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1.
E-cadherin is a cell adhesion molecule that plays an important role in maintaining renal epithelial polarity and integrity. The purpose of this study was to determine the exact cellular localization of E-cadherin in pig kidney. Kidney tissues from pigs were processed for light and electron microscopy immunocytochemistry, and immunoblot analysis. E-cadhedrin bands of the same size were detected by immunoblot of samples from rat and pig kidneys. In pig kidney, strong E-cadherin expression was observed in the basolateral plasma membrane of the tubular epithelial cells. E-cadherin immunolabeling was not detected in glomeruli or blood vessels of pig kidney. Double-labeling results demonstrated that E-cadherin was expressed in the calbindin D28k-positive distal convoluted tubule and H+-ATPase-positive collecting duct, but not in the aquaporin 1-positive, N-cadherin-positive proximal tubule. In contrast to rat, E-cadherin immunoreactivity was not expressed at detectable levels in the Tamm-Horsfall protein-positive thick ascending limb of pig kidney. Immunoelectron microscopy confirmed that E-cadherin was localized in both the lateral membranes and basal infoldings of the collecting duct. These results suggest that E-cadherin may be a critical adhesion molecule in the distal convoluted tubule and collecting duct cells of pig kidney.  相似文献   

2.
This study was conducted as a comparative analysis of the immunohistochemical localization of calbindin D-28k, parvalbumin and the calcitonin gene-related peptide (CGRP) in the cervical through the sacral spinal cord of mongrel dogs, to reveal any distinct patterns of distribution and possible involvement in spinal processing. In laminae I and II of the substantia gelatinosa, both calbindin D-28k and CGRP showed strong immunoreactivity, with calbindin D-28k being positive in both cells and fibres, while CGRP was positive in fibres only. Parvalbumin and CGRP immunoreactive cells were widely distributed in various nuclei and lower motor neurones in the ventromedial horn. In addition, the lower motor neurones expressed CGRP as well as parvalbumin, but not calbindin D-28k. These results are generally consistent with previous reports, and the co-localization of parvalbumin and CGRP may explain the functional improvement of lower motor neuron disease.  相似文献   

3.
目的:采用灌胃法诱导SD清洁级小鼠脾虚动物模型,造模完成后检测小鼠肾脏中Bcl-2、Fas和Bax蛋白表达的改变,并探讨其意义。方法:采用大承气汤诱导小鼠脾虚模型,H.E染色后光镜下观察肾脏局部形态,SP法检测Bcl-2、Fas和Bax蛋白在肾脏细胞中的表达。结果:脾虚组小鼠肾小球部位出现炎症,肾近曲小管和远曲小管部位出现凝固性坏死;肾脏细胞中Bax和Fas蛋白的表达率升高(P<0.05),Bcl-2表达降低(P<0.05)。结论:脾虚会引发肾脏发生病理变化,同时会使Bax和Fas蛋白的表达升高,Bcl-2蛋白的表达下降,增加了肾脏细胞发生凋亡的机率。  相似文献   

4.
双峰驼肾近曲小管和远曲小管的体视学研究   总被引:1,自引:0,他引:1  
应用光镜和电镜技术,测算了双峰驼肾近曲小管和远曲小管微细结构的体视学参数,并与黄牛进行了比较.结果显示,双峰驼肾近曲小管刷状缘体积、微绒毛表面积、吞饮小泡和溶酶体体积均显著大于黄牛;远曲小管上皮细胞的线粒体体密度、侧基底面质膜面密度和周界长度也明显大于黄牛.这些结构的差异表明,双峰驼肾脏重吸收水分的能力更强大.  相似文献   

5.
It is well established that the kidney plays an essential role in regulating the homeostasis of body fluids. Recent studies provided evidence for the kidney to be an important organ for the regulation in the metabolism of both fat (vitamin A, D) and water soluble vitamins (e.g. vitamin B12). This regulation is mediated by glomerular filtration as well as reabsorption and secretion processes of protein-bound vitamins. Vitamin transport proteins such as retinol-binding protein, vitamin D-binding protein and transcobalamin II are filtered in renal glomeruli and subsequently reabsorbed in the proximal tubules by endocytosis from the tubular fluid. Megalin, a scavenger receptor belonging to the LDL receptor family, is probably the most important receptor in this process in the proximal tubule cells. The carrier proteins are degraded in lysosomes whereas the vitamins are probably stored, may become coupled to newly synthesized carriers and secreted at the basolateral plasma membrane. A renal vitamin excretion is observed in dogs and other species of the family Canidae, in form of fat soluble retinol and retinyl esters bound to Tamm-Horsfall protein. This and the high vitamin A concentrations in renal tissue of canines suggest an important role of the kidneys in vitamin A metabolism of these species.  相似文献   

6.
Megalin, retinol-binding protein (RBP) and Tamm–Horsfall glycoprotein (THP) are involved in the renal metabolism of vitamin A in canine species. The presence of megalin, RBP and THP in the kidneys of dogs was investigated using immunohistochemical methods. Megalin was highly expressed in the apical membrane of the proximal convoluted and straight tubule cells. Immunoreactive RBP was detected below the apical plasma membrane, as well as in basolateral granules of the proximal convoluted tubule cells. THP immunoreactivity was seen in the epithelial cells lining the thick ascending limb of the loop of Henle. Furthermore, THP was displayed in a scattered pattern within the distal convoluted tubules. The co-localization of megalin and RBP coincides with biochemical studies that have shown megalin to be responsible for renal RBP absorption in the proximal convoluted tubules after filtration through the renal glomerulus. The presence of THP, the carrier for vitamin A in canine urine, showed that vitamin A excretion in the urine of dogs is not merely a filtration process but also seems to be a pathway located in the distal part of the nephron.  相似文献   

7.
Although we recently clarified sex-based differences in mouse kidney morphology, the developmental processes responsible for these gender differences during maturation remain unclear. The present study analyzed the morphometry of kidneys from 20-, 30-, 50-, 60-, 70-, 90-, 120- and 150-day-old DBA/2Cr mice. Total kidney weight and ratio of kidney weight to body weight were larger in males than females beginning at 50 days of age. The percentage of renal corpuscles exhibiting a cuboidal parietal layer was higher in males than in females in the 70-day and older mice. The diameter of cortical renal corpuscles was larger in males than in females beginning on day 90. The number of proximal convoluted tubular cell nuclei was higher in females than in males from day 90 onward. Vacuolar structures in the proximal convoluted tubular epithelium became prominent in 70-day-old males. PAS-positive granules in the proximal straight tubular epithelium became prominent in females on day 50. This paper is the first to describe the development of gender differences in mouse kidney morphology.  相似文献   

8.
Under physiological conditions canines transport vitamin A in blood plasma primarily as retinyl esters bound to lipoproteins and excrete substantial amounts of vitamin A as retinol and retinyl esters with urine. In the aqueous environment of urine, the hydrophobic vitamin A has to be associated with a protein. This vitamin A-protein complex was purified to homogeneity, prepared by preparative ultracentrifugation (density 1.21 g/mL), native polyacrylamide gel electrophoresis (PAGE) and size exclusion chromatography. The vitamin A-protein complex has a high molecular mass of > 5,000 kDa under native conditions. SDS PAGE under reduced conditions revealed a single band with a molecular mass of about 100 kDa for the protein moiety. Peptides obtained after limited proteolysis with trypsin from the 100 kDa protein were characterised by MALDI-TOF mass spectrometry and showed amino acid sequence homology to the human Tamm-Horsfall Protein (THP). This was further confirmed by a positive immunoreaction of the isolated protein with crossreacting human THP antibodies. The localisation of THP in dog kidneys was determined by using immunohistology. The reaction was strong along the entire thick ascending limb ofthe Henle loop and distal convoluted tubule. Our data point to the possibility that THP functions as a novel carrier for vitamin A in the urine of canines.  相似文献   

9.
Measurement of total urinary proteins in individuals that tested positive by urinary dipstick is a typical method for assessing the presence of potentially serious renal disorders. In the absence of such overt proteinuria, however, measurement of specific urinary proteins may be useful in the diagnosis of nephropathies and may provide greater insight into the pathogenesis. The urine of 28 dogs (16 with renal disease and 12 healthy) was evaluated to determine whether specific low-molecular-weight proteins or the pattern of protein excretion could also be used as a marker of tubular dysfunction in dogs. Specific proteins were assessed by immunological methods, whereas protein profiles were determined by surface-enhanced laser desorption/ionization time-of-flight mass spectrometry (MS). In particular, changes in the excretion of retinol-binding protein (RBP) and Tamm-Horsfall protein (THP) appear to be of clinical relevance in the diagnosis of canine kidney diseases. The pattern of urinary protein and peptides revealed specific changes in abundance in dogs with renal disease at molecular masses (kD) of 11.58, 12.41, 12.60, 14.58, 20.95 (RBP), 27.85, and 65.69 (albumin). In conclusion, comparable proteins as in humans might be used as urinary markers for proximal (RBP) and distal (THP) tubular dysfunction in dogs. Surface-enhanced laser desorption/ionization time-of-flight MS is a promising tool for the study of kidney physiology and pathophysiology and might aid in the discovery of new biomarkers of renal disease.  相似文献   

10.
The renal pathology and urinary protein pattern of a 14-month-old female Bernese mountain dog with chronic renal failure was investigated. Sodium dodecyl sulphate-polyacrylamid gel electrophoresis and subsequent Western blot analysis of urine showed the presence of heavy and light chains of immunoglobulin, transferrin, albumin, vitamin D-binding protein, transthyretin and retinol-binding protein (RBP), but no excretion of Tamm-Horsfall protein (THP). Histopathological examinations of the kidneys revealed severe membranous glomerulonephritis accompanied by tubular dilatation, tubular atrophy and interstitial fibrosis. The renal expression of megalin, the main endocytic receptor for the re-uptake of proteins in proximal tubules, RBP and THP was reduced or completely absent, indicating severe tubular dysfunction. The identified urinary proteins may be of interest as additional markers for the diagnosis of juvenile nephropathy in Bernese mountain dogs.  相似文献   

11.
RENAL COCCIDIOSIS OF THE HORSE ASSOCIATED WITH KLOSSIELLA EQUI   总被引:1,自引:0,他引:1  
SUMMARY Klossiella equi in the kidney of a horse is described. Gametocytic and sporogonic stages were observed in the epithelium of the collecting tubules in association with schizonts in the glomeruli and proximal convoluted tubules. The condition was asymptomatic and caused only minor renal damage and inflammation.  相似文献   

12.
13.
Claudin-16 is one of the tight junction protein claudins and has been shown to contribute to reabsorption of divalent cations in the human kidney. In cattle, total deficiency of claudin-16 causes severe renal tubular dysplasia without aberrant metabolic changes of divalent cations, suggesting that bovine claudin-16 has some roles in renal tubule formation and paracellular transport that are somewhat different from those expected from the pathology of human disease. As the first step to clarify these roles, we examined the expression and distribution of claudin-16 and several other major claudin subtypes, claudins 1-4 and 10, in bovine renal tubular segments by immunofluorescence microscopy. Claudin-16 was exclusively distributed to the tight junction in the tubular segment positive for Tamm-Horsfall glycoprotein, the thick ascending limb (TAL) of Henle's loop, and was found colocalized with claudins 3, 4, and 10. This study also demonstrates that bovine kidneys possess segment-specific expression patterns for claudins 2-4 and 10 that are different from those reported for mice. Particularly, distribution of claudin-4 in the TAL and distal convoluted tubules was characteristic of bovine nephrons as were differences in the expression patterns of claudins 2 and 3. These findings demonstrate that the total lack of claudin-16 in the TAL segment is the sole cause of renal tubular dysplasia in cattle and suggest that the tight junctions in distinct tubular segments including the TAL have barrier functions in paracellular permeability that are different among animal species.  相似文献   

14.
Glycated proteins are considered as one of the factors involved in the pathogenesis of diabetic complications, including nephropathy. These proteins are formed endogenously under conditions of hyperglycemia, as well as being provided with food containing sugars, which was subjected to high temperature. Examples are egg products. One of the proteins found in eggs in a relatively high concentration is chicken cystatin (ovocystatin). It is now believed that some proteins can passage the intestinal epithelium by transcytosis directly into the bloodstream. Thus, glycated protein present in food can be an additional source of glycotoxins. The aim of this study was to compare the affinity of native and glycated cystatin to the brush border membranes of rat kidney. Kinetic analysis was performed with surface plasmon resonance technique using sensor chip L1. Dissociation constants for native and glycated cystatin (Kd) were 2.76 μmol/L and 3.82 μmol/L, respectively. The results of our study indicate that glycation only slightly affects binding of cystatin to brush border membranes. This suggests that glycated cystatin and other glycated proteins may also be efficiently taken up in the kidney proximal tubule. The observation may be important for understanding the mechanisms involved in the development of diabetic nephropathy.  相似文献   

15.
The purpose of this study was to investigate the influence of feeding and UVB exposition on the occurrence and distribution patterns of vitamin D receptors (VDR) and calbindin D28k (Cb‐D28k) in the gastrointestinal tract of veiled chameleons. Thus, 56 veiled chameleon hatchlings were divided into six treatment groups: UV (with UVB exposure); No (no supplements, no UVB exposure); CaAUV (with calcium (Ca), vitamin A supplementation, UVB exposure); CaA (with Ca, vitamin A supplementation); CaADUV (with Ca, vitamin A, vitamin D supplementation, UVB exposure); and CaAD (with Ca, vitamin A, vitamin D supplementation). Animals were reared under the suspected conditions for 6 months on locust‐based diets. Tissue samples of stomach, duodenum, ileum and colon were taken, and semi‐quantitative immunohistochemical methods (IHC) were performed to detect Cb‐D28k and VDR. VDR immunoreactions were higher in the luminal epithelium of the duodenum than in that of the ileum. VDR immunoreactions in the luminal epithelium were higher at the base of the villi of the duodenum as compared to the tip. Cb‐D28k immunoreactions were mainly observed in the luminal epithelium of the duodenum. The two groups treated with all dietary supplements (CaADUV, CaAD) exhibited a higher Cb‐D28k immunoreaction as those with no supplements and UVB exposure only. No immunoreaction for both proteins could be detected in the stomach. This study suggests that the duodenum plays an important role in the active transcellular absorption of Ca in veiled chameleons as shown by the immunohistochemical detection of VDR and Cb‐D28k. Expression of Cb‐D28k, in particular, appears to be regulated by dietary supplementation of vitamin D and vitamin A. VDRs, however, tended to be upregulated when animals were not supplemented with Ca, vitamin D and vitamin A. This may be due to the decreased Ca concentrations which caused vitamin D activation in the skin without any supplementation, but UVB exposure.  相似文献   

16.
Acute kidney injury (AKI) is a life-threatening condition for which an early diagnosis is problematic. The aim of the present study was to identify kidney-derived urinary proteins specific to AKI in sheep. AKI was induced in six sheep by an overdose of ketoprofen. Six untreated sheep served as controls. Urine samples were collected for up to 24 h after drug administration and pooled according to time and treatment. Tissue samples from kidney were taken immediately after euthanasia. Urinary proteins were separated by two-dimensional gel electrophoresis (2DE) and the proteins of interest were identified by mass spectrometry. Calbindin-D28k, retinol-binding protein 4 and CD1d were identified in ketoprofen-treated sheep, but not in controls. In addition, calbindin-D28k and CD1d were localized in kidney tissues by immunohistochemical staining. These preliminary results suggest that urinary calbindin-D28k and CD1d represent potential useful biomarkers of AKI, at least in sheep.  相似文献   

17.
Morphological studies to localize mast cells in the wall of the convoluted and straight parts of the proximal tubules of the domestic swine kidney were performed. Kidney perfusion was carried out in 8-month-old pigs and semi-thin and ultrathin sections were prepared after a routine treatment. A light microscopic study showed that mast cells were not frequently found. Most were localized in the wall of the proximal convoluted tubule, while in the proximal straight tubule wall they were fewer in number. Most of the mast cells were oval in shape, their size being typical for this species, and the granules were reddish in colour. Three types of granule containing an evenly distributed granular-fibrous substance were found by TEM examination: the first type had a single electron-optically dense belt under the membrane; the second showed optically empty spaces between the substance and the cell membrane; the granules from the third type had two parallel dense belts below the granular membrane and were the smallest in size. Some of the granules of the first type were connected with the granular endoplasmic reticulum. A very narrow intercellular area and single desmosome-like junctions were found between the mast cells and the epithelial cells. Protrusions of plasmalemma and granules outside the cells were not established. On the basis of these results and data from the scientific literature, a comparative analysis was carried out. This showed certain differences between the results obtained and previous findings on the morphology of domestic swine mast cells and granules.  相似文献   

18.
1. Using the proximal convoluted tubule of the fowl kidney as indicator tissue the immersion application of fixatives of differing composition and osmolality was studied. 2. The best results were obtained with Dalton's buffered osmium tetroxide and with sodium cacodylate buffered glutaraldehyde followed by osmium post-fixation. 3. The most satisfactory component concentrations in both cases were those which most reproduced a total osmolality close to that of fowl plasma. With both types of fixation the ultrastructural image of the kidney tubule was sensitive to changes in fixative osmolality and differences were clearly identified over a 30 to 50 mOsm range. 4. With glutaraldehyde/osmium double fixation it was found that it was the total osmolality of the glutaraldehyde buffer combination that was to be considered in a study of osmolotic effects, not the osolality of the buffer vehicle alone. 5. The 30 to 50 mOsm difference in fixative osmolality that was able to be detected by studying the image of the kidney tubule was of the order of magnitude commonly experienced as experimental error in the laboratory as a result of changes in reagent batches or error in making up the solutions. The measurement of osmolality therefore provides an ideal quality control to the laboratory make-up of fixative solutions.  相似文献   

19.
为了解犊牛磺胺中毒的病理形态学变化特点,对2头因磺胺中毒而死亡的犊牛进行了详细的病理学研究.结果表明,犊牛磺胺中毒的病理性损伤主要发生于肾脏和肝脏.宏观检查可见,肾脏肿胀,色泽变淡,皮质增宽,肾盂有多量豆腐渣样物质.肝脏肿胀,淡橘红色,质地脆易碎.微观检查可见,近曲小管上皮细胞肿胀,核浓缩,染色不良,大量上皮细胞脱落....  相似文献   

20.
To understand the neurochemical properties of the gastric myenteric plexus of ruminants, the expression patterns of calbindin D-28k (CB), calretinin (CR), substance P (SP) and calcitonin gene-related peptide (CGRP) were explored in the Korean native goat. In gastric myenteric plexus, CB and SP immunoreactivity were observed in round- or oval-shaped neurons. CR and CGRP immunoreactivity were detected only in the nerve fibers. This immunohistochemical localization of CB, CR, CGRP and SP in the myenteric plexus of the goat stomach exhibited species-specific patterns. These findings suggest that these substances may be directly or indirectly related to the gastric functions of the goat stomach.  相似文献   

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