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

Uninephrectomized ewes were prepared with a renal artery flow probe and catheters were implanted into the renal artery, vein, and ureter. The renal perfusion pressure (RPP) of conscious animals was decreased externally by 13 +/- 3, 21 +/- 3, 31 +/- 3 mmHg over 5 min and returned to control levels over 5 min. Reduction of RPP by 13 and 21 mmHg resulted in prompt increases in renin secretion (RS) which were maximal coincident with the nadir of the downward ramp (delta RS 195 +/- 43 P less than 0.05, and 1,077 +/- 208 ng AI/min, P less than 0.01, respectively). Directly measured renal blood flow (RBF) was not decreased and no measurable change occured in GFR. When RPP was reduced by 31 mmHg, RBF and GFR were decreased and renin secretion rose further (delta RS 1,480 +/- 384 AI/min, P less than 0.05). On the upward pressure ramp, RS fell promptly and was nearly at control levels upon restoration of RPP. It was concluded that renin secretion responds rapidly to alterations in RPP in the autoregulatory range and these changes in renin secretion are unlikely to be mediated by a tubular receptor.
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PMID:Renin secretion during dynamic changes in renal perfusion pressure. 44 36

There is one renal disease in which unilateral estimation of GFR is desirable for clinical purposes: chronic pyelonephritis. Considering the possibilities for complications to determine unilateral renal function by ureter catheter just in this group of patients, we tried to estimate unilateral GFR with 66mTc-DTPA after a single injection of 5 mCi i.v. on the basis of blood samples at 90, 110 and 130 min after injection and evaluation of gamma-camera data from 25 to 35 min after administration of the dose. 31 patients were studied. In arenal patients clearance values were 7.5 ml/min (+/- 10.47 ml/min), unilaterally nephrectomized patients showed zero values for the removed kidney. Normal patients had a mean GFR of 107 +/- 17.7 ml/min with a partition between right and left kidney of 54.2 +/- 10 to 52.75 +/- 8.5 ml/min. Patients without urinary tract obstruction and unilateral renal disease had values of 27.1 +/- 11 ml/min for the diseased kidney while the normal kidneys gave a mean value of 59.6 ml/min (+/- 13 ml/min). In the presence of urinary tract obstruction, data could not be correlated to the state of renal function. This shows that unilateral estimation of GFR using 99mTc-DTPA is basically possible, but that it is useless in obstructive kidney disease.
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PMID:Unilateral estimation of glomerular filtration rate with 99mTc-DTPA. 69 96

The reabsorption and excretion of sodium, chloride, potassium and water were investigated subsequent to loading with saline solution before and after unilateral hydronephrosis with partial obstruction to flow had been induced in 23 dogs by ligation of the ureter over an indwelling catheter. In the experimental kidney the increase in the total excretion of sodium and chloride and of water in per cent of GFR and the decrease in the reabsorption of sodium, chloride and potassium in per cent of the filtered loads were statistically significant. The glomerulotubular balance was altered statistically probably significantly, but the relation between the capacities for reabsorption of sodium and glucose was maintained. The renal pelvic dilatation was measured and plotted against the degree of renal functional impairment. A statistically significant inverse correlation was noted between renal pelvic volume and reabsorption of sodium and of chloride in per cent of the filtered loads. The osmolality of the urine was the parameter showing the most marked difference between the hydronephrotic and the contralateral kidney. For sodium and chloride the difference between the two sides in the reabsorbed amount in per cent of the filtered load was correlated probably significantly to the degree of renal pelvic dilatation.
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PMID:Renal function in experimental chronic hydronephrosis. IV. Renal handling of sodium and water. 99 53

Studies of renal function comprising determination of exogenous creatinine clearance, urinary osmolality and TmG were performed on 23 dogs, for each kidney separately, after hydronephrosis with partial ureteric obstruction had been produced by ligation of one ureter over an indwelling catheter. A method for determining the volume of the hydronephrotic renal pelvis was developed and the degree of functional reduction was correlated to the degree of pelvic dilatation. In 11 cases the renal blood flow was determined by direct measurement. Statistically significant reductions of the glomerular and tubular functions were noted on the hydronephrotic side. TmG and the urinary osmolality showed the greatest percentual decreases and the TmG/GFR ratio the smallest. The decrease in this ratio was due to greater deterioration of tubular than of glomerular function. The renal blood flow was reduced on the hydronephrotic side in comparison with the intact side, but seemed relatively less affected than the glomerular and tubular functions. Compensation by the intact kidney resulted in masking of the deterioration on the hydronephrotic side; thus for the whole material the mean GFR and urinary osmolality for the two kidneys together remained essentially unchanged. No statistically significant correlation between the degree of functional reduction and the degree of pelvic dilatation was found. Such a correlation could therefore not be used in the individual case as an indication of the functional capacity of a kidney.
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PMID:Renal function in experimental chronic hydronephrosis. III. Glomerular and tubular functions in relation to renal pelvic volume. 99 54

Phosphocreatine (PCr) is a critical intracellular energy reservoir used in the regeneration of ATP. The aim of this study was to determine the efficacy of exogenously added PCr on preservation of renal function in an in vitro model. The renal artery and ureter of a rat were cannulated and the kidney was subjected to 45 min of normothermic in vivo ischemia. The kidneys were then perfused ex vivo with either a Krebs-bicarbonate solution (Krebs) or a Krebs solution containing 3 mM PCr or an osmotically balanced solution containing 3 mM PCr. Our results indicate that the perfusion of kidneys subjected to 45 min of warm ischemia with solutions containing PCr resulted in significant improvements in GFR, RPF, and V, FRNa and FRH2O compared to KREBS alone. This suggests that the important factor in preservation of kidney function after an initial ischemic insult may be the addition of PCr rather that the electrolyte solution used.
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PMID:Amelioration of renal ischemic injury by phosphocreatine. 192 64

In ten patients, who underwent ESWL of renal calculi and had severe ureteral colic due to acute obturation of the ureteral lumen by larger stone fragments, i.v. glucagon injections combined with laevulose infusion were applied. All patients reported relief of pain and discomfort within 15-20 minutes after glucagon injection. Position of the stones in the ureter was regularly checked. No particular adverse effects of glucagon were noted. Glucagon increases GFR and diuresis and exhibits spasmolytic effect on the smooth muscle of the ureteral wall, thus facilitating the passage of stone fragments after ESWL. In certain cases and with certain indications we recommend the method as highly effective.
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PMID:A new method for the management of ureteral colic after extracorporeal shock wave lithotripsy. 340 92

A partial obstruction of the left ureter was created in six-week-old rats. The effects on renal function were studied after three, nine and 15 weeks, first in normal hydration, and then after extracellular volume expansion. Moderate hydronephrosis without parenchymal weight reduction developed within three weeks. The hydronephrotic kidney i) excreted during normal hydration less urine and sodium than the intact one, because of increased reabsorption, ii) was capable of reacting fully on volume expansion and iii) had, after volume expansion, a higher renal blood flow and GFR but also a higher reabsorption of water, sodium, potassium and osmoles, resulting in excretions similar to those on the intact side. The differences noted were small (less than 20%) except for sodium excretion. The hydronephrotic kidney seemed to tolerate an increase in ureteral resistance better than the intact one would do. There were no significant differences between the three, nine and 15-week groups, with regard to the effects on the hydronephrotic kidney. Thus, except for a tendency to sodium retention, the effects of partial ureteric obstruction in young rats seem to be relatively harmless and do not increase with time.
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PMID:Partial ureteric obstruction in the pubescent rat. I. Long-term effects on renal function. 359 70

Fifty-one children had unilateral ureteric reimplants for primary vesicoureteric reflux over an 11-year period. Reflux was abolished in 50 patients but in 8 (15.7%) it developed or became worse on the contralateral side. An isotope renal scan (99mTc DMSA) was carried out in 15 of the 18 patients who had grossly scarred or dysplastic kidneys. Thirteen of these had less than 22% of total function coming from the affected kidney and seven had less than 10% of their total GFR coming from the kidney whose ureter had previously been reimplanted. Five of these children have undergone nephrectomy and it is felt that this would have been a better initial procedure. No patient was hypertensive at the conclusion of the study.
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PMID:Unilateral ureteric reimplantation for primary vesicoureteric reflux in children. A policy re-evaluated. 402 10

A partial obstruction of 1 ureter was created in newborn rats and its effects were studied in the adult rat. The obstructed pelvis was found to be considerably enlarged. Nevertheless, the GFR (glomerular filtration rate) was only slightly decreased (10 per cent), completely compensated by increase on the contralateral, non-obstructed side. The reduction in GFR was less than the reduction in number of glomeruli (19 per cent), indicating a raised filtration rate per glomerulus. Water excretion was slightly increased and potassium excretion moderately decreased; sodium and osmolar excretion were not significantly affected. There was no correlation between these changes and the degree of pelvic enlargement. Thus, in this model, in which there is no urinary tract infection or pyelonephritis, partial obstructive uropathy caused less damage to the kidney function than might have been expected.
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PMID:Experimental obstructive hydronephrosis in newborn rats. III. Long-term effects on renal function. 683 22

The effect of different albumin concentrations on whole kidney function has been studied in the isolated perfused rat kidney. When a dialyzer was included in the perfusion circuit, GFR and sodium transport remained nearly constant for 2 h. Perfusion flow rate was directly correlated with albumin concentration. GFR was low (0.56 ml.min-1.g-1) at high albumin concentration (7.6 g/100 ml) and highest (1.38 ml.min-1.g-1) when albumin was omitted. The latter observation differed from earlier findings by other investigators who found a reduced GFR in the absence of albumin. This reduced GFR could be explained by ureteral backpressure, which results from the use of narrow ureter catheters. Fractional sodium reabsorption was approximately 50% irrespective of load when albumin was absent, and reached 90% at a GFR of 0.95 ml.min-1.g-1 when 5-6 g/100 ml albumin was used. At reduced load, fractional sodium reabsorption approached in vivo values of 98%. Potassium secretion was observed at high urinary flow rates when albumin concentration was low; low urinary flow rates at high protein concentration were associated with net potassium reabsorption.
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PMID:Effect of albumin on the function of perfused rat kidney. 724 41


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