Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0403608 (ureter)
 9,655 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Monoclonal antibodies against basement membrane (BM) were generated using the matrix deposited by cultured rabbit corneal epithelial cells as immunogen. BM antibodies were identified by immunofluorescent staining of frozen tissue sections and of extracellular matrix of living cultured cells. BM localization was confirmed by immunoelectron microscopy. Antibody AE26 immunoprecipitates a 140,000 Mr component from radiolabeled corneal epithelial cells and recognizes this component plus a 95,000 Mr band on Western blots. The antigen resists extraction by high and low salt and by nonionic detergents, but is solubilized in 4 M urea/1% mercaptoethanol. On isoelectric focusing and nonequilibrium pH gradient gels, AE26 antigen migrates to the acidic region (pI less than 3). The molecule is destroyed by trypsin, but is insensitive to bacterial collagenase. In frozen tissue sections, AE26 stains only BM of stratified epithelia plus trachea, ureter, lung, and intestine, but no other epithelial or nonepithelial BM. AE26 antigen is detected on Western blots of cornea, skin, and lung extracts, but not liver, kidney, or muscle, indicating that this is not due to masking of the epitope. This tissue distribution is different from any previously described BM molecule. Although we have not ruled out the possibility that AE26 recognizes a modification or fragment of a known BM component (particularly entactin), the acidic pI, collagenase resistance, and unusual tissue specificity suggest that AE26 recognizes a new BM protein. The BM heterogeneity demonstrated by AE26 may play a structural role or provide positional signals to the overlying epithelium.
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PMID:Tissue-specific distribution of a novel component of epithelial basement membranes. 219 81

Endogenous glycosaminoglycans probably have a protective effect in the urinary tract, e.g. against stone formation. The synthetic sulphated polysaccharide pentosanpolysulphate (PPS) has been suggested to exert a similar protective effect e.g. by inhibition of crystallization and bacterial anti-adhesion. We have studied the distribution in rats of tritium-labelled PPS. Chromatography showed this material to contain two distinct peaks with approximate molecular weight around 2.700 (60-70%) and 1.000 (30-40%) daltons. PPS was administered orally and intravenously (5 mg/kg b.wt.) to Sprague-Dawley rats, which were killed 1 and 4 hours later, respectively, and subjected to whole-body autoradiography. Autoradiograms of sections from intravenously injected rats showed an extensive distribution of radioactivity in the whole animal, with a notable labelling of connective tissues, while bone and cartilage had low activity. There was upper intestine activity, suggesting some hepatic excretion. The most conspicuous finding, however, was the high concentration in urine and a preferential localization of activity corresponding to the lining of the urinary tract (pelvis, ureter, and bladder). The distribution was similar, but the activity lower after oral administration. In one experiment, PPS was applied intravesically under anaesthesia, with and without epithelial destruction caused by instillation of 0.4 M HCl. After vigorous rinsing, with saline, the radioactivity was still retained in the bladder wall. In other intravenous experiments, the bladder was extirpated, everted and rinsed in saline or urea of increased osmolality. High amount of radioactivity could be rinsed off by 0.5 M saline. Chromatography of the rinsing solution showed presence of both fractions of PPS previously found in the injection solution.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Preferential localization of 3H-pentosanpolysulphate to the urinary tract in rats. 244 5

To elucidate the role of the ureter in urinary concentration we studied the effect of partial and complete ureteral excision on urinary osmolality and papillary interstitial osmolality and on sodium, potassium, and urea concentrations in the antidiuretic rat. Urine and descending vasa recta (DVR) plasma samples were obtained by micropuncture of the left renal papilla before (period 1) and 45 min after (period 2) complete (group 1, n = 10 rats) or partial (group 2, n = 10 rats) ureteral excision. Urine osmolality fell from 2,063 +/- 156 (mean +/- SE) to 736 +/- 116 mosmol/kgH2O after complete ureteral excision (P less than 0.01). After partial ureteral excision, the fall was less than half as great, from 2,038 +/- 167 to 1,551 +/- 162 mosmol/kgH2O (P less than 0.01). Vasa recta plasma osmolality decreased from 1,742 +/- 133 to 860 +/- 119 mosmol/kgH2O after complete excision (P less than 0.01) but only from 1,830 +/- 146 to 1,504 +/- 154 mosmol/kgH2O after partial excision (P less than 0.05). Mean DVR plasma sodium concentration declined from 339 +/- 25 to 211 +/- 25 meq/l (P less than 0.01) in group 1 but did not change in group 2 (348 +/- 21 to 347 +/- 28 meq/l). The fraction of DVR plasma osmolality accounted for by urea decreased significantly from 0.59 +/- 0.01 to 0.46 +/- 0.02 mM/(mosmol/kgH2O) in group 1 and from 0.59 +/- 0.02 to 0.49 +/- 0.03 mM/(mosmol/kgH2O) for group 2 (P less than 0.01, both groups). We interpret these findings to show that the remnant ureter moderates the fall in interstitial osmolality at least in part through preservation of the corticomedullary sodium chloride gradient.
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PMID:Effect of ureteral excision on inner medullary solute concentration in rats. 320 84

We have developed a new method for urine collection in conscious, unrestrained rats through a chronic indwelling ureteral catheter, which allows direct differential sampling of small urine fractions over periods as small as 1 min. The technique was validated in intact and unilaterally nephrectomized rats by cumulative intravenous saline loading. Comparison of kidney with ureter catheter and contralateral kidney (urine collection from the bladder) revealed no differences in glomerular filtration rate and urine production between both kidneys. One week after catheter implantation in unilaterally nephrectomized rats, signs of renal functional disturbance as assessed by glomerular filtration rate, urine concentrating capacity after 24 h water deprivation, and plasma and urinary urea concentrations before and after water deprivation were not detected. Our technique provides a novel tool for direct measurements of short-term changes in urine composition in conscious animals.
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PMID:A new method for collecting urine directly from the ureter in conscious unrestrained rats. 324 94

In order to study the role of the renal pelvis on urea sparing in sheep fed low protein diets, the pelvis was perfused through the ureter with 1M and 3M urea solutions. Eight ewes were used: four on a regular diet (total nitrogen 188.7 g.kg-1 dry matter) and the other four on a low protein diet (total nitrogen 109.4 g.kg-1 dry matter). On each animal, perfusions were performed on one kidney; the other one was kept as a control. Fractional excretion of urea (TEu) and urea (Cu), inulin, para-aminohippurate and osmolar clearances, were determined during five experimental periods of 30 min each (T = control, 1M = perfusion with 1M urea solution, R1 = first period of recovery, 3M = perfusion with 3M urea solution, R2 = second period of recovery). 1. During control periods sheep on low protein diet have a greater capacity of urea retention than sheep on regular diet, under antidiuretic conditions (inulin U/P = 200). The following data (means +/- S.D.) are all reduced in animals on low protein diet: TEu by 36% (0.38 +/- 0.19 vs. 0.59 +/- 0.28 for normal protein sheep, p less than 0.05), Cu by 55% (0.50 +/- 0.19 vs. 1.15 +/- 0.49 ml.min-1.kg-1 for normal sheep, p less than 0.01) and amount of urea excreted by 80% (2.1 +/- 0.7 vs. 10.4 +/- 2.7 mg.min-1 for normal sheep, p less than 0.01). 2. The linear regression analysis of the relationship between tubular reabsorption of urea and its filtered amount shows that the capacity of urea retention is significantly higher in low protein sheep and that the difference between the two groups is greater as the filtered amount increases. Following 1M and 3M perfusions, the capacity of urea reabsorption by the perfused kidneys is significantly decreased in low protein animals whereas there is no change in the normal ones. The result is that perfused kidneys of the low protein sheep increase the amount of urea excreted during these periods: urine concentration of urea (Uu) increases by 55% during R1 and by 144% during R2, TEu increases by 60% during R1 and by 147% during R2 and Cu increases by 40% during R1 and by 95% during R2, without any variation of urine flow rate. These changes could be understood, provided that an important transfer of the perfused urea to the renal medulla in the low protein sheep would reduce the concentration gradients which enhance urea passive reabsorption from the collecting ducts.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:[Kidney retention of urea in sheep on a hypoprotein diet: study by retrograde perfusion of urea in the kidney pelvis]. 325 Oct 40

Sheep fed a low-protein diet reduced renal urea excretion. An important fraction of urea perfused into the renal pelvis via the ureter, is reabsorbed through the pelvic epithelium.
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PMID:[Augmentation of the urea retention capacity of the kidney in protein-deficient sheep: role of the kidney pelvis]. 325 93

It has been hypothesized that urea from the final urine is recycled into the renal papilla through the pelvic epithelium. To test this hypothesis, samples of urine were collected by micropuncture proximally and distally through the intact, contracting ureter of the anesthetized rat. In 12 rats, in which urine flow was 5.89 +/- 0.67 microliter/min (a moderate antidiuresis), the ratio of proximal-to-distal urea concentration, corrected for water movement, was 0.93 +/- 0.03 (P less than 0.01 compared with unity), indicating that approximately 7% of urea in the urine emerging from the terminal collecting duct was reabsorbed by the time it reached the distal ureter. To assess the possible contribution of urea reabsorption by the ureter, the ureter was cannulated proximally and distally and perfused with urine of known composition at 6.26 +/- 0.10 microliter/min. In nine rats, the ratio of urea concentration in the perfusate collected from the distal end of the ureter to that in the perfusate entering the proximal end was 0.93 +/- 0.02 (P less than 0.01 compared with unity), indicating 7% reabsorption. Movement of solute across the ureteral epithelium was not restricted to urea. Potassium and creatinine were also reabsorbed [3.4 +/- 0.9 (P less than 0.01) and 3.5 +/- 1.2% (P less than 0.05), respectively], whereas sodium was secreted [9.2 +/- 2.3% (P less than 0.01)].(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Urea flux in the ureter. 340 82

We report a case of retroperitoneal fibrosis. A 75-year-old man complained of edema of bilateral lower limbs and lumbago. Blood urea nitrogen and serum creatinine were increased. Renal function was improved after he had bilateral percutaneous nephrostomies. Antegrade pyelography showed bilateral hydronephrosis, left ureteral obstruction and medial deviation with narrowing of the right ureter. CT revealed a soft tissue density surrounding the aorta, inferior vena cava and bilateral ureters in the retroperitoneal space. Inferior venocavagraphy displayed stenosis. Bilateral ureterolysis combined with omental sleeve plasty was performed. Post-operatively, the clinical course has continued to be good.
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PMID:[A case of retroperitoneal fibrosis]. 361 33

Serum concentrations of urea and creatinine, urinary clearances of urea and creatinine, and urine concentrating ability have been proposed as measures for determining renal function in patients with urinary diversion through intestinal segments. Intestinal segments reabsorb urinary solutes, including urea and creatinine, complicating these methods of assessing renal function. This study employs a canine model in which urinary clearances of urea, creatinine and inulin are determined through a normal renal unit and ureter and compared with the contralateral renal unit which has had its ureter replaced by a segment of ileum. Urea, creatinine and inulin are reabsorbed by the ileal segment. Reabsorption of each of these solutes is dependent on urinary flow. The clearance of these solutes through the renal unit with the interposed ileal ureter approaches that of the contralateral renal unit under maximal degrees of diuresis. Creatinine and inulin clearances obtained during diuretic states give the most accurate indication of true renal function. These solutes are reabsorbed to a lesser extent than urea. Diuresis minimizes reabsorption of all these solutes by the ileal segment. Urine concentration does not reflect distal tubule function since the ileal segment reabsorbs urinary solutes and is freely permeable to water.
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PMID:Determination of renal function following urinary diversion through intestinal segments. 397 7

These experiments were designed to evaluate the hypothesis that K+ deficiency may be associated with decreased delivery of urea to the renal papillary collecting duct and/or decreased reabsorption of urea from the papillary collecting duct. Either of these factors would result in diminished capacity for urea recycling and might explain the mechanism of the urinary concentrating defect that is observed in K+ depletion. Munich-Wistar rats were fed 25 ml of water and 12 g of normal (CON) or K+-deficient (KD) diet each day for 21 days. Papillary collecting duct samples were obtained by micropuncture through the intact ureter. Fractional delivery of H2O to the base and tip of the papillary collecting duct was increased in KD as compared to CON rats (1.50 +/- 0.30% in KD vs 0.72 +/- 0.09% in CON at the base, P less than 0.01; and 0.55 +/- 0.08% in KD vs 0.30 +/- 0.05% in CON at the tip, P less than 0.01). However, fractional delivery of urea to the base and tip of the papillary collecting duct was not different between KD and CON rats (26.9 +/- 5.6% in KD vs 21.4 +/- 3.3% in CON at the base, P greater than 0.05; and 12.4 +/- 1.5% in KD vs 10.4 +/- 1.4% in CON at the tip, P greater than 0.05). Furthermore, reabsorption of water or urea between the base and tip of the papillary collecting duct was not decreased in KD as compared to CON rats (water reabsorption was 57.8 +/- 4.4% in KD and 55.9 +/- 5.11% in CON and urea reabsorption was 45.0 +/- 6.5% in KD and 45.9 +/- 5.4% in CON, P greater than 0.05). These results demonstrate that water reabsorption, but not urea reabsorption, is impaired in renal tubules proximal to the accessible papillary collecting duct in hydropenic rats.
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PMID:Urea reabsorption along the papillary collecting duct in potassium-deficient rats. 399 1


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