Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0035078 (renal failure)
 31,970 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The present paper describes the use of a quantitative renal vascular casting method to study the changes associated with kidney disease. Several animal models of hypertension (spontaneously hypertensive rat, SHR, with its normotensive rat the Wistar Kyoto, WKY; Dahl salt sensitive DS - hypertensive, and salt resistant DR - normotensive) were examined at time points when the systemic blood pressure was rising (6 and 12 weeks of age) and following renal denervation (in SHR-WKY rats). The SHR appears to have a smaller caliber afferent arteriole at both 6 and 12 weeks of age. This difference is probably not entirely due to sympathetic vasoconstriction since the strain related afferent arteriolar diameter difference was still present after renal denervation. In the Dahl rats, there is not much of an intrarenal vascular difference between the DS and DR rats with the only real finding of a smaller distal afferent arteriolar diameter found in outer cortical nephrons of the DR. The two models of acute renal failure (ARF) that were studied include, the glycerol model (known to initially cause an intense vasoconstriction) and gentamicin, a nephrotoxic antibiotic. Two time points were examined for each of these models. As expected in the glycerol model there was an intense vasoconstriction at three hours which essentially was gone at 3 days - a time when the renal failure was fulminant. The glomerulus appeared to be contracted at three hours as well. In the gentamicin model no renal vascular alteration was seen at 6 days, when renal failure was mild while at 10 days, when renal failure was pronounced, outer cortical afferent arterioles appeared to be moderately constricted. In the 5/6 nephrectomy model of chronic renal failure, the glomeruli were smaller in rats in renal failure than in the controls.
 ...
PMID:Quantitative renal vascular casting in nephrology research. 373 22

Kidney cortical and medullary "spin-lattice" (T1) and "spin-spin" (T2) relaxation times were measured by spectroscopy in several types of experimental renal failure in rats. The T1 and the measured tissue water content were used to calculate the fraction bound (FB) and hydration fraction (HF) according to a fast proton diffusion model. The present study demonstrated the possibility to differentiate between normal and pathological renal tissue resulting from renal artery clamping (RAC), renal pedicle clamping (RPC) with or without reflow, glycerol-induced acute renal failure with or without previous dehydration, and chronic hypertensive renal failure induced by 5/6 nephrectomy and saline loading, with low (6%) or normal (21%) protein diet. Shortened T1 and prolonged T2 found in both cortex and medulla of the glycerol-induced ARF in dehydrated rats seem to represent a MR ischemic pattern. The prolongation of T1 and T2 and the increase in water content in the other groups seem to relate to different amounts of tubular obstruction and renal congestion. In summary, characteristic MR properties of different types of renal failure may provide etiological and pathogenetic diagnostic possibilities.
 ...
PMID:Proton magnetic resonance in experimental acute and chronic renal failure in rats. 382 4

The present study was designed to evaluate the effect of acute fall in plasma osmolality in three models of acute tubular necrosis in rats: (a) glycerol, (b) arterial clamping and (c) mercuric chloride. Plasma osmolality was reduced by a water loading during a mild anaesthesia from 305 +/- 7 to 270 +/- 12 mosmol/kg of water (P less than 0.01). In the ischaemic models of acute tubular necrosis (glycerol and arterial clamping), during the first 24 h in rats with reduced plasma osmolality, the respective creatinine clearance rates (CCR), 0.04 +/- 0.02 and 0.06 +/- 0.04 ml/min, were strikingly lower than those in rats with normal osmolality, 0.21 +/- 0.03 and 0.26 +/- 0.06 ml/min (P less than 0.001) respectively. The control CCR were 0.65 +/- 0.07 and 0.62 +/- 0.07 ml/min respectively. During the second day after induction of ischaemic (glycerol and arterial clamping) acute tubular necrosis, rats with reduced plasma osmolality exhibited a similar worsening in CCR as on the first day, when compared with that in rats with normal osmolality. In rats with acute tubular necrosis induced with mercuric chloride reduction in plasma osmolality did not aggravate the severity of renal failure. These results show that acute fall in plasma osmolality worsens the renal failure in the ischaemic but not in the nephrotoxic models of acute tubular necrosis.
 ...
PMID:The effect of acutely reduced plasma osmolality on acute renal failure in rats. 388 36

To evaluate the effects of pharmacologic vasodilatation on glycerol-induced acute renal failure, we studied untreated animals and those given Captopril and Diltiazem at periods ranging from 30 minutes to four weeks after the onset of acute renal failure. At each time frame, comparative coded assessments of renal function, histology, and microangiography were performed. Diltiazem, a calcium channel blocker, significantly reduced the severity of the renal failure, decreased the extent of tubular cell necrosis, and was associated with a more rapid histologic and functional recovery. Captopril, an angiotensin converting enzyme inhibitor, did not influence renal function or pathology throughout the four-week observation period. Microangiography revealed marked differences among the experimental groups. Most notably, there was better visualization of the microvasculature in Diltiazem-treated kidneys at one and two weeks. However, at four weeks, all groups showed similar, severe microangiographic abnormalities. Diltiazem offers significant protection against glycerol-induced acute renal failure in rats. Its mechanism of action in this context remains unknown. Renal function and pathology do not correlate well with microangiographic perfusion patterns in this model of acute renal failure.
 ...
PMID:The effects of diltiazem and captopril on glycerol-induced acute renal failure in the rat. Functional, pathologic, and microangiographic studies. 390 88

Different nephrological derangements are observed in severe alcoholics. Until now the direct toxicity of ethanol is only shown in the fetal alcohol syndrome with various malformations of the genitourinary tract. In the adult the kidney is often involved in the development, maintenance and counterregulation of complex electrolyte disturbances like phosphate and potassium hypoglycemia etc. The alcohol associated retention of urate, induced by hyperlactatemia and/or increased beta-hydroxybutyrate concentration is only rarely complicated by urate nephropathy. Alcohol intoxication (acute and chronic) predisposes to rhabdomyolysis with the risk of acute renal failure. There are some hints that chronic alcoholism with myopathy increases the vulnerability of the kidney for further toxic agents. In rats glycerol induced renal failure is enhanced by alcohol pretreatment. Finally, regular alcohol consumption raises the blood pressure, which per se is a risk factor for renal damage.
 ...
PMID:Role of alcohol in clinical nephrology. 405 21

To assess the effects of altered renal function on Na-K-ATPase, the following groups of rats were studied: 1. rats with suprarenal vena cava ligation (SVCL), la. DOCA-treated rats with SVCL, 2. rats with infrarenal vena cava ligation (IVCL), 3. rats with glycerol-induced acute renal failure, 4. rats with bilateral ureteric ligation, and 5. K-exalate-treated rats with SVCL. In group 1, acute renal failure with hyperkalemia developed and medullary Na-K-ATPase increased from 95 +/- 5 in control to 155 +/- 7 mumol Pi/mg prot/h, P less than 0.001, DOCA did not prevent the increase of Na-K-ATPase. In group 2, medullary Na-K-ATPase decreased from 130 +/- 10 in control to 88 +/- 7, P less than 0.01, in rats with IVCL. In group 3, cortical Na-K-ATPase decreased from 55 +/- 5 to 27 +/- 6, P less than 0.02. In group 4, Na-K-ATPase was unchanged. In group 5, maintenance of normokalemia prevented the rise in Na-K-ATPase. These experiments demonstrated a K-dependent activation of medullary Na-K-ATPase after SVCL but not in other forms of renal failure. Because SVCL diminishes drastically GFR per nephron, the present findings imply that increased loads of Na and K per nephron are not a prerequisite for an increase in medullary Na-K-ATPase. Hyperkalemia in presence of increased renal venous pressure seems to be causally related to the rise in medullary Na-K-ATPase activity.
 ...
PMID:Renal function and Na-K-ATPase in rats after suprarenal ligation of inferior vena cava. 612 57

Acute renal failure induced by glycerol results in increased metabolism of glutamine by renal cortical slices of rats 16 and 36 hr after onset, and there is also increased glutamine uptake by the kidney in vivo. Metabolism of glutamine and glutamate to glucose is inhibited. At 8 days after onset of renal failure, metabolism of glutamine returns to normal. Initially, activities of phosphate-dependent glutaminase (PDG) and glutamate dehydrogenase are depressed. The activity of glutaminase returns to normal by 8 days, but glutamate dehydrogenase activity is still inhibited. Increased ammoniagenesis and glutamine uptake are mainly a result of increased entry into the cell since activity of glutaminase is inhibited.
 ...
PMID:Renal metabolism of glutamine in rats with acute renal failure. 613 Nov 57

To assess whether the secretory clearance of N1-methylnicotinamide (NMN), an endogenous organic cation, represents renal tubular secretion of the organic cation, the relationship between the secretory clearance of NMN, CLscn(NMN), and that of tetraethylammonium bromide (TEA), CLscn(TEA), was examined in normal and experimental renal failure (ERF) rats. TEA was selected as a representative organic cation secreted by the kidney. ERF was induced by glycerol, folate, salicylate, uranium, and gentamicin, substances which have been demonstrated to produce specific damage to the kidney by pathophysiological studies. Glomerular filtration rate (GFR), CLscn(NMN), and CLscn(TEA) decreased significantly in most of ERF rats, while blood urea nitrogen (BUN) increased significantly in all ERF rats. There was a statistically significant correlation (r = 0.952, p less than 0.001) between the endogenous CLscn(NMN) and CLscn(TEA) in both the normal and ERF rats. Correlation analysis revealed that CLscn(NMN) was superior to GFR in the degree of relationship to CLscn(TEA), but BUN could not be used as an index for the secretion of NMN or TEA. Although the plasma concentration of NMN in most of the ERF rats was much higher than that in the normal rats, it affected neither the urinary clearance of NMN itself nor the excretion of TEA. From these findings, we propose that CLscn(NMN) can be used as an index to assess renal tubular function for the secretion of organic cations that are excreted by both filtration and secretion without reabsorption.
 ...
PMID:Estimation of renal secretory function for organic cations by endogenous N1-methylnicotinamide in rats with experimental renal failure. 623 62

gamma-Glutamyl L-dopa, a renal pro-drug for dopamine, was administered to rats before and after injection of glycerol, and to a control group which received water in place of glycerol. A third group of rats was given glycerol but no gamma-glutamyl L-dopa. The plasma creatinine in rats given gamma-glutamyl L-dopa and glycerol was significantly lower than in rats receiving glycerol alone. The fall in urine creatinine excretion, and polyuria, after glycerol was reduced by gamma-glutamyl L-dopa and the natriuresis abolished. gamma-Glutamyl L-dopa given alone caused a 4000-fold increase in urine dopamine excretion, associated with a natriuresis. The administration of gamma-glutamyl L-dopa reduces the severity of renal failure produced by glycerol.
 ...
PMID:The protective effect of gamma-glutamyl L-dopa on the glycerol treated rat model of acute renal failure. 640 99

A new test for the laboratory diagnosis of spherocytosis, conventionally called 'Pink test', is presented. This test, semi-quantitatively or quantitatively, determines the hemolysis of small blood samples in a solution containing glycerol (135 mmol/l), NaCl (25 mmol/l), NaN3 (1.5 mmol/l), buffered to pH 6.66 with Bis-Tris (70 mmol/l) and HCl. 'Pink test', as well as 'acidified' glycerol lysis test, were positive in 100% of 42 patients suffering from hereditary spherocytosis, and optimally discriminated them from healthy subjects, showing a diagnostic sensitivity greater than 'standard' glycerol lysis test and osmotic fragility in hypotonic saline solutions of fresh or incubated blood. 'Pink test' was also positive in some cases of renal failure, immunohemolytic anemia, chronic hemoproliferative disorders, normal pregnant women, and negative in other microcytic anemias (beta-thalassemia, iron deficiency anemia). The results do not critically depend on pH of the solution (differently from those obtained with 'acidified' glycerol lysis test), and for this reason they show a good reproducibility.
 ...
PMID:A new test for the laboratory diagnosis of spherocytosis. 643 93


<< Previous 1 2 3 4 5 6 7 8 9 Next >>