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

The role of renal tubules was explored by two kinds of experiments: (1) inhibition of the tubular reabsorption of insulin by induced polyuria; (2) suppression of insulin filtration by ureter clamping; 1. Anaesthetized dogs maintained in normoglycaemia by glucose compensation were infused with crystalline and 125I-insulins. Polyuria was induced by: (1) saline-bicarbonate infusion; (2) furosemide with saline-bicarbonate infusion to replace urine losses; (3) massive infusion of mannitol. Inulin and paraminohippuric acid were used to estimate the glomerular filtration rate and the renal plasma flow. The permeability of the glomerular wall (pore radius and total area of the pores per unit of path length) was determined by measuring the sieving curve of 131I-polyvinyl-pyrrolidone fractions during basal and treatment periods. Mannitol infusion was able to bring the insulin/inulin clearance ratio up the values of the sieving coefficient of insulin (insulin filtration rate) without modifying the permeability of the glomerular wall; saline infusion displayed a similar effect; furosemide, only a minute one although it induced a more marked polyuria. 2. Clamping of the left ureter was performed on dogs with catheters inserted into the artery, the left renal vein, the pelvis and a renal lymphatic vessel. Almost complete suppression of the glomerular filtration was achieved. It slightly increased the high insulinic concentration of the renal lymph, entailed a 1/3 decrease in the extraction ratio of insulin and reduced by half its renal clearance. In conclusion, the tubules participate to the catabolism of insulin by two different mechanisms: (1) an uptake from the tubular fluid which can be inhibited by diuretics exerting their main action on the proximal tubules; (2) a direct catabolism from the interstitial fluid resulting from the large permeability of the peritubular capillaries to insulin.
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PMID:The participation of the renal tubules to the metabolism of insulin. 100 Oct 4

Rats with mammillary electrolytic lesions show a strong polydipsia and polyuria. This over-consumption may be primary or secondary to the polyuric effect. In this regard, mammillary lesioned rats excrete a greater amount of urine compared with control animals when matched in daily water consumption (partial water deprivation). Moreover, this abnormal water intake is significantly reversed by treatment with Pitressin, a vasopressin analogue. These results suggest that the polydipsia may be determined by the urinary water loss. However, when subjected to the bilateral ureter ligation, the experimental animals still outdrink the control ones, thus also suggesting a primary component of the polydipsia under study. The possible explanation of these components in relation to the mammillary polydipsia is discussed.
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PMID:[Primary/secondary characteristics of polydipsia induced by electrolytic lesion of the mammillary bodies]. 250 36

Nephrogenic diabetes insipidus usually presents with polyuria, polydipsia, fever, vomiting, dehydration and failure to thrive. However, in infancy polyuria may be absent because of dehydration and reduced glomerular filtration rate. In 2 cases the main presenting feature was hypotonia, with marked head lag. Family studies confirmed the X-linked mode of inheritance of the disease; in case 1 the disease appeared to have arisen as a new mutation in the mother, and in case 2 the carrier status was traced back to the great-grandmother. Pitfalls in the diagnosis and detection of the carriers are discussed. Treatment with thiazide diuretics and prostaglandin synthesis inhibitors is effective in reducing urine volumes and polydipsia. The early detection of the disease and adequate management may prevent such complications as megacystis, mega-ureter and hydronephrosis, with resulting renal failure. Mental and physical retardation may also be avoided.
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PMID:Nephrogenic diabetes insipidus presenting with infantile hypotonia. A report of 2 cases. 373 62

Electromyogram (EMG) and bolus volume of ureteral peristalsis were measured during gradual and rapid urinary flow increase in mongrel dogs. In acute diuresis induced by furosemide, the ureteral peristaltic rate rose and then the bolus volume increased with a consequent increase of urine flow. During a course of gradually increasing urine secretion, the ureter showed varying responses in respect to peristaltic rate (i.e., increase, no change and decrease) but changes in the bolus volume consistently made up for the rate alterations, thereby eventually maintaining an efficient equilibrium of these two urodynamic parameters to effect an increase in urine flow. The ureteral peristaltic rate increases only several times in polyuria as compared to the rate in oliguria, whereas the bolus volume of urine increases by a factor of 100. This indicates that it is not so much the ureteral peristaltic rate as the bolus volume which plays a principal part in the transport of urine through the ureter.
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PMID:The role of ureteral peristaltic rate and bolus volume on increasing urine flow. 375 May 77

Escherichia coli-induced pyelonephritis was studied in untreated alloxan-diabetic rats, insulin-treated diabetic rats, glucose water-drinking (diuresing) nondiabetic rats, and tap water-drinking (nondiuresing) nondiabetic rats following injection of E. coli either into the emptied urinary bladder, into the left kidney, or intravenously. For prevention of an ascending infection in the right kidney, the right ureter was ligated and transected immediately prior to bladder or intrarenal inoculation. These experiments established that in normal rats ascending renal infection alone occurred following introduction of small inocula into the bladder--and then only when facilitated by diuresis. In diabetic rats both ascending and hematogenous renal infection occurred following introduction of small inocula into the bladder. Insulin treatment that reduced hyperglycemia also reduced glycosuria and restored urinary antibacterial activity against small inocula of E. coli but only partially reduced polyuria and prevented hematogenous but not ascending infection. Thus, hyperglycemia was probably the major factor promoting hematogenous renal infection, whereas polyuria--and therefore vesicoureteral reflux--was the major factor promoting ascending infection.
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PMID:Effect of insulin treatment on the susceptibility of the diabetic rat to Escherichia coli-induced pyelonephritis. 638 97

Comparative analysis of two types of ureterocystic anastomosis in kidney transplantation showed the advantages and shortcomings of the method developed at the Moscow Regional Scientific Research Clinical Institute. The new anastomosis fundamentally differs from the traditional Mebel-Shumakov method in the absence of sutures between the ureter and the bladder mucosa. This feature makes it possible to avoid injury to the bladder mucosa which is often changed in prolonged anuria and reduce the edema and ischemia of the terminal part of the ureteral graft. This facilitates adaptation of the anastomosis to polyuria which often occurs in the early postoperative period. The relatively simple techniques shortens the time needed for the operation. These advantages of the new method of ureterocystotomy are manifested by decrease of the total number of urological complications and the relative incidence of serious early urological complications like fistula of the ureterocystic anastomosis and necrosis of the ureter which most often lead to loss of the transplant and sometimes to death of the patient. The use of the anastomosis developed at the Clinical Institute, however, is attended by a relatively high incidence of ureteral stricture in the late-term postoperative period, evidently due to prolonged contact of urine with the bladder muscular coat and the ureteral adventitia. Thus, the more favorable results of ureterocystic anastomosis formed by the method developed at the Clinical Institute allow it to be recommended for further use in kidney transplantation.
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PMID:[Comparative evaluation of two methods for the uretero-cystic anastomosis]. 796 93

The influence of increased functional load on the macroscopical and histological appearance of the ureter was investigated. Sixty rats were divided into five groups: (1) sucrose-fed rats with non-osmotic polyuria; (2) diabetic rats with osmotic polyuria; (3) uninephrectomized rats; (4) sham-operated control rats; and (5) control rats. The 24-hour urinary volume was measured on days 7, 14 and 21. Growth of the kidney, ureter and bladder was investigated and the histological appearance of the ureter was further evaluated. Diabetic and sucrose-fed rats had comparable polyuria with a seven-fold increase in urinary output. The urinary volume for the remaining kidney was doubled in uninephrectomized rats. After 3 weeks, diabetic rats had increased weight of the kidney, ureter and bladder, sucrose-fed rats had increased weight of the bladder, whereas uninephrectomized rats had increased weight of the kidney and ureter. The cross-sectional area (CSA) of the ureter wall from control rats increased from the proximal to the distal portion. The size of the whole ureter from diabetic rats was dramatically increased, the CSA of the wall of the distal ureter portion being four times that of the controls. The CSA of the ureter wall from sucrose-fed rats was increased only in the distal portion, whereas the ureter from uninephrectomized rats was increased only in the proximal portion. The results demonstrate the importance of differentiating between different portions of the rat ureter when examining histological sections of this organ. Moreover, polyuria per se is shown to induce growth of the bladder and of the adjacent distal part of the ureter, whereas uninephrectomy and diabetes caused growth of the kidney and the upper parts of the ureter, in addition to the growth induced by polyuria.
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PMID:Ureteral growth in animal models with increased renal excretion of urine. 1009 52

A 2-year-old quarter horse gelding presented for evaluation of polyuria and polydipsia. Azotemia was detected on serum chemistry profile. Small, misshapen, hyperechoic kidneys with decreased corticomedullary demarcation, hydronephrosis, and a right nephrolith were noted ultrasonographically. The diagnosis of end-stage kidney disease and dysplasia was made histopathologically using ultrasound-guided biopsy. Two ureteroliths were found in the right ureter via cystoscopy, and a nephrolith was seen in the right kidney at necropsy. Clinical, ultrasonographic, and pathologic features of equine urolithiasis and renal dysplasia are discussed.
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PMID:Chronic renal failure associated with nephrolithiasis, ureterolithiasis, and renal dysplasia in a 2-year-old quarter horse gelding. 1046 29

A 68-year-old man with a history of nephrectomy of the right kidney was admitted to our hospital with a 1-month history of polyuria (> 41 per day). He also exhibited hyposthenuria, which was unresponsive to treatment with exogenous vasopressin. Radiographic examination revealed partial obstruction of the left ureter and moderate hydronephrosis. The cause of the obstruction was cancer of the ureter. After drainage using a nephrostomy tube, the polyuria and hyposthenuria were gradually resolved. This is the first known case of nephrogenic diabetes insipidus due to hydronephrosis in a patient with a solitary kidney.
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PMID:Nephrogenic diabetes insipidus due to hydronephrosis in a patient with a solitary kidney. 1458 22

The renin-angiotensin system is well known to be involved in the pathophysiological changes in renal function after obstruction of the ureter. Previously, we demonstrated that bilateral ureteral obstruction (BUO) is associated with dramatic changes in the expression of both renal sodium transporters and aquaporin water channels (AQPs). We now examined the effects of the AT(1)-receptor antagonist candesartan on the dysregulation of AQPs and key renal sodium transporters in rats subjected to 24-h BUO and followed 2 days after release of BUO (BUO-2R). Consistent with previous observations, BUO-2R resulted in a significantly decreased expression of AQP1, -2, and -3 compared with control rats. Concomitantly, the rats developed polyuria and reduced urine osmolality. Moreover, expression of the type 2 Na-phosphate cotransporter (NaPi-2) and type 1 bumetanide-sensitive Na-K-2Cl cotransporter (NKCC2) was markedly reduced, consistent with postobstructive natriuresis. Candesartan treatment from the onset of obstruction attenuated the reduction in GFR (3.1 +/- 0.4 vs. 1.7 +/- 0.3 ml.min(-1).kg(-1)) and partially prevented the reduction in the expression of AQP2 (66 +/- 21 vs. 13 +/- 2%, n = 7; P < 0.05), NaPi-2 (84 +/- 6 vs. 57 +/- 10%, n = 7; P < 0.05), and NKCC2 (89 +/- 12 vs. 46% +/- 11, n = 7; P < 0.05). Consistent with this, candesartan treatment attenuated the increase in urine output (58 +/- 4 vs. 97 +/- 5 microl.min(-1).kg(-1), n = 7; P < 0.01) and the reduction in sodium reabsorption (433 +/- 62 vs. 233 +/- 45 micromol.min(-1).kg(-1), n = 7; P < 0.05) normally found in rats subjected to BUO. Moreover, candesartan treatment attenuated induction of cyclooxygenase 2 (COX-2) expression in the inner medulla, suggesting that COX-2 induction in response to obstruction is regulated by ANG II. In conclusion, candesartan prevents dysregulation of AQP2, sodium transporters, and development of polyuria seen in BUO. This strongly supports the view that candesartan protects kidney function in response to urinary tract obstruction.
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PMID:Angiotensin II mediates downregulation of aquaporin water channels and key renal sodium transporters in response to urinary tract obstruction. 1675 30


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