Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P41181 (collecting duct)
 5,183 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The functions of a kidney, whether normal or cystic, can be conceptualized in terms of anatomy (glomerulus, proximal tubule, loop of Henle, distal convolution, and collecting duct), activity (volume regulation, dilution and concentration, acid-base regulation, potassium excretion, transport of organic molecules, and calcium and phosphate excretion), and the integration of anatomic organization to meet functional demand. Our discussion of renal cystic disorders follows this conceptual outline. For discussions of normal renal physiology, the reader is referred to any one of several recent, excellent reviews (1-3). Systematic evaluation of renal function in cystic diseases of the kidney (medullary sponge kidney, medullary cystic disease, and polycystic kidney disease) has only rarely been performed. The available information suggests that the earliest detectable lesions consist primarily of tubular dysfunction. With time, however, significant reduction of glomerular filtration occurs and the resultant accumulation of uremic toxins dominates the clinical picture in polycystic and medullary cystic disease. Significant changes in glomerular function are unusual in medullary sponge kidney. This review represents an attempt to summarize the large body of literature that has accumulated on functional abnormalities in these disorders, and to point out those areas where further investigations are needed.
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PMID:Functional abnormalities in renal cystic diseases. 0 65

The C57BL/6J-cpk mouse has a form of autosomal-recessive polycystic kidney disease characterized by the rapid growth of large collecting duct cysts and the development of severe renal failure usually by three to four weeks of age. Previous studies had shown higher steady-state levels of proto-oncogene mRNA in these cystic kidneys. It is now shown using nuclear run-on transcription that the c-fos and c-myc proto-oncogenes are transcribed at higher rates in cystic kidneys, and thus that increased transcription, in part, may account for the increased mRNA levels. c-myc mRNA was detected by in situ hybridization in nephron anlagen and elongating tubules of normal and cystic kidneys during late fetal and early neonatal kidney development. Localization of c-myc expression in the normal kidney decreased with age over the three-week postnatal period. By contrast, c-myc mRNA was found in cysts as early as three days of age, with increased levels at two and three weeks. c-myc expression was also elevated in apparently normal, non-dividing proximal tubules in three-week-old cystic animals. On the basis of these findings, we suggest that c-myc expression is linked to the proliferation of cells engaged in the primary cystogenic process, and that expression of this gene in proximal tubule cells of severely azotemic animals reflects the compensatory response of residual tubular epithelial cells to progressive renal dysfunction.
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PMID:Localization of overexpressed c-myc mRNA in polycystic kidneys of the cpk mouse. 155 5

The usefulness of various segment and cell-type specific antibody, lectin and functional markers in the study of cystic renal lesions was evaluated. For this purpose, kidneys from recessive polycystic kidney disease (RPKD), thought to involve mainly the collecting ducts, and cystic kidneys of Meckel's syndrome (MS), which show dilation randomly along the nephron, were studied. The segment (and differentiation-stage)-specific anti-brush-border (specific for proximal tubules) antibodies stained morphologically normal proximal tubules, failed to react with cyst wall epithelium in RPKD, but readily stained some cysts in MS. Immunostaining for Tamm-Horsfall glycoprotein (distal tubules) similarly revealed normal tubular profiles, and also stained moderately dilated tubules, but not the large cysts in either disease type. Lectin markers of the distal tubules and collecting ducts (peanut agglutinin, Helix pomatia agglutinin and Dolichos biflorus agglutinin) reacted with both dilated tubules and with the cyst walls in RPKD and Meckel kidneys, suggesting that in RPKD, the dilations also occur in the distal nephron in addition to the collecting duct, and in MS in any part of the renal tubule. The cell type-specific functional marker of the collecting duct, anti-NaK-ATPase reactivity (found in principal cells) could be seen in RPKD but not in Meckel kidney cysts, suggesting a minor involvement of principal cells in MS. Consistent with this, only occasional carbonic anhydrase (found in intercalated cells) or band 3 (bicarbonate-chloride exchanger molecule of intercalated cells) of collecting ducts positive cells in the cysts could be seen, suggesting that intercalated cells are only sparsely seen in these lesions. The results show the usefulness of a panel of independent markers in studying the segment, cell-type and function-specific features of renal cystic lesions as a basis for their classification.
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PMID:Polycystic disease of the kidney. Evaluation and classification based on nephron segment and cell-type specific markers. 169 Mar 15

Polycystic kidney disease (PKD) represents a form of renal epithelial hyperplasia. The C57BL/6J-cpk mouse, which has an infantile form of PKD, has a dramatically reduced expression of renal prepro-epidermal growth factor (EGF) mRNA and immunoreactive protein. Since EGF promoted maturation of epithelia in the neonate, the relative lack of renal EGF may contribute to the development of the collecting duct cysts by delaying epithelial maturation.
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PMID:Murine infantile polycystic kidney disease: a role for reduced renal epidermal growth factor. 171 Apr 22

We evaluated the characteristics of renal lesions in rat autosomal recessive polycystic kidney (ARPK). In rat ARPK, small cysts appeared primarily in the medulla 2 months after birth and gradually extended to the cortex, forming large cysts involving the entire layer after 8 months. By immunofluorescence microscopy, type IV collagen was more strongly stained in the epithelial basement membrane of the rat ARPK than in the normal rat tubular basement membrane (TBM). Electron microscopy demonstrated a marked thickening, slight splitting and lamination of the TBM in the ARPK. As peroxidase-labeled lectins, dolichos biflorus very strongly stained the cyst epithelium whereas lens culinaris did not. These findings indicate that cysts in rat ARPK originate in the collecting duct.
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PMID:Autosomal recessive polycystic kidney in rats. 172 66

Sulfated glycoprotein-2 (SGP-2) is a secreted, dimeric, glycosylated protein synthesized by a number of different epithelial cell types. Although its function is not yet understood, SGP-2 has been hypothesized to be involved in such diverse processes as the promotion of cell-cell interactions, spermatogenesis, modulation of the complement system, and programmed cell death. We have now found that the SGP-2 gene is developmentally regulated in the mouse kidney. SGP-2 gene expression is first detected in the condensing nephrogenic mesenchyme and is subsequently down-regulated during the maturation of the glomerular epithelia, proximal tubules, and collecting ducts. SGP-2 continues to be expressed in the mature kidney in distal tubules and in the urothelial lining of the calyx and papilla. We have also examined the expression of the SGP-2 gene in polycystic kidneys of the C57BL/6J-cpk mouse, a model of autosomal recessive polycystic kidney disease in which there is development of epithelial-lined cysts arising primarily from the collecting duct system. Abnormally high levels of SGP-2 mRNA were found in the cyst wall epithelium of polycystic kidneys. The expression of the SGP-2 gene in normal development suggests that it plays a role in differentiating epithelial structures; and the abnormally high levels of SGP-2 gene expression in polycystic kidneys suggests that the cells lining cysts are not fully differentiated. It is possible, therefore, that polycystic kidney disease is caused by a defective developmental process in which there is a delay in terminal differentiation.
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PMID:The SGP-2 gene is developmentally regulated in the mouse kidney and abnormally expressed in collecting duct cysts in polycystic kidney disease. 186 65

There are two known forms of hereditary polycystic kidney disease (PKD) in humans. Although both forms initiate early in life, autosomal recessive PKD is rapidly progressive to kidney failure shortly after birth whereas autosomal dominant PKD is slowly progressive, taking many years to end stage. Research in this field has been limited by the availability of suitable animal models of PKD. Recently the C57BL/6J-cpk mouse has been used to study the pathogenesis of rapidly progressive hereditary PKD. The study presented here describes a slowly progressive PKD in the DBA/2-pcy mouse. The disease trait is transmitted in an autosomal recessive pattern and was localized to chromosome 9 through linkage to the dilute coat color and transferrin genes. Whereas some cystic changes were seen in fetal and newborn affected mice, renal enlargement did not develop until after 8 weeks of age and azotemia did not develop until after 18 weeks of age. Renal cysts were identified in all segments of the nephron and collecting duct and progressively enlarged with age. Individual cysts were found to be lined by a single layer of epithelial cells in most areas, with focal polyps and mounds of cells principally in collecting duct cysts. Early stages of cyst formation were associated with some abnormalities of tubular and glomerular basement membranes and accelerated eruption of incisors. Late stages of the disease were characterized by azotemia and chronic renal interstitial inflammatory infiltrates in all affected animals and cerebral vascular aneurysms in a few. We conclude that the DBA/2-pcy mouse has a form of renal cystic disease that appears similar in many respects to that seen in the dominant form of human PKD.
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PMID:A hereditary model of slowly progressive polycystic kidney disease in the mouse. 188 68

The C57BL/6J-cpk mouse has an inheritable form of polycystic kidney disease similar to the autosomal recessive disorder seen in humans. Between approximately 1 and 3 weeks of age, affected cpk mice develop numerous large cysts in the collecting tubule segment of kidney nephrons. The present study examined the ontogeny of renal and submandibular gland prepro-epidermal growth factor (preproEGF) gene expression in the cpk mouse using Northern blot hybridization and immunohistochemistry. There was a virtual absence of renal preproEGF gene expression in cystic kidneys over the 3-week postnatal period, during which time renal preproEGF mRNA and proEGF/EGF protein normally reach significant levels. PreproEGF mRNA was expressed in salivary glands of cystic mice; however, this mRNA could not be further elevated with testosterone suggesting that there are abnormalities in the regulation of the preproEGF gene in the submandibular gland, as well as in the kidney. Since renal preproEGF expression during the early postnatal period occurs when collecting duct cysts form, it is possible that a deficiency in renal proEGF or EGF contributes to the rapid development of collecting duct cysts and the concomitant renal failure in the C57BL/6J-cpk cystic mouse.
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PMID:Defective epidermal growth factor gene expression in mice with polycystic kidney disease. 196 5

Histochemical techniques utilizing Tetragonolobus lotus (proximal tubules), Arachis hypogaea (distal nephron, i.e., distal convoluted tubules and collecting ducts), and antibodies against Tamm-Horsfall protein (thick ascending limbs of Henle) were used to determine the site of origin of renal cysts in five children with autosomal recessive polycystic kidney disease (ARPKD) and three patients with glomerulocystic disease (GCD) presenting in the 1st year of life. The findings support a distal nephron origin for the cysts in the children who had ARPKD, whereas the majority of cysts in the children with GCD were confirmed as having a glomerular origin. Tamm-Horsfall protein was identified in the cysts of both ARPKD and GCD; this finding suggests free communication between some of the cysts with the thick ascending limb of Henle. An unexpected finding was the frequent presence of cysts surrounded by muscle fibers. We suggest that these cysts are of collecting duct origin.
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PMID:Renal cystic disease of infancy: results of histochemical studies. A report of the Southwest Pediatric Nephrology Study Group. 270 85

We studied the kidneys from ten patients with adult (autosomal dominant) polycystic kidney disease (APKD) stained with lectins specific for different segments of the nephron on 20 cysts from each case (ranging in size from 0.1 to 1.3 cm in nine cases and from 1.5 to 6 cm in one case). The epithelium of all cysts with positive reactivity (Arachis hypogaea and epithelial membrane antigen) was of collecting duct origin. Many cysts remained unstained. Cysts of proximal tubule origin could not be identified using the specific lectin Lotus tetragonolobus. Focal epithelial hyperplasia appeared in the collecting duct cysts. Cysts surrounded by smooth muscle were frequent and considered to be of collecting duct origin. One case had glomerular cysts. We conclude that the cysts of APKD are principally of collecting duct origin.
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PMID:Histogenesis of the renal cysts in adult (autosomal dominant) polycystic kidney disease: a histochemical study. 306 82


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