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61.
本实验在40只大鼠经伺服零测压技术测定的肾脏微血管内压力分布及其ANP的作用均随血管树各段的口径变化而改变。分析小球前各段血管的压力降所占动脉总压降的比例得知:小叶间动脉占总压降的88%。肾小球毛细血管和出球小动脉亦具有较大的压力降。正常对照情况下,肾小球前血管内的压力分布与内径呈直线相关(r=0.869,n=65,P<0.01),其回归方程为平均压()=34.71±0.798×血管内径(D)。给ANP后肾小球前血管内的压力与内径仍呈直线相关(r=0.931,P<0.01),回归方程式为()=38.53+0.765D,其曲线右上移。本文结果提示,肾小球前微血管内压力分布与血管内径密切相关。小叶间动脉的阻力较大。  相似文献   
62.
目的:观察缺血后处理(I-postC)对大鼠后肢骨骼肌微循环和缺血再灌注(I/R)损伤的影响。方法:健康雄性Wistar大鼠24只,随机分为3个实验组,即I/R组、I-postC组和预处理(IPC)组(n均=8),左后肢作为自身对照。无创动脉夹夹闭右侧股动脉4h,松夹再灌注2h建立大鼠后肢I/R模型。于再灌注结束时分别检测大鼠胫前肌血氧饱和度(StO2)、微循环、血流动力学变化以及骨骼肌湿、干重比值(W/D)和骨骼肌组织丙二醛(MDA)含量。结果:(1)再灌注I-postC减轻I/R对心功能的抑制,I-postC组+dp/dtmax和-dp/dtmax较I/R组分别增高18.5%和21.3%(P<0.05),I-postC组W/D较I/R组降低4.9%(P<0.05);I-postC组MDA较I/R组降低40.9%(P<0.05)。(2)再灌注I-postC组实验侧细静脉血流速度较I/R组增加8.3%(P<0.05),细动、静脉收缩减轻(细动、静脉内径较I/R组分别增加14.8%和29.1%,P<0.05),与IPC的保护效果接近(P>0.05)。结论:I-postC显著减轻骨骼肌I/R损伤,其保护机制与改善微循环有关。  相似文献   
63.
Photoplethysmography (PPG) records the cardiac-induced changes in tissue blood volume by light-transmission measurements. The baseline and amplitude of the PPG signal show very low-frequency (VLF) spontaneous fluctuations, which are mediated by the sympathetic nervous system, and high correlation between right and left extremities of healthy subjects. As sympathetic neuropathy is one of the diabetic complications, the right-left correlation of the PPG fluctuations was examined in diabetic patients. The PPG signal was simultaneously measured in the two index fingers and the two second toes of 35 diabetic patients and 33 non-diabetic subjects. For each PPG pulse, the baseline and amplitude were determined, and the right-left correlation coefficients of the VLF fluctuations in the baseline and amplitude were derived. The VLF fluctuations in the baseline showed high right-left correlation, both for fingers (0.93±0.05) and toes (0.93±0.06), for the non-diabetic subjects, and significantly lower correlation (0.78±0.22 and 0.84±0.17, respectively) for the diabetic patients. Similar results were obtained for the amplitude VLF fluctuations. The right-left correlation coefficients for diabetic patients decreased with the disease duration for the toe baseline and toe amplitude fluctuations and correlated with heart rate response to deep breathing for the finger baseline and toe amplitude fluctuations. The right-left correlation coefficients of the PPG fluctuations provide a simple and convenient means for assessing the adequacy of the sympathetic nervous system function.  相似文献   
64.
深低温体外循环对犬趾蹼微循环指标的研究   总被引:1,自引:2,他引:1  
本研究表明,深低温体外循环时,犬趾蹼微循环发生的变化与温度有关。平均动脉压(MAP)的变化不能反映组织灌注的优劣情况。毛细血管内的血流速度与灌注流量的高低有关。  相似文献   
65.
目的:在兔心肌缺血/再灌注前处置模型的基础上,了解NO在心肌缺血前处置中所起的作用及意义。方法:采用免麻醉后开胸结扎左冠状动脉降支,反复结扎(缺血)10分钟,放开(再灌)5分钟,最后结扎30分钟再灌20分钟造成缺血/再灌注前处置模型后,对比观察了各组动物血浆中NO、TXB2、6-K-PGF1α、SOD和MDA浓度的变化,以及各组动物球结膜微循环及心肌病理学的变化。结果:前处置组血浆NO、6-K-PGF1α、SOD浓度显著高于缺血/再灌注组,而MDA、TXB2浓度明显低于缺血/再灌注组。前处置组心肌超微结构损伤明显轻于缺血/再灌注组,球结膜微循环基本正常。结论:心肌缺血前处置可增加心血管内皮细胞合成NO,而NO具有减轻心肌缺血/再灌注损伤、改善微循环障碍的作用。  相似文献   
66.
For a reasonable analysis of sperm motility, consideration should be given to the morphology of the flagellum. Among various tail disturbances, the present paper describes a structural shaft defect that is characterized by variations in diameter, poor outline and/or lacking endpiece. Electron microscopical examinations, especially the negative staining technique, have shown that in addition to membrane alterations there is one essential cause for the limited extension of the outer dense fibres. This disturbance may be of genetic origin or due to toxic or inflammatory influences. Further molecular biological studies are required to detect the actual cause of this defect, for which there is so far no adequate therapy.  相似文献   
67.
对黄杨碱治疗的62例冠心病心绞痛甲襞微循环变化进行观察。结果表明:96.8%(60/62)的病例甲襞微循环有异常改变,且病情愈重其改变愈明显。用该药4.5mg/日(1.5mg,tid)治疗60天结果显示:绝大多数微循环异常指标都获改善(P<0.05~0.01),并认为该药有部分类似茛菪类药物的作用。对少数严重病例的异常微循环改善不明显。心绞痛缓解率及心电图(ST、T)改善率分别在70%以上及50%~70%之间。面药对降高明固醇及高甘油三酯作用不明显(P>0.05),而对升高高密度脂蛋白具有较好疗效(P<0.05)。该药无明显毒副作用。  相似文献   
68.
Objective: The aims of the present study were to elucidate the interaction of reactive oxygen species (ROS) and Ca2+ response in central nervous system (CNS) pericytes. Methods: The intracellular Ca2+ concentration was measured using fluorescent Ca2+ indicator, fura-2, in cultured CNS pericytes. Results: Hydrogen peroxide evoked a dose-dependent increase in cytosolic Ca2+, which was completely inhibited by catalase. Removal of external Ca2+ or addition of nicardipine (1 μM) during application of hydrogen peroxide did not affect Ca2+ response. Incubation of the cells in Ca2+ free solution did not abolish but slightly reduced Ca2+ response by hydrogen peroxide. Ca2+ response to hydrogen peroxide was not altered by the depletion of intracellular Ca2+ by thapsigargin (1 μM). Pretreatment of the cells with tyrosine kinase inhibitor genistein (100 μM) or tyrphostin A47 (30 μM) significantly reduced Ca2+ increase by hydrogen peroxide. Conclusions: These results indicate that hydrogen peroxide evokes Ca2+ increase predominantly by release from intracellular Ca2+ store, which may be regulated by tyrosine kinases.  相似文献   
69.
Summary 1. The distribution and microvascular effects of substance P (SP) and calcitonin gene-related peptide (CGRP) were studied in the rabbit tenuissimus muscle using immunohistochemistry and intravital microscopy. 2. Individual fibers within nerve bundles and along blood vessels in the muscle were found to be immunoreactive (IR) for both SP and CGRP, thus showing an apparently complete coexistence for these peptides. In dorsal root ganglia most SP-positive cells were also CGRP-IR, but the latter cells were somewhat more numerous than SP-IR cells. 3. When applied topically to the muscle, both SP and CGRP increased blood flow in a dose-dependent manner, but CGRP was more potent and caused responses of longer duration. Both SP and CGRP dilated transverse arterioles, but they had little or no effect on the smaller terminal arterioles. This resulted in a redistribution of blood flow to the connective tissue adjacent to the muscle. 4. SP, but not CGRP, elicited vigorous vasomotion in larger arterioles and caused the formation of aggregates of platelets and leukocytes in the venules. Neither flow increase, nor vasomotion or aggregate formation were influenced by pretreatment of the animals with mepyramine, cimetidine or indomethacin. Capsaicin (1 M) had a powerful effect on transverse arterioles resembling that of both SP and CGRP. 5. It is concluded that some of the vascular effects hitherto ascribed to SP on the basis of nerve stimulation and application of capsaicin might, at least in part, be due to release of CGRP. Send offprint requests to: A. Ohlen, Department of Physiology, Karolinska Institutet, S-104 01 Stockholm, Sweden  相似文献   
70.
目的:基于药症相应,探讨历代本草治窍思路,以指导临床辨治用药。方法:检索《中华医典》数据库中本草类的全部文献数据,涉及本草著作76部,涵盖汉至明清各时期具有代表性的存世的本草著作,收集整理其治窍的本草信息,依照《中药学》(第十一版)及2020年版《中华人民共和国药典》,对筛选纳入的本草进行性味归经统计分析,以治窍病机要素进行分类统计,提取各类本草的辨治论述内容。结果:在76部历代本草专著中,筛选出93味治窍本草。在治窍本草性味归经上,药性以温性为主,其次为寒性、平性等;药味以辛味为主,其次为苦味、甘味等;归经以肺经为主,其次为胃经、心经、肝经、脾经、肾经等。在以治窍病机要素本草分类中,可划分为风邪袭扰、浊阻气滞、水湿停滞、血瘀络阻、火热毒损、正虚寒凝六类病机要素。结论:治窍辨治用药以祛风散邪药、化浊行滞药、利水渗湿药、活血通络药、清热泻火药、补虚散寒药为主,且互相联合运用;祛邪通利、补虚泻实为治窍辨治主要特点,符合窍失空灵、邪阻正虚的生理功能紊乱状态。  相似文献   
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