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81.
Lymphoid cells in afferent and efferent intestinal lymph: lymphocyte subpopulations and cell migration. 下载免费PDF全文
Gut wall emigrating cells have been characterized in the intestinal lymph. The intestinal lymph duct was cannulated in 6-month-old minipigs. Under non-restraining conditions the efferent lymph from the mesenteric lymph nodes was collected in seven normal animals. Lymph coming directly from the gut (afferent lymph) was also collected in 18 pigs after resection of the mesenteric lymph node chains 3 months previously. The intestinal lymph flow was similar in both groups (around 18 ml/h). The lymphoid cell yield was 1.2 +/- 1.0 x 10(6)/h in control animals, while in mesenteric lymph node resected pigs it was around 20 times higher (26.2 +/- 17.6 x 10(6)/h). In the gut-derived lymph 76.5 +/- 8.8% T lymphocytes were observed (CD4+, 48.1 +/- 15.5%; CD8+, 53.6 +/- 12.7%). The percentage of immunoglobulin-positive cells was lower (IgM+, 10.1 +/- 4.5; IgA+, 1.7 +/- 1.1). In 14 mesenteric lymph node resected pigs a mean of 5.6 +/- 3.1 x 10(8) lymphocytes from the gut lymph were labelled in vitro with a fluorescent dye and retransfused. The labelling index of fluorescent cells in the intestinal lymph increased rapidly and remained at a high level until 44 h after cell transfusion. A four-to-ten times lower labelling index was found in the spleen, various lymph nodes and Peyer's patches. Most of the recovered lymphocytes were T cells. This model provides access to the cell pool leaving the gut wall, thus allowing an examination of its role in the gastrointestinal tract and other mucosal-lined organs. 相似文献
82.
The aim of the study was to test the hypothesis that baroreceptor unloading increases jejunal fluid absorption rate via an α2-adrenergic effect on electrogenic active transport. In 13 chloralose-anaesthetized cats, the carotid sinus baroreceptors were isolated and perfused with arterial blood, and we studied the effects of a graded decrease in carotid sinus pressure on intestinal vascular resistance, net fluid absorption rate and the potential difference between the intestinal lumen and the peritoneal cavity (PD). Experiments were performed in seven control animals and in six animals pretreated with yohimbine, an α2-adrenergic antagonist, at a dose of 0.1 mg kg-I i.v. Yohimbine per se had no significant effects on systemic arterial pressure, intestinal vascular resistance, net fluid absorption rate or PD. In the control animals, baroreceptor unloading induced an increase in systemic arterial pressure, intestinal vascular resistance and net fluid absorption rate, and a decrease in the PD. Yohimbine pretreatment did not significantly affect the systemic blood pressure response to baroreceptor unloading, but abolished the effect on intestinal vascular resistance and PD. After yohimbine treatment, decreases in carotid sinus pressure still enhanced net fluid absorption rate, but this response was observed in a higher range of carotid sinus pressures than in control animals. We conclude that (1) a major component of the increase in jejunal absorption rate during baroreceptor unloading is due to a non-electrogenic mechanism, which may be either active or passive; (2) this component of the response is not blocked by yohimbine at a dose sufficient for an effect on presynaptic α2-receptors; (3) the absorptive response to baroreceptor unloading is not a phenomenon secondary to the concomitant jejunal vasoconstriction. 相似文献
83.
T. GROTMOL J. T. RDNES T. BUANES G. CHRISTENSEN T. LANDSVERK 《Acta physiologica (Oxford, England)》1993,147(4):417-429
The aim of this study was to test whether atrial natriuretic factor (ANF) exerts any effect on human intestinal ion transport, and the porcine intestine was used as a positive control of ANF's effects. Tissues from human proximal (n = 6) and distal (n = 6) colons, and from distal ileum (n = 6) were mounted in Ussing chambers, and short circuit current (Isc) was measured subsequent to serosal application of ANF (10--6 m), 8–Br-cyclic guanosine monophosphate (8–Br-cGMP) (10--4 m), and theophylline (10--2 m). ANF did not affect Isc whereas 8–Br-cGMP increased Isc by 28 (8–53), 16 (3–36), and 16 (5–41) μA cm-2 in the distal colon (DC), proximal colon (PC) and distal ileum (DI), respectively. Likewise, transepithelial potential difference (PD) became more negative by 5.0 (0.6–8.9), 2.5 (0.4–4.0) and 0.9 (0.3–2.3) mV in DC, PC, and DI, respectively, subsequent to addition of 8–Br-cGMP. Isc and PD were further increased by theophylline. Additional radio-isotope flux studies in human colon revealed that ANF did not affect electroneutral sodium and chloride transport either. For comparison, ANF (10--6 m) was administered to large intestinal tissues from young pigs in which ANF induced a significant increase in Isc which was comparable to the 8–Br-cGMP response in humans. The porcine Isc response was partly inhibited by chloride-free solution on the serosal side, by serosal application of bumetanide (10--4 m) and BaCl2 (10--3 m), and mucosal application of the chloride-channel blocker diphenylamine-2–carboxylate (DPC) (10--3 m). Mucosal amiloride (10--5 m) pre-treatment reduced baseline Isc but did not affect the porcine intestinal Isc response to ANF. In vitro radio-autography demonstrated specific binding sites for ANF in porcine distal colon, whereas no apparent labelling was observed in human distal colon. These findings suggest that the lack of effect of ANF on sodium and chloride transport in human distal ileum and colon is probably due to lack of ANF receptors. In the porcine intestine, however, the IS0 response induced by ANF seems to involve stimulation of electrogenic chloride secretion, whereas electrogenic sodium absorption seems unaffected. 相似文献
84.
Interaction of cholecystokinin (CCK) with vasoactive intestinal peptide (VIP) in body shaking response to ice-water immersion was observed in pentobarbital-anesthetized rats. Although CCK itself had no influence on the response, VIP suppressed it and this effect of VIP was antagonized by simultaneous administration of sulfated octapeptide of CCK, but not by non-sulfated CCK. 相似文献
85.
用31具成人正常肝标本人工镂空,赛璐璐灌注正常新鲜尸肝6具,观察和测量了1~3级肝管长度、周径和夹角以及与肝动脉、门静脉相互关系;正常尸肝15具和30例肝内胆管结石并狭窄的肝标本,光镜观察各级肝管壁组织结构和病理改变。讨论了胆管结石存在部位,高位肝管剖开取石和行胆肠吻合术的术式选择及注意事项。 相似文献
86.
W H Berrettini J I Nurnberger P Hotvedt S Simmons-Alling E S Gershon 《Journal of affective disorders》1985,8(1):55-59
In an attempt to evaluate the role of VIP in affective disorder, measurements of lymphocyte VIP receptors, and plasma and CSF VIP levels were made in unmedicated and lithium-treated euthymic bipolars and controls. Lithium decreased plasma (P = 0.01) and CSF (P = 0.05) VIP levels and increased the affinity (decreased the KD) of the VIP lymphocyte receptor (P less than 0.01). This effect may be relevant to the psychotropic action of lithium in manic-depressive illness. 相似文献
87.
A. P. Avtsyn V. A. Shakhlamov R. S. Trager N. A. Kalinina I. R. Balyn' T. B. Timashkevich G. P. Polyakova 《Bulletin of experimental biology and medicine》1976,82(1):1045-1048
In a series of experiments 2250 tadpoles were infected with three strains of NAG vibrios. It can be concluded from the results of bacteriological and pathomorphological electron-microscopic and light-optical investigations that during the first 2 days the animals develop and recover from an acute infection, but the vibrios later persist for a long time in the body of the tadpoles and are excreted with the feces into the surrounding medium.Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 82, No. 7, pp. 841–843, July, 1976. 相似文献
88.
以基因表达谱芯片对Ty2 1a免疫前后小鼠肠细胞 (包括肠粘膜上皮细胞和肠上皮间淋巴细胞 )基因表达的差异性进行研究比较。将 490条经抑制消减杂交法筛选出的与小鼠Ty2 1a免疫相关的cDNA制备成表达谱芯片 ;利用免疫前后小鼠肠细胞的mRNA通过逆转录方法 ,将Cy3和Cy5两种荧光分别标记到两种组织的cDNA上 ,制备成cDNA探针 ,并与表达谱芯片进行杂交及扫描 ,单点重复 2次实验 ,通过计算机数据处理判定基因是否在上述两种细胞群中有表达差异。筛选出差异表达基因共 98条 ,其中 92条为表达上调基因 ,6条为表达降低基因。提示 ,基因表达谱芯片技术是高通量进行基因表达模式研究的方法 ,可同时定量研究大量的基因表达水平 ,从而鉴定可能参与免疫的基因。 相似文献
89.
P DESREUMAUX A LEVY J P VAERMAN M CAPRON A CORTOT J F COLOMBEL 《Clinical and experimental immunology》1996,104(2):293-296
The effects of nutrients on the mucosal immune system are poorly understood. The aim of this work was to study the cellular mucosal immune response to intrajejunal perfusion of an elemental diet (ED) or a control (C) electrolyte solution by measuring jejunal secretion of soluble CD4 (sCD4) and sCD8. sCD4 and sCD8 are markers of helper/inducer and suppressor/cytotoxic regulatory functions of T cells, respectively. A four lumen tube with a proximal occluding balloon at the angle of Treitz was used for jejunal perfusion in seven healthy volunteers (mean age 23 years). The length of the test segment was 40 cm. The jejunum was successively perfused with C for 80 min and then with ED containing 21.3g/l of free amino acids and 104.2g/l of oligosaccharides for 100 min. Jejunal fluid and serum concentrations of sCD4 and sCD8 were measured and their jejunal outputs calculated. When compared with C perfusion, jejunal perfusion with the ED resulted in a significant increase of sCD8 but not sCD4 jejunal secretion rates. sCD8 jejunal values increased early after ED perfusion and stayed at roughly the same level during the perfusion. Serum concentrations of sCD4 and sCD8 were not modified during ED perfusion. These data support the hypothesis that ED suppresses the immunologic tone of the gut, which could explain its beneficial effect in the management of intestinal inflammatory disease. 相似文献
90.
目的:探讨螺旋CT平扫和增强扫描对胃肠道间质瘤(GISTs)的诊断价值。方法:回顾性分析33例经手术、病理及免疫组化证实的GISTs患者螺旋CT表现。结果:平扫33例中,瘤体呈均匀等密度10例,肿块周边呈等密度中间略低或不均匀低密度23例。增强扫描16例中,病灶区呈中度或明显均匀强化9例,不均匀强化并可见囊状改变4例,病灶中央大片状坏死伴周边部明显强化3例。33例中良性9例,肿块直径多小于5cm,且呈圆形、类圆形,规则,边界尚清楚;恶性24例,直径多大于5cm,多数向腔外生长,边界不清楚,5例肿块中有坏死出血,4例发现转移灶。结论:螺旋CT检查对GISTs诊断虽无特异性,但可以准确定位,发现转移灶,显著提高GISTs的检出率,弥补常规胃肠道造影和内窥镜检查的不足,对GISTs术前定位和鉴别诊断均有重要价值。 相似文献