Obstructive nephropathy: an update of the experimental research (original) (raw)
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Biochemical-molecular markers in unilateral ureteral obstruction
Biocell : official journal of the Sociedades Latinoamericanas de Microscopía Electronica ... et. al, 2007
Congenital obstructive nephropathy is the primary cause of end-stage renal disease in children. Rapid diagnosis and initiation of the treatment are vital to preserve function and/or to slow down renal injury. Obstructive uropathy effects -decline in the plasmatic renal flow and glomerular filtration rate, interstitial infiltrate of leukocytes, significant decrease of the urine concentration, loss of the capacity to concentrate urine as well as fibrosis and apoptosis- are a consequence of a variety of factors that work in complex ways and are still not fully understood. Mediators as angiotensin II, transforming growth factor-beta (TGF-beta) and nitric oxide (NO) have been implicated in congenital obstructive nephropathy. The renin-angiotensin system is regulated in different ways, affecting both renal structure and function, and that it in turn depends upon the duration of the obstruction. On the other hand, the role of nitric oxide in renal injury remains somewhat controversial due ...
Reversibility of glomerular filtration rate after surgery for unilateral obstructive Uropathy
Journal of Analytical Research in Clinical Medicine, 2015
Obstructive uropathy refers to the condition of obstruction of urine flow from the kidney to the bladder, which might be acute or chronic, complete or partial, and unilateral or bilateral. 1,2 The adverse effects of urinary-tract obstruction (UTO) on renal function have been investigated in several animal and human studies. 3-7 Severity, duration of obstruction, and being unilateral or bilateral are obvious imperative effective factors which may disturb the function of
The Egyptian Journal of Hospital Medicine, 2020
Background: Obstructive uropathy refers to any blockage of urine drainage at any level of the urinary tract. It may be chronic or acute and may occur unilateral or bilateral. The prediction of the recoverability of kidney function after treatment of unilateral obstructive uropathy is of great clinical value to the urologists and nephrologists as it may affect the decision of treatment. Objectives: To detect changes in split renal function of unilaterally obstructed kidney after a period of 6 weeks of drainage. Patients and methods: This prospective observational study included 66 adult patients divided into 2 groups; Group A included patients with split function less than 10 % (36 patients) and Group B included patients with split function of 10 % or more (30 patients). Results: The study showed that there were an insignificant difference between the two groups in age, sex, cause of obstruction, laterality of obstruction, method of drainage and patient's presentation. Also, there was an insignificant difference between pre-and post-drainage for group A (P-value 0.142). While there was a highly significance difference between pre-and post-drainage for group B (P-value < 0.001). Conclusion: the preoperative split function of the obstructed kidney is the independent factor affecting the recoverability of renal function. Where kidneys with split function less than 10% are irreversibly damaged and the decision of treatment can be taken with no need to do drainage followed by repeating renal scan. While stabilization or improvement of renal function is expected after relief of obstruction in kidneys with split function of 10% or greater.
Partial unilateral ureteral obstruction in rats
Neurourology and Urodynamics, 2002
This review comprises an overview of the current knowledge on experimental partial unilateral ureteral obstruction (PUUO) and a summary of our latest original experimental PUUO studies in rats. Neonatal PUUO is the type of obstruction that is most often encountered in pediatric clinical practice. However, the pathogenesis of PUUO is still incompletely understood. Most of our knowledge on PUUO has been derived from experimental studies in a variety of animal models. Although progress has been made, the natural history of congenital hydronephrosis is still incompletely described. The e¡ects on kidney functions of long-term urinary tract obstruction, especially PUUO, have been less intensively studied. Recently, we created models with mild and severe PUUO in young rats by embedding the upper one fourth or the upper two thirds of the left ureter into the psoas muscle, respectively. Thereafter, the technique was used to create mild and severe PUUO in newborn rats and magnetic resonance imaging studies showed that both mild and severe obstruction caused a time-dependent decrease in renal blood £ow. Compensatory increase in total kidney volume and renal vein blood £ow in contralateral non-obstructed kidneys was not detectable when functional deterioration in the partially obstructed kidneys was present. Finally, we investigated the dynamic changes in renal relative signal intensity (RSI) of gadolinium-diethylenetriamine pentaacetic acid (Gd-DTPA) using magnetic resonance imaging in rats with partial, complete unilateral ureteral obstruction and sham-operated controls. The results showed that changes in Gd-DTPA RSI are compatible with the known physiological and anatomical changes in kidneys in response to ureteral obstruction and useful for distinguishing an obstructed from a non-obstructed collecting system and also for di¡erentiating a partially obstructed from a completely obstructed collecting system.
American Journal of Physiology-Renal Physiology
Following the release of short periods of unilateral ureteral obstruction (UUO), glomerular filtration rate (GFR) recovers by time. However, research in experimental animal models has demonstrated the presence of an ongoing element of renal interstitial fibrosis a few weeks following UUO reversal. Interstitial fibrosis can cause deterioration in GFR, and it is not known whether it leads to an ongoing slow deterioration in other renal functions despite the apparent initial recovery postreversal. To investigate this, rats underwent a 72-h reversible UUO. Renal functions of nonobstructed and previously obstructed kidneys were measured 1, 4, and 18 mo postreversal. GFR in nonobstructed and previously obstructed kidneys was similar up to 18 mo postreversal. However, there was ongoing tubulointerstitial fibrosis, and the degree of tubular atrophy and dilatation deteriorated by time. This was associated with an increase in urinary albumin leakage and alterations in renal injury markers, pr...
Obstructive nephropathy is the functional and /or parenchymal renal damage secondary to the urinary tract occlusion at any part of it. The inducing urinary obstruction diseases can vary depending on the patient´s age and gender.
Early release of neonatal ureteral obstruction preserves renal function
American Journal of Physiology-Renal Physiology, 2004
The incidence of congenital hydronephrosis is ∼1% and is often associated with renal insufficiency. It is unknown whether early release is essential to prevent deterioration of renal function. Rats were subjected to partial unilateral ureteral obstruction (PUUO) on postnatal day 2. The obstruction was left in place or released after 1 or 4 wk. Renal blood flow (RBF) and kidney size were measured sequentially over 24 wk using MRI. In rats in which the obstruction was left in place, RBF of the obstructed kidney was progressively reduced to 0.92 ± 0.17 vs. 1.79 ± 0.12 ml·min−1·100 g body wt−1( P < 0.05) after 24 wk. Similarly, glomerular filtration rate of the obstructed kidney was severely reduced at 24 wk: 172 ± 36 vs. 306 ± 42 μl·min−1·100 g body wt−1( P < 0.05). These changes were preceded by development of severe hydronephrosis and obstructive nephropathy with a reduction in total protein content: 45 ± 3 vs. 58 ± 4 mg/kidney. Moreover, nonreleased PUUO caused a marked natriu...
Impact of age on effects of ureteral obstruction on renal function
Kidney International, 1983
Chronic partial ureteral obstruction of the urinary tract is a common congenital abnormality. Yet, its impact on the function of the kidney in the young has not been examined. To determine the relationship between age at the time of injury and outcome, partial ureteral obstruction was produced in guinea pigs during the first, second, third, fourth, or fifth week of life, and several variables of glomerular, proximal and distal tubular functions were measured 4 weeks later. The results were compared with those obtained in the contralateral kidney and with those observed in age-matched sham-operated animals. There was a significant impairment in the growth of the obstructed kidney. The weight of the contralateral kidney in the experimental animals was significantly greater than that of the obstructed (P less than 0.001) or control (P less than 0.005) kidney, but compensatory hypertrophy decreased progressively with age, being 30% of control when the obstruction was produced in the second week of life and only 2% when the obstruction occurred at 5 weeks of age. Obstruction resulted in a marked reduction in GFR at all ages, the impairment being inversely proportional with age. Conversely, the increase in GFR on the contralateral side, which was proportional with the increase in renal mass, diminished from 60.1 to 20.5% (r = 0.96, P less than 0.001) as a function age. Tubular reabsorption of phosphate was significantly lower in obstructed kidneys, particularly so in the animals sustaining obstruction during the first 2 weeks of life.(ABSTRACT TRUNCATED AT 250 WORDS)
Kidney International, 2008
Experimental unilateral ureteral obstruction (UUO) is widely used to study renal fibrosis; however, renal injury can only be scored semiobjectively by histology. We sought to improve the UUO model by reimplanting the obstructed ureter followed by removal of the contralateral kidney, thus allowing longitudinal measurements of renal function. Mice underwent UUO for different lengths of time before ureteral reimplantation and contralateral nephrectomy. Measurement of blood urea nitrogen (BUN) allows objective evaluation of residual renal function. Seven weeks after reimplantation and contralateral nephrectomy, mean BUN levels were increased with longer duration of UUO. Interstitial expansion, fibrosis, and T-cell and macrophage infiltration were similar in kidneys harvested after 10 days of UUO or following 10 weeks of ureter reimplantation, suggesting that the inflammatory process persisted despite relief of obstruction. Urinary protein excretion after reimplantation was significantly increased compared to control animals. Our study shows that functional assessment of the formerly obstructed kidney can be made after reimplantation and may provide a useful model to test therapeutic strategies for reversing renal fibrosis and preserving or restoring renal function.