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Query: UMLS:C0403608 (ureter)
 9,655 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Renal cortex homogenates from aged (greater than 5 y) rabbits showed decreased specific activities of brush border membrane enzymes compared to those from control young (6 m) rabbits but the specific enzyme activities of basolateral membrane, endoplasmic reticulum and mitochondria did not differ between the two groups. The stimulatory effects of parathyroid hormone (PTH) on the Ca(2+)-pump enzyme [(Ca(2+)+Mg2+)-ATPase] activity in kidney cortex homogenates were markedly less in aged rabbits, but the effect of cAMP on this enzyme activity was similar. Moreover, the production of cAMP induced by PTH was markedly less in the renal cortex homogenates from aged rabbits. From these results, we have proposed the following mechanism; aging--decrease in the response of cAMP to PTH in renal cortex--decrease in the stimulatory effect of PTH via cAMP on the Ca(2+)-pump enzyme--decreased reabsorption of Ca2+ from ureter--increased urinary Ca2+ secretion. This pathway may contribute to the worsening of senile osteoporosis.
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PMID:Effects of aging on renal response to parathyroid hormone in vitro. 135 71

An antibody against rat kallikrein was produced in rabbits and its localization was studied in various organs of the rat to confirm its specificity. The distribution of immunoreactive kallikrein was studied in rat ureter by use of immunochemical techniques. Ureteral tissue was fixed in Zamboni's-glutaraldehyde fixative and immunostained with indirect immunofluorescence and the peroxidase-antiperoxidase (PAP) method for light and electron microscopy. Preabsorption of the primary polyclonal antiserum with purified rat urinary kallikrein and substitution with normal serum were used as controls. By light microscopy, kallikrein was localized in the lamina propria and in the adventitial connective tissue surrounding the entire ureter. Immunoelectron microscopy confirmed this immunolocalization. Immunoreactive kallikrein was concentrated in fibroblasts of connective tissue and was not present in collagen fibers. Immunoreactivity was associated with the Golgi complex, free polyribosomes, and rough endoplasmic reticulum. No immunostaining was observed in other subcellular components of fibroblasts.
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PMID:Localization of a renal kallikrein immunoreactive-like substance in rat ureter. 305 70

The cells of the basal layer of the ureter epithelium of senile rat have been studied by means of thin section electron microscopy. One of the main features of these cells was the presence of paracrystalline structures within unusually long mitochondria (megamitochondria). The detailed study of these structures showed that they were produced by the mitochondrion itself through alterations of one or two longitudinally oriented cristae. The megamitochondria were completely surrounded by membranes of rough endoplasmic reticulum, frequently showed lipid lamellae at one end, and were always situated in the vicinity of the nucleus. The possible morphogenetic mechanisms of the paracrystalline structures are discussed.
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PMID:Atypical cristae (paracrystalline inclusions) in mitochondria of epithelial cells of the rat ureter. I. Ultrastructural features. 632 22

Upper excretory pathway musculature was studied by electron microscopy, both at the level of the obstruction and proximally. Two types of lesion were investigated: pyelo-ureteral junction anomalies and primary obstructive mega-ureter. Two types of muscle cell are recognized in the excretory pathway walls, typical and atypical cells, the latter being considered as possessing pace-maker activity and constituting almost total population of muscles of calices and pelvis. However, they were few in number in the pyelo-ureteral region and were practically absent from the ureter. Various conclusions can be drawn from the findings in this study. Both typical and atypical cells are modified in the obstructed upper excretory pathways. Ultrastructural appearances of lesions are identical at the site of an proximal to the obstruction. Modifications in these cells were: a rich sarcoplasmic reticulum, an increase in number of mitochondria and glycogen particles, disorganized distribution of contractile or cytoskeletal filaments, altered contact zones between contiguous smooth muscle cells, increased richness of granular endoplasmic reticulum and excessive development of the Golgi apparatus. More chronic lesions show enhanced fibrosis with reduced muscle contractility, the fibrosis affecting mainly elastic fibers in young patients and collagen fibers in more elderly subjects. The development of fibrosis may be due to changes in the granular endoplasmic reticulum and the Golgi apparatus. From the practical point of view, increase in fibrosis with duration of course of obstruction is an argument for as early as possible surgical intervention.
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PMID:[Ultrastructural modifications of the tunica muscularis in congenital obstruction of the upper urinary tract. Physiopathological interpretations and anatomo-clinical correlations]. 649 59

The construction of renal lobules in Triturus (Cynops) pyrrhogaster was studied by reconstruction from serial semithin sections, and the structure of nephrons, collecting ducts and ureters was investigated by means of light and electron microscopy. In T. pyrrhogaster the kidney was mesonephros in construction; renal lobules were arranged segmentally and each of them sent one ureter. Male ureters ran caudally and met together before joining the Wolffian duct. In renal lobules, long collecting ducts ran medio-laterally in the dorsal aspect of the kidney and sent several branches ventrally. Each branch duct or short collecting duct received one nephron. Each nephron had five segments; 1) renal corpuscle, 2) ciliated neck segment with or without a naphrostome, 3) proximal tubule, 4) ciliated intermediate segment and 5) distal tubule. Proximal and distal tubules were segregated spacially in renal lobules and occupied the peripheral and central zone respectively. The filtration barrier of the glomerulus consisted of both the basal lamina of podocytes and the subendothelial connective tissue, and was much thicker than the mammalian filtration barrier. Proximal tubule cells had a brush border, apical specialization for reabsorption of organic materials and well-developed smooth endoplasmic reticulum, but few baso-lateral interdigitations. In distal tubule cells, baso-lateral interdigitations and infoldings were well-developed. Collecting duct cells had a sparse cytoplasm. Ureter cells in males contained many secretory granules. On the basis of structural organization of the newt kidney as well as physiological data in literature, we suggest that in land vertebrates proximal tubules were primarily adapted to reabsorption of organic materials and distal tubules to reabsorption of electrolytes and water.
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PMID:The structure of the kidney of Japanese newts, Triturus (Cynops) pyrrhogaster. 683 32

Light and electron microscopic techniques were employed to study the structure of the ureter of the starling (Sturnus vulgaris). Particular attention was paid to the characterisation of the epithelial cell types. Differences were found in the chemical composition of the mucins found in the ureteric epithelial cells and the medullary collecting ducts, which suggested that they might perform different functions. The epithelial cells were of two main types. The basally situated cells were electron-lucent, apparently relatively undifferentiated, and contained little rough endoplasmic reticulum or mucigen. The cells which were directly adjacent to the lumen were highly specialised for mucus secretion and contained extensive rough endoplasmic reticulum and large numbers of mucigen-containing vacuoles. Cells of intermediate character were also observed and the relationships between the epithelial cell types were discussed. The possibility of a holocrine mode of mucus secretion in the avian ureteric epithelium was discussed.
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PMID:The histology and fine structure of the ureter of the European starling (Sturnus vulgaris). 688 20

The male ACI rat has a congenital Wolffian duct defect manifested by unilateral agenesis of the kidney, ureter, seminal vesicle, ductus deferens, and most of the epididymis. In the adult the testis on the affected side is markedly smaller than the contralateral testis and spermatogenesis is absent. In addition, in vitro perfusion of the affected testis revealed significantly less testosterone secretion than did the contralateral testis. Moreover, electron microscopy revealed that the smooth endoplasmic reticulum of the Leydig cell was significantly decreased. Thus, the affected testes clearly showed deranged spermatogenesis and Leydig cell structure and function. The ACI rat model may provide insight into the potential effects of congenital epididymal abnormalities on the testis of the human.
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PMID:Testicular atrophy associated with agenesis of the epididymis in the ACI rat. 705 91

Five surgical specimens of pelvi-ureteric junction from idiopathic hydronephrotic kidneys were obtained according to the Anderson-Hynes technique and were examined under an electron microscope. Fibrosis and marked alterations of several muscle cells were observed throughout all the specimens. Muscle cell alterations were different form cell to cell, namely: a noticeable development of the rough endoplasmic reticulum and of the Golgi apparatus, a great number of glycogen particles, a wide extension of the smooth endoplasmic reticulum and a disorganization of the filament pattern. The aforementioned alterations could be observed both in 'special' and 'typical' muscle cells; moreover, a reduction in the number and extension of cell-to cell junctions was observed in 'special' muscle cells only. It could be guessed that the modifications observed in the muscle cells and the fibrosis are responsible for the altered motile activity of the upper urinary tract and led to the clinical manifestations of idiopathic hydronephrosis. However, the muscle cell malfunction is probably extended more than in the surgically resected specimens, as in the patients studied it was documented by urodynamic data that the urine flow through the ureter was due to be a wide pelvic-ureteric plasty more than an effective peristaltic contraction of the upper urinary tract.
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PMID:Some ultrastructural aspects of human pathological pelvi-ureteric junction in idiopathic hydronephrosis. 714 20

Muscle coat specimens from human calices, renal pelvis, pelvi-ureteric junction, upper, middle and lower ureter segments were examined under an electron microscope. These specimens were taken from 8 patients who had undergone nephroureterectomy: 6 for localized renal carcinoma and 2 for papillary tumor of the pelvis. Two types of smooth muscle cells were observed, "typical" muscle cells and "special" muscle cells. The latter are rich in agranular endoplasmic reticulum, have few myofilaments and are interconnected in numerous, extended, peculiar contact areas. The ratio between these two types of muscle cells differs as also does their innervation between the various segments examined. On the basis of our findings we propose that the "special" muscle cells perform a "pacemaking" function.
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PMID:Ultrastructure of the urinary tract muscle coat in man. Calices, renal pelvis, pelvi-ureteric junction and ureter. 720 55

The renal origin of kallikrein is now clearly established. However, the presence of kallikrein in urine raises questions about a possible physiological role of this enzyme at the urinary level. We have already demonstrated the presence of kallikrein-like substance in rat ureter. For establishing the continuity of the presence of kallikrein-like substance along the urinary tract we have studied the localization of immunoreactive kallikrein-like substance in urinary bladder of the normal rat by immunohistochemical methods for light- and electron-microscopy, using an antibody against rat urinary kallikrein. By light microscopy, kallikrein-like substance was found to be associated with the lamina propria, which is the connective tissue component which constitutes one layer of the bladder wall. Weak staining was present in the smooth-muscle layer. By immuno-electron microscopy, kallikrein-like substance was localized in fibroblasts which were present in the connective tissue and which penetrated into the layer of smooth muscle; immunoreactivity was observed in endoplasmic reticulum, Golgi apparatus and free polyribosomes. Immunolabelling was demonstrated in no other part of the wall bladder and in no other cellular component. The continuity of the presence of kallikrein-like substance from the kidney to the urinary bladder gives new indications concerning the significance of this system in renal physiology.
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PMID:Immunolocalization of renal kallikrein-like substance in rat urinary bladder. 769 24


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