胃缺血和再灌注时胃表面激光多谱勒血流图像的显示

目的：连续检测和显示胃脏缺血和再灌注图像，研究胃脏血液供应血管的分布及激光多谱勒血流成像新技术在内脏血循环检测中的价值。方法：对大鼠胃右动脉进行结扎和松解，用激光多谱勒血流灌注成像仪（LDPI）对该过程中的胃脏整体表面循环予以图像显示，分析结扎和松解时胃血流的改变。结果：（1）胃脏表面的血流灌注图像显像清晰，呈现出从胃小弯向胃大弯放射状血流分布的扇形特征；（2）胃右动脉结扎后，激光多谱勒血流图上胃表面血流灌注下降非常显著，一直持续到松解结扎；（3）松解结扎后，血流即刻骤升，前10min内血流灌注量可超过结扎前水平，随后逐渐平稳。结论：结扎胃右动脉可以形成胃脏缺血和再灌注模型，LDPI能将胃脏的血循环状态以图像的形式大范围显示。     

激光多普勒流量计观察单侧输尿管梗阻大鼠双侧肾皮质微循环血流变化

目的:用激光多普勒流量计观察单侧输尿管梗阻大鼠双侧肾皮质微循环血流的变化,探讨梗阻侧肾间质纤维化的发病机制及健侧肾的代偿机制。方法:成年雌性SD大鼠,随机分为假手术组和模型组。假手术组仅将输尿管游离但不结扎离断,模型组行单侧输尿管结扎术。术后第7、14和21天随机选取并处死各组中的6只大鼠,观察双肾病理学改变,并检测双侧肾皮质微循环血流。结果:H-E染色显示假手术组双侧肾各时间点肾单位结构正常,间质无增宽;模型组大鼠梗阻侧肾术后7 d出现早期间质纤维化的病理改变,并随梗阻时间延长逐渐加重;健侧肾小球系膜细胞增生并随代偿时间延长逐渐增多。肾皮质微循环血流,与假手术组比较,模型组大鼠健侧肾皮质微循环血流显著增加,梗阻侧肾皮质微循环灌注量先增加后进行性降低。结论:血液流变学改变、梗阻侧肾皮质微循环血流灌注量进行性减少是肾间质纤维化的发病机制之一;而健侧肾皮质微循环血流灌注量增高,在一定程度上有利于健侧肾的功能代偿。     

急性DIC时皮肤及内脏微循环血流量的变化

健康大耳白兔26只。用激光多普勒血流计测定皮肤与肾脏、肝脏、胃、空肠及结肠表面微循环血流量,随机分为三组:急性DIC组(n=10)、山莨菪碱治疗组(n=10)和对照组(n=6)。以凝血酶(60u/kg)加氨基乙酸(0.4克/kg)静脉输注1小时复制急性DIC模型,实验30、60、120分钟测定上述脏器表面微循环血流量变化。结果急性DIC组皮肤与肾、肝、胃、空肠及结肠微循环血流量在120分钟均较对照组明显降低,三组动物皮肤微循环血流量的变化与上述内脏表面微循环血流量的变化呈高度正相关。结果提示急性DIC时及山莨菪碱治疗后皮肤微循环血流量的动态变化可间接反映肾、肝、胃肠道微循环血流量的变化。     

蝮蛇抗栓酶对失血性休克动物肾微循环血液灌流量的影响

在40只失血性休克大鼠中静脉注射不同剂量的蝮蛇抗栓酶(0.05U,0.025U/100g B.W.)后用激光多普勒微循环血流量计测定肝、脾、肾、小肠及尾部微循环血流量,结果发现肾微循环血流量在用药后5～20分均有显著增加(P<0.05),在15只家兔的类似实验中同时测定肾表面微循环血流量与肾动脉血流量(电磁血流量计),结果发现静脉注射蝮蛇抗栓酶后(0.05U/ml/kg),肾动脉血流量并无明显增加,而肾皮质微循环血液灌流量显著增加,并与尿量增加一致。作者认为蝮蛇抗栓酶具有降低肾微循环血流阻力,加快流速,增加肾皮质微循环血液灌流量的作用。     

实验高压电烧伤肠系膜微循环动态变化及意义

目的探索高压电对机体内脏微血管及微血流动力学的影响,为电烧伤后脏器损伤的防治提供理论依据。方法复制家兔高压电烧伤模型,用WX-9B型微循环显微镜及视频图像分析系统,观测肠系膜微血管形态、微血流流态及微血管周围状态的变化。结果与对照组比较,电烧伤组肠系膜微血管形态、微血流流态及微血管周围状态均发生变化,高压电对微动脉与微静脉管径均有影响,且两者存在交互作用(P<0.001);微血管周围渗出与出血的生存曲线分析,对照组与电烧伤组比较有显著性差异(P<0.001)。结论高压电能引起家兔肠系膜微循环发生病理性改变。     

原发性高血压大鼠血浆外泌体水平及其与微循环变化的相关性研究

目的:研究13周龄原发性高血压大鼠(SHR)外周血外泌体数量和大小分布与微循环功能的相关性。方法:市购13周龄雄性SHR(实验组)和相同周龄的WKY大鼠(对照组)各7只。采用多功能激光多普勒血流探测仪(LDF)检测两组大鼠耳廓、趾及脑皮质血流量、血细胞聚集度和血流速度,采用血流成像技术(LDPI)观察脑皮质血流分布。取外周血,提取血浆外泌体,采用透射电镜观察外泌体形态,以Apogee流式细胞术检测总外泌体水平和直径100nm的外泌体水平,分析实验组大鼠外泌体水平与其微循环指标的相关性。结果:LDF结果显示,实验组大鼠脑皮质血流量和血流速度均显著高于对照组(P0.05或P0.01),而实验组大鼠趾血流量和血流速度明显低于对照组(P0.05),两组大鼠的耳廓血流量、血流速度及耳廓、趾和脑皮质的血细胞聚集度差异均无统计学意义(P0.05);LDPI结果显示,实验组大鼠脑皮质血流灌注量显著高于对照组(P0.01)。体外实验显示,实验大鼠血浆外泌体大小分布不均,但以直径100nm者居多;实验组总外泌体水平和直径100nm外泌体水平均明显高于对照组(P0.05)。相关性分析显示,实验组大鼠血浆总外泌体和直径100nm外泌体水平与脑皮质血流量呈显著正相关(P0.01)。结论:脑微循环功能改变与血浆总外泌体含量,尤其直径100nm的外泌体水平显著相关,提示外泌体水平的升高可能预警原发性高血压发生和发展过程中的微循环变化,或可作为高血压早期的监测标记物。     

一级感觉神经元周围突分支支配多个内脏器官的研究——荧光素逆行双标及三标法

将大鼠颈、胸、腹、盆腔多个脏器配对:食管-甲状腺、食管-气管、心-胃、肺-胃、左肾-脾、膀胱-直肠、膀胱-子宫、子宫-直肠。在配对脏器中先后注入碘化丙啶(PI)或快蓝(FB)及双苯甲亚胺(Bb)或核黄(NY),于迷走神经上、下节及相应背根神经节内出现PI与Bb(或FB与NY)的双标细胞。另设膀胱-子宫-直肠组,分别注入PI、FB及NY,在L_(1～2)背根节出现极少量PI、FB与NY三标细胞。结果提示,大鼠体内普遍存在内脏-内脏感觉在同一感觉细胞的汇聚。     

实验性家兔动脉粥样硬化血管外器官的病理学变化

对50办家兔实验性动脉粥样硬化的血管及血管以外心、肝、脾、肺、肾等脏器,进行了系统的病理形态学观察,试图探讨动脉粥样硬化形成过程中高脂血症对内脏器官的影响。结果表明,高脂血症不仅可以诱发家兔动脉粥样硬化,也可使受试动物产生肺炎,肝细胞广泛脂变和水变,以及全身单核巨噬细胞系统反应。并着重讨论了内脏器官病变的发病机理。     

电针不同穴位对肠易激综合征模型大鼠内脏敏感性及肠系膜微循环的影响

目的:观察电针天枢、足三里穴对肠易激综合征(IBS)模型大鼠内脏敏感性及肠微循环的影响。探讨针刺治疗IBS的部分机制。方法:将Wistar幼鼠分为正常组、模型组、天枢组、足三里组,每组6只。天枢组和足三里组从实验第6周开始电针介入,隔日1次,共7次。模型组只束缚不针刺,正常组不作任何处理。治疗结束第二天采用XW-B-3冷光源微循环显微仪观察各组大鼠肠系膜微循环不同时点管径和血流速度的变化。结果:(1)内脏敏感性评估:与正常组比较,模型组大鼠腹部抬起、背部拱起值明显降低(P<0.01),与模型组比较,电针天枢、足三里组大鼠腹部抬起、背部拱起值明显升高(P<0.01)。(2)肠系膜微循环检测:①血管直径:与正常组比较,模型组大鼠肠系膜微血管明显收缩(P<0.05);与模型组比较,电针天枢组、足三里组大鼠肠系膜微血管明显扩张(P<0.05或P<0.01);②血流状态:与正常组比较,模型组大鼠肠系膜微循环血流速度明显减慢或停止(P<0.01)。结论:针刺天枢、足三里可明显提高IBS大鼠内脏敏感性阈值,降低IBS大鼠内脏敏感性;明显改善肠系膜微循环血流状态和血管痉挛,从而缓解肠黏膜缺血、缺氧,缓解腹部疼痛。     

川芎嗪对失血性休克家兔肠系膜毛细血管血流动力学的影响

家兔１６只，随机分为生理盐水对照组和川芎嗪治疗组，麻醉后造成失血性休克，用显微电视录像静像步进技术测定川芎嗪对小肠系膜毛细血管内径、血流速度及血流量的作用。结果提示，川芎嗪比对照组可加快失血性休克家兔小肠系膜毛细血管血流速度、改善肠系膜微循环血流灌注，但对毛细血管口径无明显作用。     

尾加压素Ⅱ对大鼠肠系膜微循环的影响

目的: 探讨尾加压素(UII)对于大鼠肠系膜微循环的影响。方法: 采用活体微循环观测技术观察UII对于SD大鼠肠系膜微血管内径、血流速度的作用,采用激光多普勒血流量仪测定肠壁血流量的变化。结果: 正常对照组肠系膜细动脉和细静脉血管内径分别为(21.4±2.3) μm和(38.1±3.6) μm,UII组于滴加UII(10^-7mol/L)后即刻细动脉和细静脉出现收缩,1 min时细动脉和细静脉收缩达到高峰,血管内径分别为(14.1±1.4) μm和(22.2±5.2) μm(与正常对照组比较,P<0.05);细动、静脉内血流速度无明显变化(与正常对照组比较P>0.05);肠壁血流量于滴加UII(10^-7 mol/L)后1 min开始升高,5 min达到高峰 。结论: UII可以使大鼠肠系膜微血管收缩,血流量增加。     

Plasma Protein Dynamics: Albumin and IgG Capillary Permeability,Extravascular Movement and Regional Blood Flow in Unanesthetized Rabbits

The turnover rate constants for extravascular albumin and immunoglobulin-G (IgG) and the turnover rates and extravascular spaces for the proteins and regional blood flow were determined in different tissues in unanesthetized rabbits. The turnover rate constant in percent per minute for extravascular albumin was 1.9 in the kidney cortex and 1.4 in the kidney medulla, about 0.8-1.4 in the lung, small intestine, choroid plexus and heart muscle and about 0.2-0.6 in the skeletal muscle, stomach wall and gall bladder. The turnover rate constants for IgG were similar or lower. The plasma equivalent extravascular albumin space was 145 μl/g in the kidney medulla, about 100 μ1/g in the gall bladder, heart muscle, choroid plexus and small intestine, 30–70 μl/g in the kidney cortex, lung, stomach wall and triceps muscle. The extravascular IgG spaces were similar or smaller. In the liver, spleen and adrenals where extravascular spaces could not be determined, the ratios total IgG space/total albumin space were about 1.3-1.5. Extraction of albumin defined as turnover rate of extravascular albumin/regional plasma flow could not be determined in the liver, spleen and adrenals. It was zero in the brain cortex, about 0.001 % in the lung and around 0.01-0.05 % in most other tissues. The results suggest that in the walls of the capillaries of the kidney cortex, stomach wall, skeletal muscle and gall bladder there was convection of the proteins with pinocytosis and/or through large pores, diffusion playing little role. The albumin and the IgG passed through the tissues and were drained essentially by bulk flow. In the heart muscle, choroid plexus, lung and small intestine there seemed to be some diffusion of albumin through the capillary wall in addition to convection. Accumulation of IgG in the liver, spleen and adrenals was probably caused by adsorption to cells belonging to the RES.     

Renal autoregulation of blood flow and filtration rate in the rabbit

Electromagnetic flow techniques and inulin clearance were used to determine the autoregulatory capabilities of the rabbit kidney in vivo. Renal blood flow was measured in 13 animals over a renal perfusion pressure range of 40-110 mmHg. Normal renal blood flow averaged 3.2 +/- 0.3 ml.min-1.g kidney-1 and was efficiently autoregulated above a renal artery pressure of 75 mmHg. For every 10 mmHg renal pressure change above 75 mmHg renal blood flow changed only 0.96%. Renal perfusion pressure was reduced from 102 +/- 3 to 74 +/- 2 mmHg in six animals. Over this pressure range glomerular filtration rate was not significantly decreased and averaged 4.2 +/- 0.5 ml/min at high pressure compared to 4.0 +/- 0.5 ml/min at low perfusion pressure. Results show that the rabbit kidney autoregulates renal blood flow and glomerular filtration rate efficiently above 75 mmHg. This range of autoregulation compares well with the autoregulatory range of the dog. The results also show that in the autoregulatory range the rabbit and the rat appear to autoregulate with equal efficiency but that the rabbit kidney begins to autoregulate at a low perfusion pressure than the average of approximately 100 mmHg usually found in the rat.     

The origin of sensory innervation of the peritoneum in the rat

The distribution of sensory neurons innervating the peritoneum was studied using axonal transport of fluoro-gold. The tracer was injected into parietal peritoneum, diaphragm, mesentery, mesocolon, visceral peritoneum covering the stomach, small intestine, colon, liver, spleen, kidney, urinary bladder or uterus. After ten days of survival bilateral dorsal root ganglia from C2 to S6, and the nodose ganglia were dissected. The cryostat sections of these ganglia were mounted on glass slides and observed with a fluorescence microscope. In cases where the tracer was placed on the peritoneum covering the abdominal wall, labeled neurons were observed only in the ipsilateral dorsal root ganglia. A small number of neurons in nodose and cervical dorsal root ganglia of both sides were labeled after placing the tracer on the central part of the diaphragm. When fluoro-gold was applied to the peripheral part of the diaphragm, nodose ganglion was negative, and dorsal root ganglia from T6 to T12 were positive. Many neurons in the nodose ganglia in addition to somata in the dorsal root ganglia from T4 to T13 were labeled when the tracer was placed on the peritoneum lining the stomach, small intestine or caecum. After applying the tracer onto the colon, labeled neurons were observed in the dorsal root ganglia from T13 to L2 and L5 to S1. Ganglion cells in the nodose and dorsal root ganglia from T5 to T13 were positive when fluoro-gold was placed on the mesentery. No labeled neurons were observed in any ganglia when the tracer was applied to the peritoneum covering the spleen, kidney, uterus, urinary bladder and liver. These results suggest that most of the parietal peritoneum receives sensory nerves from dorsal root ganglia and the visceral peritoneum from both spinal nerves and the vagus nerve.     

Laser speckle imaging of blood flow in microcirculation

Monitoring the spatio-temporal characteristics of microcirculation is crucial for studying the functional activities of biotissue and the mechanism of disease. However, conventional methods used to measure blood flow suffer from limited spatial resolution or the injection of exogenous substances or the need of scanning to obtain the dynamic of regional blood flow. Laser speckle imaging (LSI) technique makes up these disadvantages by obtaining the regional blood flow distribution with high spatio-temporal resolution without the need to scan. In this paper, LSI was introduced to investigate the dynamic responses of the rat mesenteric microcirculation to an incremental dose of phentolamine. The results showed that when the dose of phentolamine was less than 4 microg ml(-1), local application of phentolamine on the mesentery would increase the blood perfusion as the concentration increased. When the dose increased further, the improvement decreased. At a dose of 200 microg ml(-1), a microcirculation impediment was caused. At the same time, different responses between veinules and arterioles were manifested. These suggested that LSI is promising to be a useful contribution to drug development and testing.     

Sympathetic skin vasoconstriction--further evaluation using laser Doppler techniques.

The aim of this study was to quantify the reflex sympathetic vasoconstriction in skin at different depths. Twenty healthy subjects were studied. Finger skin blood flow was measured using laser Doppler perfusion imaging (LDPI) and laser Doppler perfusion monitoring (LDPM). In LDPM, a probe with fibres separated 0.25 mm (deep) and 0.14 mm (superficial) from the illuminating fibre was used. Local heating (40 degrees C) was achieved with a Peltier element, and reflex vasoconstriction induced by immersion of the contra-lateral hand and forearm for 3 min in water at 15 degrees C. The change in skin blood flow was measured and a vasoconstriction index (VAC: cooling/before cooling) calculated. VAC indices of LDPI, LDPM-0.25 and LDPM-0.14 were 0.60, 0.59 and 0.60, respectively. The two components of the LDPM perfusion value, blood cell velocity and concentration, were studied separately. Their contributions in LDPM-0.25 were roughly the same, whereas the velocity component dominated in LDPM-0.14, although their relative responses in the two channels were similar. We conclude that sympathetic skin vasoconstriction does not significantly differ in two compartments, as probed with fibres separated by 0.25 and 0.14 mm. Blood cell velocity is influenced in a proportional way, as is concentration.