结果:蒜酶以蒜氮酸为底物,最大反应速度Vmax=27.9 μnml·min-1·mg-1,米氏常数Km=3.6 mmol/L,其最适pH为6.6,最适温度为35℃。结论:酶促反应的动力学参数为蒜酶寻求有利的反应条件、更大限度地提高酶反应的效率提供了参考数据。     

微量元素与酶

微量元素与酶塞冬（老年医学教研室）酶是一种具有特殊催化功能的特殊蛋白质，是＂生物催化剂＂，也就是由活的生物细胞产生的，可在细胞内或外起催化活性的蛋白质。生物的代谢过程都是酶作用引起的化学反应，在生物体内，极少有不需要酶参加而自发进行的化学反应。酶具有...     

急性胰腺炎—酶与抗酶体系

急性胰腺炎(AP)发病机制的研究已经提出梗阻分泌学说、共同通道学说、十二指肠返流学说、逆向弥散学说、胰酶细胞内激活学说和胰微循环障碍学说。而胰酶自身消化是连结众多学说的最后公路,这已得到广泛认可。近年来围绕此观点不仅对胰酶进行了更深入的研究,且对机体防御体系亦有相当的了解。本文拟简述有关胰酶、胰管粘膜屏障及体液抗酶体系等几个问题。 1 胰酶及其在急性胰腺炎中的意义胰腺外分泌可分泌消化三大食物的众多酶     

血清酶在模拟高原条件下的活力变化

本文观察平原和模拟3500m、4500m高原低压实验舱内11名健康男性血清酶CK、LDH、HBDH、AST的活力变化。结果表明酶活力随海拔升高而增高,其显著性顺序为CK、LDH、HBDH,而AST则无统计学意义。CK与LDH比值和心率与海拔增高呈一致的量-效改变,与血氧饱和度和劳动负荷值呈相反的量-效变化;复合锻炼可改善血清酶变化程度恢复至近似平原水平。提示CK和LDH可作为评估人对高原低氧环境的适应能力较好指标。     

小牛肠碱性磷酸酶激活与抑制的动力学观察

应用磷酸苯二钠法观察了某些羟基化合物、氨基酸对小牛肠碱性磷酸酶（ＥＣ３．１．３．１）活力的影响。     

释炎达肠溶片中锯齿酶活力测定的方法学研究

本文建立了释炎达肠溶片中锯齿酶活力测定方法。最适反应条件：１６．０μｇ／ｍｌ Ｌ－酷氨酸溶液为标准对照；０．６％酪蛋白溶液为底物；１．８％三氯醋酸溶液为沉淀剂；反应时间为２０分钟；反应温度为（３７±０．５）℃。结果准确，ＲＳＤ〈３．０％。本法操作简便、快速，适用于释炎达片的质量控制。     

α2巨球蛋白抑制蕲蛇毒激活兔血小板的实验观察

An in vitro study of alpha 2-mengaloglobulin (alpha 2MG) in the inhibition of the activation of washed rabbit platelet by Chinese Agkistrodon acutus venom (CAAV) was reported. Results showed that CAAV induced aggregation rate of washed rabbit platelet was positively related to the CAAV concentration, and the maximal aggregation rate was 43.8 +/- 9.9% at the concentration of 100 micrograms/ml. Meanwhile the release of serotonin (5-HT) and platelet factor 4(PF4) from the platelet reached maximum at the CAAV concentrations of 0.81 +/- 0.07 microgram/ml and 39.08 +/- 2.78%, respectively. Platelet aggregation and the release of 5-HT and PF4 induced by CAAV could be inhibited by the addition of 0.25% alpha 2 MG into the platelets both 1 minute before and 1 minute after the addition of CAAV. When alpha 2 MG was added to the platelets 1 minute prior to the addition of CAAV, the platelet aggregation and the ultrastructural changes which could be induced by CAAV were not observed, and the morphology of the rabbit platelets was the same as that of the normal counterparts.     

PKC和TPK在血小板激活中的作用

目的为了研究蛋白激酶（PKC）和酪氨酸蛋白激酶（TPK）在血小板激活中的作用。方法用卟啉酸肉豆蔻乙酸酯（PMA）,凝血酶,前列腺素E1（PGE1）和环磷酸腺苷（db－cAMP）,在含二磷酸腺苷（ADP）清除剂的缓冲剂中去激发经阿司匹林切断,32P－NaH2PO4标记冲洗后的牛血小板。40KD（PKC的底物）的磷酸化程度随PMA或凝血酶的浓度而增加。同样26KD、38KD的磷酸也是如此。由于PMA诱导的血小板聚集的同时伴随PKC活化。PGE（腺苷环化酶激活物）不能抑制由50nmol/1PMA诱导的血小板聚集,db-cAMP,腺苷不能抑制PKC引起的蛋白磷酸化。结果在碱处理的聚丙烯酰胺凝胶电泳（PAGEgel）中发现40KD和57KD多肽比其他多肽更有抗碱力。40KD和57KD多肽的磷酸氨基酸分析指出含有磷酸丝氨酸、磷酸苏氨酸和磷酸酪氨酸。结论在PMA、凝血酶激活的血小板中,PKC、TPK都发生激活作用,40KD废物是PKC的底物又是TPK的底物,PKC和TPK在血小板聚集中起着重要调节作用。     

刺激型抗人血板McAb对人血小板细胞骨架蛋白的影响

The effects of monoclonal antibodies HIP2, APT4 and HI117 on the platelet cytoskeleton were investigated. The results showed that HIP2, APT4 and HI117 could induce an increase of platelet cytoskeleton materials in PRP. The action of HIP2 and APT4 could be obviously inhibited by the calmodulin inhibitor EBB. The inhibition rates of EBB were 76.3% and 48.95%, respectively. But EBB couldn't inhibit the HI117-induced an increase of platelet cytoskeleton materials. EBB could completely inhibit APT4-induced platelet aggregation(100%) and partially inhibit HIP2-induced platelet aggregation (14.26%). It couldn't inhibit HI117-induced platelet aggregation. These McAbs couldn't induce aggregation and actin mobilization in washed platelets in the presence of EDTA. The results indicate that platelet aggregation and the increase of actin induced by these McAbs, in addition to Ca2+, could be related to a factor or factors in the plasma. The Ca(2+)-CM system might play an important role in platelet aggregation and actin mobilization induced by HIP2 and APT4.     

PRT318对胶原诱导人血小板Syk磷酸化的影响

摘要：目的  观察脾酪氨酸激酶（Syk）抑制剂PRT060318（PRT318）在体外对人血小板聚集率及Syk磷酸化的影响。方法  采用比浊法测定PRT318对胶原、二磷酸腺苷（ADP）及花生四烯酸（AA）诱导的人血小板聚集率的影响;运用Western blot检测Syk525/6磷酸化水平。结果  Syk特异性抑制剂PRT318可抑制胶原诱导的人血小板聚集率,但对ADP或AA诱导的人血小板聚集率无影响。在蛋白水平上PRT318可促进人血小板在胶原诱导下Syk525/6磷酸化水平升高。酪氨酸蛋白激酶抑制剂PP2可抑制胶原诱导的人血小板聚集,降低人血小板在胶原诱导下Syk525/6磷酸化水平,并可阻断胶原诱导下PRT318促Syk525/6磷酸化作用。结论  PRT 318对胶原诱导的血小板聚集具有抑制作用,并能促进胶原诱导的血小板膜受体糖蛋白VI信号通路上Syk525/6磷酸化,提示PRT318可能通过作用于Syk525/6磷酸化而抑制血小板聚集。

     

毛葡萄叶水提物抑制血小板聚集的初步研究

目的探讨毛葡萄叶水提物（Gx）对血小板聚集的影响。方法分离健康人的血小板,与不同生药浓度的Gx于37℃孵育10 min后,检测胶原（collagen）和凝血酶（thrombin）诱导的人血小板聚集的变化。小鼠腹腔注射Gx后,分离小鼠血小板,检测二磷酸腺苷（ADP）诱导的血小板聚集的变化。结果 Gx对2μg/ml collagen诱导的血小板聚集有显著抑制作用（P〈0.05）,且呈现Gx的剂量依赖性（P〈0.05）;只有0.01 mg/ml的Gx对0.1 U/mlthrombin诱导的血小板聚集有抑制作用,且不呈现Gx的剂量依赖性。同时,Gx可抑制ADP诱导的腹腔注射Gx的小鼠血小板聚集,且呈现ADP剂量依赖性。结论 Gx具有明显抗血小板聚集作用,为开发抗血栓药物提供了实验依据。     

Effect of Aqueous Extracts of Several Kinds of Herbs on Human Platelet Aggregation and Expression of P-Selectin in Vitro

Objective: To study the effect of aqueous extract of several kinds of herbs on human platelet aggregation and expression of P-selectin in vitro. Methods: Blood was collected from volunteers. Effects of the prepared water extracts of herbs on platelet aggregation were monitored on a Packs-4 aggregometer. The fluorescence intensity of water extracts of Caulis Spatholobi, Flos Carthami and Rhizoma Curcumae on the expression of P-selectin in human platelets of healthy persons was measured with flow cytometry. Results: Out of several herbs investigated, Flos Carthami and Rhizoma Curcumae potently inhibited platelet aggregation after incubation with platelet-rich plasma (PRP) for 15 min. Caulis Spatholobi, Flos Carthami and Rhizoma Curcumae inhibited adenosine-5''-diphosphate (ADP) or platelet activating factor (PAF)-induced platelet aggregation in PRP in a dose-dependent manner. In contrast to Flos Carthami and Rhizoma Curcumae, Caulis Spatholobi could not inhibit thrombin-induced platelet aggregation. Despite its inability to inhibit thrombin-induced platelet aggregation in PRP, Caulis Spatholobi had a greater anti-aggregating activity in PRP induced by ADP or PAF. Caulis Spatholobi and Flos Carthami showed significant inhibitory effects on the expression of P-selectin. Conclusions: Caulis Spatholobi, Flos Carthami and Rhizoma Curcumae have potent anti-platelet properties, and their inhibitory actions are mediated via different mechanisms. Caulis Spatholobi inhibited ADP-induced platelet aggregation but not by thrombin, indicating that its mechanism of action might be independent of the thromboxane pathway. The effect of Caulis Spatholobi and Flos Carthami were associated with suppressing the expression of P-selectin.     

THE IMPAIRMENT OF PLATELET FUNCTION IN FIBRINOLYSIS AND PRESERVING EFFECT OF APROTININ

Platelet adhesion depends on the platelet membrane glycoprotein Ib (GPIb) and plasma von Willebrand Factor (vWF), which can be reflected by ristocetin-induced aggregation. Here we report damage effect of fibrinolysis and preserving effect of aprotinin on platelet function. Addition of 40 U/ml urokinase and 0.3 U/ml plasmin to PRP or washed platelets made the ristocetin-induced aggregation decline to 31.6% and 38.5% of control value respectively. The extent of declining was positively correlated with the concentration of urokinase and plasmin. Meanwhile, the platelet GPIb decreased to 76.4% of control value. The results showed that the fibrinolysis impaired the platelet function and this effect may be associated with the hydrolysis of GPIb. Further research found that by adding the same dose of urokinase or plasmin to aprotinin-pretreated PRP or washed platelets, the aggregation did not change statistically and decrement of GPIb is much less marked. We concluded that the aprotinin could relieve the platelet dsfunction effectively by its inhibitory effect on fibrinolytic activity.     

Lysophosphatidic acid is the unique platelet-activating substance in human malignant ascites

Pathological blood platelet activation promotes thrombosis in cancer patients, but the specific substances involved are still under investigation. Tumor exudates have been described to contain lysophosphatidic acid (LPA), a known platelet-activating substance, and the concentration of mediators present in malignant ascites are constantly equilibrated with the concentration in plasma. We hypothesized that the ascites of cancer patients might activate platelets, and that this may be caused by LPA. Indeed, ascites samples from 15 different patients with cancer induced shape change and an increase of cytosolic Ca2+ of isolated platelets; both responses were cross-desensitized by lysophosphatidic acid (LPA), but not by other platelet stimuli. Moreover shape change, Ca2+ mobilization and aggregation induced by ascites could be completely blocked by pretreatment of platelets with specific LPA-receptor antagonists. Phospholipids were extracted from ascites, separated by thin layer chromatography, and individual fractions were tested for activity on platelets. The platelet activating substance co-migrated with LPA, whereas other fractions were inactive. Notably, ascites induced through LPA-receptor activation platelet aggregation in whole blood. Our results suggest that LPA plays an essential role in the pathological platelet activation in cancer patients. We propose that LPA receptor antagonists could be effective in blocking cancer-associated platelet activation and thus preventing thrombosis.     

EFFECT OF 764－3 ON AGGREGATION AND CALCIUM MOVEMENTS IN AEQUORIN－LOADED HUMAN PLATELETS

ＥＦＦＥＣＴＯＦ７６４－３ＯＮＡＧＧＲＥＧＡＴＩＯＮＡＮＤＣＡＬＣＩＵＭＭＯＶＥＭＥＮＴＳＩＮＡＥＱＵＯＲＩＮ－ＬＯＡＤＥＤＨＵＭＡＮＰＬＡＴＥＬＥＴＳＷｕＨｕａｉｚｈｕ武怀珠；ＬｉＪｉａｚｅｎｇ李家增；ＰｅｎｇＬｉｎ彭林；ＴｅｎｇＢｉｎ滕彬ａｎｄＺ...     

脂筏干扰剂甲基-β-环糊精对血小板活化和聚集的影响

目的: 探讨脂筏干扰剂甲基-β-环糊精(MβCD)在体外对血小板活化和聚集的影响。方法: 采静脉全血静止20min后加二磷酸腺苷(ADP)20μmol/L刺激10min,或预先用MβCD(10mmol/L)处理后再加ADP刺激;同时设立未加ADP为实验对照组。用流式细胞术检测血小板中表达膜表面活化纤维蛋白原受体(FIB-R)阳性比例及其平均荧光强度(MFI)和血小板聚集率。结果: ADP刺激组血小板中FIB-R阳性比例(%)、FIB-R (MFI)和血小板聚集率(%)分别为75.93±10.27、329.19±121.72和23.03±4.96,实验对照组则分别为66.66±12.58、73.78±21.91和2.53±0.72,其中后两种指标差异有统计学意义(P<0.01)。MβCD预处理加ADP刺激组的三项指标均比ADP刺激组显著降低(P<0.01)。结论: 具有转移细胞膜胆固醇的MβCD在体外能显著抑制ADP诱导的血小板活化和聚集。