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Objective To establish the spatial course of distal tubule and afferent arterioles after macula densa, and to locate and detect the proteins in the adjacent parts by using three-dimensional visualization technology of microstructure. Methods C57 BL/6J mice were fixed by perfusion and embedded in epon 812. Tissue blocks were cut perpendicular to the longitudinal axis of the kidney. And a total of 720, 2. 5 μm-thick consecutive sections were obtained from the renal capsule to the outer stripe of the renal outer medulla. After aligning the digital microscopic images through computer registration procedures, the tubules and vessels were traced by 3D reconstruction program edited by C Language. Selecting the tissue sections of the contact site and applying the improved immunoperoxidase staining method to detect H
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Aim To analyze the blocking effect of ( ± ) doxazosin [ ( ± ) DOX ] , ( -) doxazosin [ ( -) DOX] and ( +) doxazosin [( +) DOX] on the vaso-constriction of rat isolated mesenteric arterioles media-ted by α1-adrenoceptors. Methods The vasoconstric-tion induced by phenylephrine ( Phe) in the rat isola-ted mesenteric arterioles ( the second- and third-order branches) was recorded using DMT wire myograph sys-tem 620M, and theα1-adrenoceptor antagonistic activ-ity of ( ± ) DOX and its enantiomers was analyzed. Results The inner diameter of second- and third-or-der branches of the rat mesenteric artery was (162. 5 ± 5. 3) μm (n=11) and (103. 1 ± 2. 3) μm (n=23), respectively. The values of normalized preload of the second-and third-order branches, which were calculat-ed by the LabChart software, were (2. 93 ± 0. 51) mN ( n =11 ) and ( 2. 64 ± 0. 50 ) mN ( n =23 ) ( P >0. 05 ) . Vasoconstrictive responses to Phe in the sec-ond-order branche of rat mesenteric artery under nor-malized preloads were not significantly different from those under 5 mN preload;however, the Emax values of the Phe-induced vasoconstriction under 10 mN, 15 mN and 20 mN preloads were decreased by 12%, 29%and 43% ( P<0. 01 ) respectively compared with those under normalized preload. The concentration-response curves for Phe were shifted to right in a concentration dependent manner by ( -) DOX or ( +) DOX at 0. 001 , 0. 01 and 0. 1 μmol · L-1 without significant change in their Emax values in the second-and third-or-der branches of rat mesenteric artery. Schild plot anal-ysis indicated that ( -) DOX, ( +) DOX and ( ± ) DOX non-competitively inhibited the vasoconstrictive responses to Phe in the second-order branches, and the rank order of pKB values was ( +) DOX ( 8. 67 ± 0. 10 ) , ( ± ) DOX ( 8. 53 ± 0. 090 ) , ( -) DOX (7. 85 ± 0. 09). However, schild plot analysis indica-ted that ( -) DOX and ( +) DOX competitively inhibi-ted the vasoconstrictive responses for Phe in the third-order branch, and the rank order of their pKB values was ( ± ) DOX ( 8. 68 ± 0. 17 ) , ( +) DOX ( 8. 48 ± 0. 10 ) , ( -) DOX ( 7. 48 ± 0. 140 ) . Conclusion The α1-adrenoceptor blocking activity of ( -) DOX is much weaker than that of ( +) DOX or ( ± ) DOX in the rat isolated mesenteric arterioles, and there is a tendency to enhance the activity of ( ± ) DOX in third-order branches of the rat mesenteric artery though theα1-adrenoceptor blockade effect of ( ± ) DOX is not significantly different from ( +) DOX.
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Objective To investigate the influence of flufenamic acid (FFA) on gap junction intercellular communication in vascu-lar smooth muscle cells(VSMC) in situ of acutely isolated arteriole segments .Methods Whole-cell patch clamp recordings were used to study the effects of FFA on membrane input capacitance (Cinput ) ,membrane input conductance(Ginput ) or membrane input re-sistance(Rinput ) of VSMCs embedded in arteriole segments .Results FFA concentration-dependently and reversibly suppressed Ginput or increased Rinput ,with an IC50 of 56 and 33μmol/L in acutely isolated mesenteric artery(MA) and brain artery(BA) segments re-spectively .There was not significant difference between MA and BA (P> 0 .05) .After application of FFA (≥ 300 μmol/L) ,the Cinput ,Ginput and Rinput of the in situ cells were very close to the respective dispersed cell in MA and BA .Conclusion FFA is a reversi-ble gap junction blocker ,achieving a complete electrical isolation of the recorded VSMC at ≥300 μmol/L .FFA suggesting a homo-geneous property of the gap junctions between MA and BA .
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We experienced an extremely unusual case of a 37-year-old woman who suffered from hemothorax soon after subclavian vein catheterization. Many case reports of a hemothorax or hematoma after central vein catheterization through the great vessels, such as the subclavian vein and internal jugular vein, have been published. However, this rare case showed a pinpoint-sized active bleeding site from a pulmonary arteriole rupture. During an emergency operation using thoracoscopy-assisted minithoracotomy, this bleeding site was successfully managed by primary repair.
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Adult , Female , Humans , Arterioles , Catheterization , Catheterization, Central Venous , Catheters , Emergencies , Hematoma , Hemorrhage , Hemothorax , Jugular Veins , Rupture , Subclavian Vein , VeinsABSTRACT
Aim To evaluate the endothelial dysfunction level of different arteries at different stages of SHR,and the recovery after administration.Methods SHR model was used,captopril(3.375 g·kg~(-1)·d~(-1)) was administered from week 7 to week 24 and the effects were observed continuously until 8 weeks post treatment.Pathological changes of aorta,mesenteric and apex cordis arteries were examined at the time points of 6,18,24,32 wk,and the endothelial-dependent relaxation of the former two preparations were tested by acetylcholine(ACh)(n=6).Results There were pathological changes in the thoracic aorta,mesenteric artery and arteriole at 18 wk,and aggravated along the age.The thoracic aorta demonstrated the most severe pathological changes appearing endothelial cells ablated and tunica media thickening.The significant decline of endothelium-dependent relaxation in aorta,and mesenteric arteries of SHR reflected an aging dependent change of vascular function with the most severe situation in the aorta(P=0.10,18 wk,P<0.01 24,32 wk);captopril increased the aorta vasodilatation of SHR at 18 wk time point,without the effect in mesenteric artery(P<0.05 vs SHR).Conclusions During the progress of SHR,endothelial damages have been observed in all three kinds of vasculatures together with the reduced endothelial-dependent relaxation.The aorta presents earlier and deeper damage than middle and small size vessels,and is sensitive towards the antihypertensive therapy such as the angiotensin converting enzyme inhibitor.
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Background: Information of the three dimensional (3D) structure of vascular smooth muscle cells (VSMCs) is essential for understanding the regulatory mechanism of blood flow in the microvascular system. objective: To examine the 3D structure of individual VSMCs in rabbit mesenteric arterioles, using confocal laser scanning microscopy. Methods: Japanese white rabbits were anesthetized with urethane and α-chlorase. After intravital observation of the mesenteric microcirculation under a videomicroscope, the intestine with mesentery was extracted and perfused and fixed with paraformaldehyde under a static pressure (100 mmHg). A section of the mesentery was isolated from the intestine and spread out to simulate the in vivo geometry of the the vascular network. The mesenteric section was stained with fluorescein anti-smooth muscle myosin antibody and rhodamine-labeled anti-rabbit Ig antibody. The samples were observed using confocal laser microscopy, and the 3D images were reconstructed by means of sliced images. The cross-sectional image was re-sliced to measure two axes of the best-fitting ellipse. Single VSMCs were picked out from the vascular wall using the continuity law of density distribution of vessel wall. Results: The cross-sectional shapes of arterioles were not circular but elliptical. The aspect ratio (major to minor axis) of the best-fitting ellipse was in the range from 0.3 to 0.7 for 28 arterioles (diameters: 10-30 μm). On the 3D image of VSMCs, the cell width ranged from 2.2 to 4.5 μm. The cells were classified into round and spindle types. The cell width of round shape was significantly larger than that of spindle shape. The VSMCs appeared to arrange circumferentially and tightly along the cross-section along the axis of vessel. The mean length of single VSMCs was approximately 1.2 times of the circumferential length of the arteriole. This cellular arrangement may have influence on the distribution of mechanical stress by VSMC-induced myogenic force. Conclusion: Confocal laser microscopy is useful for quantitative analysis of the 3D arrangement of individual VSHCs.
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Objective To study the roles of extracellular signal-regulated kinase(ERK1/2) and its substrate ets-like gene 1(Elk-1) in essential hypertension.Methods A comparative investigation was carried out to observe the expression of extracellular signal-regulated kinase1/2(ERKl/2) and Elk-1 in vascular smooth muscle cell (VSMC)and endothelium of gastrointestinal arterioles by means of immunohistochemistry in hypertension and nonhypertension patients.Results In the hypertension patients group,the positive rate of phosphorylated-ERK 1/2 in vascular smooth muscle cell(VSMC) and endothelium in gastrointestinal small arteries(8.32%and 4.97%,respectively) was significantly higher than that in the non-hypertension patients group(P
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Objective To compare the pathological changes of the kidney in two-kidney one-clip hypertension and spontaneous hypertension rats so as to provide some experimental basis for clinical prevention and treatment of primary and secondary hypertension. Methods Conventional histopathology and elastic staining methods were used to observe the morphological changes of kidney tissues and renal arterioles from two-kidney one-clip (2K1C) and spontaneously hypertensive rats (SHR) of different weeks of age. Results The blood pressure of 2K1C rats after 4 weeks of operation reached (187?24)mmHg,which was significantly higher than that of controls (P
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The external arteries of human medulla oblongata were examined and the internal arterial morphological features, distribution and the relation with the external arteries were investegated by using cleared slides of brain stem. The external arteries are divided into four groups: anteromedial group, anterolateral group, lateral group and posterior group. Those groups penetrate into the medulla and become corresponding groups of internal arteries. The anteromedial group of internal arteries supplies nervous structures on the sides of median line including hypoglossal nucleus and part of corticospinal tract The anterolateral group supplies corticospinal tract and inferior olivary nucleus. The lateral group supplies reticular formation, spinothalamic tract and dorsal vagal nucleus. Finally, the posterior group, gradually disappering at the upper part of medulla mainly supplies cuneat nucleus and gracile nucleus.
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Two methyl methacrylate corrosion casts prepared from the intra-microvascular system of human brain-stem were used for the observation of morphological features of the system. Arterioles, venules and capillaries have their own morphological features respectively, so it is not difficult to distinguish one from others. Besides different forms of impressions formed by the endothelial cells nuclei on the surface of larger arterioles and venules, there are semicir cular impressions formed by the smooth muscle cells on the surface of larger venules and the majority of larger venules take a looplike shape on their way to pass forward. All these characteristics could be used to distinguish the larger venules. There are anastomoses between arterioles and between venules, with some A-V communicating branches between arterioles and venules.
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The microvasculature of the lung of three humans was studied with the replicascanning electron microscopic method. The pulmonary arteriole belongs to microvasculature at the level of the respiratory bronchiole and gives out some side branches to the alveoli. The diameter of the arteriole is about 30-50 ?m. The arteriole divided into terminal arterioles, which accompanied with primary alveolar ducts. The diameter of the terminal arteriole is about 10-20 ?m, 17.35?1.62 ?m in average (n=30). There are obvious imprints of smooth muscles and endothelial nuclei on the surface of the casts of arteriole and terminal arteriole. The diameter of the alveolar capillary is 5.87?0.90 ?m in average (n=500). The proportion of the capillary area arround the alveole is 66?1.4%. There are two patterns of capillary network, i. e. long mesh and round mesh in type. The diameter of the mesh is (9.24?2.02)?(5.65?1.40) and 5.75?0.84 ?m, respectively. The distance of the mesh center is 17.13?1.74 ?m (long) and 11.52?1.12 ?m (short) in long mesh, and 11.63?0.88 ?m in round mesh. The capillary network of the long mesh located at the entrance and the base of the alveoli; and the round mesh in the area between them. The metaarteriole supplying the alveoli enters the alveoli at their entrance and thev venule draining the alveoli at their base. The distance between them is about 330 ?m.According to the microvascular architecture, the pulmonary microvasculature may be divided into three ordered units: i. e. the alveolar, the alveolar duct, and the respiratory bronchiolar units.