MAPKs represent novel therapeutic targets for gastrointestinal motility disorders

The number of patients suffering from symptoms associated with gastrointestinal(GI) motility disorders is on the rise. GI motility disorders are accompanied by alteration of gastrointestinal smooth muscle functions. Currently available drugs,which can directly affect gastrointestinal smooth muscle and restore altered smooth muscle contractility to normal,are not satisfactory for treating patients with GI motility disorders. We have recently shown that ERK1/2 and p38MAPK signaling pathways play an important role in the contractile response not only of normal intestinal smooth muscle but also of inflamed intestinal smooth muscle. Here we discuss the possibility that ERK1/2 and p38MAPK signaling pathways represent ideal targets for generation of novel therapeutics for patients with GI motility disorders.     

血管内皮源性舒张因子对血管平滑肌钙激活钾通道活性影响的对比研究

目的　探讨血管内皮源性舒张因子对高血压及非高血压患者血管平滑肌钙激活钾通道 (KCa)活性的影响。方法　选择 2 0 0 1～ 2 0 0 3年泸州医学院附属医院 2 1例高血压病患者及 18例非高血压者 ,切取肠系膜动脉小分支节段用酶消化法获取血管平滑肌细胞 ,以膜片钳技术检测KCa通道的活性 ,通过Pclamp专用软件实时采样记录其平均开放时间 (To)、平均关闭时间 (Tc)、平均开放概率 (Po)等。采用硝酸还原法测定血浆一氧化氮(NO)含量 ,用比色法测定血浆一氧化氮合成酶 (NOS)含量。结果　 (1)两组对象KCa通道活性变化 :于细胞内面向外膜片下 ,高血压病组与非高血压组比较 ,前者KCa通道Po增加 ,Tc延长、To缩短。在浴液中分别加入Ca2 +后 ,两组KCa通道均被明显激活 ,与加Ca2 + 前比较 ,非高血压组Po的增加显著高于高血压病组 (P <0 0 1) ,说明高血压病组KCa通道对Ca2 + 的敏感性显著低于血压正常组。 (2 )高血压患者血浆NO、NOS较非高血压组显著降低。 (3)非高血压组血浆NO与KCa通道Po、To呈正相关 ,与Tc呈负相关。高血压病组NO与KCa通道Po、To、Tc的相关性明显弱于非高血压组。结论　高血压病患者肠系膜动脉平滑肌KCa通道活性明显增高 ,血管内皮源性舒张因子对非高血压及高血压病患者血管平滑肌KCa通道均有激活作     

玉米苞叶对动脉粥样硬化家兔平滑肌细胞凋亡及p53和Fas蛋白表达的影响

目的：探讨玉米苞叶防治动脉粥样硬化（AS）的机制。方法：选用大耳白家兔，复制家兔AS模型，随机分为动脉粥样硬化模型组，玉米苞叶组和正常对照组，成模后给予玉米苞叶煎剂治疗，8w后处死家兔，采用流氏细胞术检测平滑肌细胞的凋亡率以及凋亡相关基因p53和Fas蛋白表达。结果：模型组血管平滑肌细胞的凋亡率明显高于对照组（P＜0．05），p53和Fas蛋白的表达增强（P＜0．05），主动脉壁肉眼观测出现典型斑块。玉米苞叶组平滑肌细胞的凋亡率明显低于模型组（P＜0．05），p53和Fas蛋白表达下调（P＜0．05）；主动脉斑块面积较模型组明显减小，结论：玉米苞叶通过调节p53和Fas蛋白表达而调节AS家兔平滑肌细胞凋亡。     

Electromechanical effects of leukotriene D4 on ferret tracheal muscle and its muscarinic responsiveness

We investigated the possible electrophysiological processes by which leukotriene D₄ (LTD₄) affects airway smooth muscle and its responsiveness to acetylcholine (ACh). For study in vitro, preparations of ferret tracheal muscle (dissected free of overlying mucosal and submucosal layers) were used. These preparations were arranged so that force transducers and glass intracellular microelectrodes (having tip resistances of 35–60 megohm) could be used to measure isometric force generation and cell membrane potential (Em) simultaneously from muscle stimulated by LTD₄. At rest, the muscle was electrically and mechanically quiescent and had an Em of −59±0.2 mV (mean±SEM). We found that ferret tracheal muscle cells were relatively sensitive to LTD₄, and that both the resulting depolarization (beginning at 10⁻¹⁰ M LTD₄) and force generation (produced by higher concentrations) progressed in a concentration-dependent manner. Depolarization by 10⁻⁹ M LTD₄ elicited electrical oscillations. These oscillations were accompanied by phasic contractile activity at 5 × 10⁻⁹ M LTD₄. Verapamil abolished these oscillations and diminished force substantially. We also found that ACh depolarized and contracted the muscle in a concentration-dependent manner. It caused electrical oscillations at ≥ 10⁻⁶ M. Diltiazem abolished these oscillations and markedly diminished force generation without affecting Em. Preexposure of airway muscle preparations for 20 min to a concentration (10⁻¹⁰ M) of LTD₄ that, by itself, did not produce significant force, substantially augmented the voltage-tension relationship of the muscle upon ACh stimulation. We conclude that there is an electrical basis for the slow, prolonged force generation of airway muscle caused by LTD₄, and that LTD₄ potentiates the electromechanical responsiveness of the airway muscle to muscarinic stimulation.     

健脾祛痰化瘀方对氧化型低密度脂蛋白诱导血管细胞信号分子钙离子和蛋白激酶C表达的影响

为了探讨健脾祛痰化瘀方在抗氧化型低密度脂蛋白致动脉粥样硬化中对信号转导分子钙离子和蛋白激酶C的影响，分别以健脾祛痰化瘀方-沥水调脂胶囊含药血清(浓度分别为5％、10％和20％)、氧化型低密度脂蛋白(100mg／L)处理人脐静脉内皮细胞和人脐动脉平滑肌细胞，以流式细胞仪检测两种细胞胞质游离钙离子浓度，以液体闪烁仪检测平滑肌细胞胞膜蛋白激酶C活性。结果发现，沥水调脂胶囊含药血清对氧化型低密度脂蛋白引起的内皮细胞、平滑肌细胞胞质游离钙离子浓度升高及平滑肌细胞胞膜蛋白激酶C活性升高有明显的抑制作用，其中20％含药血清作用最为明显。结果提示，健脾祛痰化瘀方可能通过调节钙离子、蛋白激酶C两种信号传递分子的变化起抗氧化作用，进而抑制内皮细胞凋亡及平滑肌细胞增殖，达到阻止动脉粥样硬化发生的作用。     

阿托伐他汀对高血压大鼠动脉血压和血管平滑肌细胞离子泵活性的影响

目的探讨阿托伐他汀对自发性高血压大鼠的动脉血压及血管平滑肌细胞离子泵活性的影响。方法选用12周龄自发性高血压大鼠12只,随机分为阿托伐他汀治疗组(简称阿托伐他汀组,n=6)和蒸馏水组(n=6),并以正常血压大鼠作为对照组。阿托伐他汀组大鼠给以阿托伐他汀[50mg(kg·d)]加适量蒸馏水灌胃12周。观察给药前后大鼠尾动脉血压的变化,测定大鼠血清总胆固醇、甘油三酯和低密度脂蛋白胆固醇浓度,以及胸主动脉平滑肌细胞Na K ATP酶和Ca2 Mg2 ATP酶活性。结果阿托伐他汀组动脉血压显著低于蒸馏水组(161.8±9.9比192.9±10.4,P<0.05);阿托伐他汀组大鼠胸主动脉平滑肌细胞Na K ATP酶和Ca2 Mg2 ATP酶活性明显高于蒸馏水组(5.20±0.54比3.06±0.42,P<0.01;4.62±0.35比2.98±0.17,P<0.05),略低于对照组,而蒸馏水组则显著低于对照组(3.06±0.42比5.92±0.31,P<0.01;2.98±0.17比4.86±0.26,P<0.01)。Na K ATP酶活性、Ca2 Mg2 ATP酶活性与血压呈显著负相关(r=-0.426、r=-0.359,P<0.01)。结论长期应用阿托伐他汀可以显著降低自发性高血压大鼠血压。阿托伐他汀可能通过增高血管平滑肌细胞离子泵活性而影响血压形成的过程。     

Evaluation of acoustic properties of the live human smooth-muscle cell using scanning acoustic microscopy

This study was performed to measure the acoustic propagation speed in live human aortic smooth-muscle cells (HASMC), using scanning acoustic microscopy (SAM) and a novel measurement theory that permits the measurement of the acoustic propagation speed in biological samples of unknown thickness. C-mode and X–Z-mode images of HASMC under three different conditions: growing (G); differential (D); and on hypotonic loading (H), were acquired using 100-MHz, 450-MHz and 600-MHz ultrasound. The images exhibit features related to the cell surface curvature and intracellular structure. The theory supporting the methodology is derived in this article and makes use of the interference fringes within the focusing lens of the high-frequency transducer. The propagation speed in the cells was calculated from the location of the interference fringe on the C-mode images and the fringe shift on the X–Y-mode images with 450-MHz ultrasound. The propagation speed in D (1624 ± 16 m/s) was significantly higher than those in G (1571 ± 14 m/s, p < 0.05) and H (1585 ± 8 m/s, p < 0.05). Scanning acoustic microscope measurements, along with the described theory, are useful for studying the acoustic properties of live cells ex vivo and have applications in both pathophysiology and biomechanics.     

丹参对家兔实验性动脉粥样硬化预防作用的研究

丹参预防组主动脉斑块面积占主动脉总面积的百分比为（１９．８５±１１．７９％），明显小于动脉粥样硬化（ＡＳ）模型组（３７．７９±１０．８０％），Ｐ＜０．０５。丹参有显著保护超氧化物歧化酶（ＳＯＤ）活性和清除脂质过氧化物中间产物丙二醛（ＭＤＡ）的作用。丹参能明显抑制在高脂条件下３Ｈ－ＴｄＲ掺入培养的平滑肌（ＳＭＣ），抑制ＳＭＣ、ＤＮＡ合成。本研究初步探讨了丹参抑制家兔实验性ＡＳ病变发生发展的作用机制。     

Revised morphology and hemodynamics of the anorectal vascular plexus: impact on the course of hemorrhoidal disease

Purpose  The pathogenesis of hemorrhoidal disease is based mainly on the vascular hyperplasia theory. The aim of this study was to reassess the morphology and the functional mechanisms of the anorectal vascular plexus with regard to hemorrhoidal disease. Materials and methods  The anorectal vascular plexus was investigated in 17 anorectal and five hemorrhoidectomy specimens by means of conventional histology and immunohistochemistry. Vascular corrosion casts from two fresh rectal specimens were used for scanning electron microscopy. Transperineal color Doppler ultrasound (CDUS) with spectral wave analysis (SWA) was performed in 38 patients with hemorrhoidal disease and 20 healthy volunteers. Results  The anorectal vascular plexus was characterized by a network of submucosal vessels exhibiting multiple thickened venous vessels separated by distinct sphincter-like constrictions. CDUS and SWA showed significant flow differences in peak velocities (6.8 ± 1.3 cm/s vs. 10.7 ± 1.5 cm/s; P = 0.026) and acceleration velocities (51 ± 4 ms vs. 94 ± 11 ms; P = 0.001) of afferent vessels between the control group and patients with hemorrhoidal disease. Conclusions  Coordinated filling and drainage of the anorectal vascular plexus is regulated by intrinsic vascular sphincter mechanisms. Both morphological and functional failure of this vascular system may contribute to the development of hemorrhoidal disease.