UMLS:C0022116 - FACTA Search

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Query: UMLS:C0022116 (ischemia)
91,303 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Tubular function in the early phase (one to three hours) after transplantation of rat kidneys was analyzed with respect to glomerular filtration, vascular and tubular pressures, and excretory variables. Kidneys exposed to a short period of cold ischemia (two hours) functioned almost normally, except for a polyuria. After 12 and 16 hr of cold ischemia, nephron heterogeneity appeared with 1) "normal" tubules, 2) dilated tubules, and 3) collapsed tubules. In the "normal" tubules, the pressure was increased to 20 mm Hg, and the filtration was reduced in proportion to the mean net driving force. The dilated tubules had no filtration due to a more or less complete tubular obstruction, probably located in the thin loop of Henle and in the collecting ducts. The collapsed tubules had no filtration due to glomerular ischemia, which in turn might be the consequence of afferent arteriolar constriction. The total GFR was greatly reduced since only the "normal" tubules contributed to the total filtration. Concentrating ability and potassium secretion were also impaired. We interpreted this impairment as being due to medullary dysfunction, which would explain the isosthenuria and the impaired potassium transport.
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PMID:Nephron function of the transplanted rat kidney. 35 5

The present study was carried out to examine the effect of potassium depletion in rat kidneys subjected to a temporary ischemic event produced by clamping of left renal artery. The postischemic kidneys of rats on a normal diet with adequate potassium intake showed an increase in H2O, Na and K excretion, with no change in inulin clearance whereas significant differences were found in potassium-deprived rats. Potassium depletion was brought about by dietary K deprivation for 10 days. K-depleted rats (serum K = 2.5 +/- 0.1 mEq/l) had a decrease in inulin clearance of the postischemic kidney from 1.01 +/- 0.10 to 0.43 +/- 0.05 ml/min (p less than 0.01), and a greater increase in fractional excretion of H2O, Na and K when compared to normal rats. The postischemic kidney from both normal and hypokalemic rats showed a decrease in Na-K-ATPase of the inner stripe of the outer medulla. These data indicate that short-term ischemia produces polyuria, increases natriuresis and kaliuresis, associated, at least in part, with a decrease in Na-K-ATPase in the inner stripe of the outer medulla (probably the thick ascending limb of Henle) and that K depletion potentiates ischemic renal failure.
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PMID:Effect of potassium depletion on ischemic renal failure. 253 74

A 23-year-old male was admitted to hospital with severe dehydration and hypokalemic myopathy due to secondary aldosteronism. On admission serum sodium and chloride were markedly elevated to 198 mEq/l and 169 mEq/l, respectively, and serum potassium was down to 2.3 mEq/l. Serum electrolytes were normalized by transfusion therapy, but subsequently rhabdomyolysis grew worse due to metabolic abnormalities such as dehydration, hypothermia, oppressive ischemia and metabolic acidosis, at the same time transient polyuria and the elevation of serum myoglobin and enzymes originating in muscle tissue were observed. Serum CPK went up to 26,532 IU/l on the sixth day and other enzymes reached a peak following CPK. Dexamethasone was administered when the increase in enzyme levels caused the patient to fall into a stupor. He rapidly regained consciousness from the 15th day after admission, and he was able to stand up on the 29th day. Serum enzymes originating in muscle tissue decreased gradually to the normal range by the 30th day and no renal failure occurred.
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PMID:A case of severe dehydration with marked rhabdomyolysis. 402 Dec 12

Interaction of sulpiride - both 1- and d- isomers as well as racemic- - with Dopamine (DA, subpressor dosage 0.1 microgram X kg -1 X min -1), on the renal hemodynamic, was studied in DOCA-pretreated men during hypotonic polyuria. P.A.H. and creatinine clearance and renal vascular resistances were determined. In the presence of d-Sulpiride, DA - induced renal vasodilation is carried out gradually and finally reaches similar levels as in the absence of d-Sulpiride. However no glomerular filtration rate increase is produced by DA. In the presence of 1-Sulpiride, DA vasodilating effect is suppressed. On the contrary a trend toward ischemia and a reduction in glomerular filtration rate becomes finally apparent. Stronger binding of 1- than d-Sulpiride with vascular DA receptors in suggested. When both isomers are simultaneously administered (at the nearly total dosage) much less inhibitory effect on DA vasodilator action is observed: it seems that each isomer decreases the affinity on the other isomer for vascular DA receptors.
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PMID:[Sulpiride (stereoisomers, racemic) and dopamine: actions and interactions on renal circulation]. 670 43

Acute renal failure was induced in rats by clamping the renal artery for 45 min. After reestablishing renal blood flow, tubular heterogeneity was observed, with (1) seemingly normal tubules, (2) dilated tubules and (3) collapsed tubules. Micropuncture techniques were used to examine the hydrostatic pressures in the different nephrons and superficial vessels, and also to determine single nephron glomerular filtration rate. The dilated tubules showed minimal filtration, due to an elevated intratubular pressure probably caused by obstructions; in these nephrons filtration could be induced by lowering the intratubular pressure. In the "normal" nephrons there was some filtration, as the proximal tubular pressure was only moderately increased. No filtration took place in the collapsed type, probably as a result of glomerular ischemia and consequently decreased glomerular capillary pressure. The kidneys also exhibited isosthenuric polyuria with a reduced potassium secretion. It is suggested that a medullary ischemia will lead to interstitial and intracellular edema and eventually cell necrosis with subsequent formation of obstructions in the loops of Henle. The obstructions would explain the increase in proximal tubular pressure and the decrease in total kidney filtration to about 5% of the normal. It is proposed that the deficient urine concentration ability and the inhibited potassium secretion are caused by the ischemic damage to the renal medulla.
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PMID:Nephron function in postischemic acute renal failure. 712 68

Experimental work in our laboratory has confirmed the protective activity of vanadium compounds on hyperglycemia and glycosuria in streptozotocin (STZ) diabetes. Furthermore, diabetic cataract has also been partially prevented. Nevertheless, the combination of a natural antioxidant, vitamin E, with Na3 VO4 has not further enhanced this ameliorating effect. Our experimental approach has been an attempt to block the prooxidant activity of both STZ and vanadate, with the purpose of eliciting the best possible antidiabetic protection. More recently, a lipid soluble synthetic antioxidant U-78517F, a 2-methylaminochroman, has been reported to have a significant protective effect against brain injury and ischemia. This compound inhibits the iron-dependent lipid peroxidation 100 times more effectively than vitamin E. This investigation has introduced a combination of the vanadium compound plus the aforesaid lazaroid, as its (-) enantiomer, U-83836E, in order to improve the insufficient protection when vitamin E was used. For twelve weeks, male Wistar rats, rendered diabetic with STZ, were administered Na3VO4 in drinking water along with the lazaroid carried by the food. Four, eight and twelve weeks after the beginning of the protective treatment, fluid and food intake, diuresis and excreted feces, glycosuria and proteinuria were determined on biological samples obtained in metabolic cages; body weight and glycemia were also recorded. At weeks 6 and 12 of the treatment, the opaqueness of the eye lenses was controlled and registered. At the end of the experiment, circulating glycosylated hemoglobin (HbA1c), fructosamine, N-acetyl-beta-D-glucosaminidase (NAG), and fluorescent peroxides were evaluated. Within the first month of treatment, protection by the combination paralleled that elicited by vanadate alone. At subsequent steps, U-83836E significantly improved the protective effect of vanadate alone on polydipsia and polyuria, but especially on hyperglycemia and glycosuria. The further ameliorating effect of the lazaroid was also observed on HbA1c and NAG, and, most important, on the cataract. In conclusion, these findings demonstrate that the lazaroid U-83836E succeeds in further protecting the most important symptoms of diabetes treated with vanadate, and that this antioxidant acts effectively even when it is administered orally in food, in a non invasive manner.
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PMID:Amelioration of diabetes and cataract by Na3VO4 plus U-83836E in streptozotocin treated rats. 782 6

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

This study was carried out to determine the effect of renal ischaemia on transport systems for organic compounds in the rabbit kidney proximal tubule. Ischaemia for 30 or 60 min. induced glucosuria and phosphaturia, which was accompanied by polyuria and natriuresis. The Na(+)-dependent uptake of glucose, succinate and L-glutamate by brush-border membrane vesicles was not altered by 30 or 60 min. of ischaemia, while the H+/tetraethylammonium antiport was significantly inhibited after 30 min. of ischaemia. When the duration of ischaemia was extended to 120 min. the uptake of glucose and succinate by brush-border membrane vesicles was also significantly attenuated, but the L-glutamate uptake was not altered. The uptake of glucose, succinate and L-glutamate by basolateral membrane vesicles was not impaired even with 120 min. of ischaemia, suggesting that transport systems for organic compounds in the brush-border membrane are more sensitive to ischaemia than those in the basolateral membrane. Ouabain-sensitive oxygen consumption in renal cortical slices was not depressed by 60 min. of ischaemia. When kidneys were reperfused for 60 min. following 60 min. of ischaemia, the Na(+)-glucose and Na(+)-succinate cotransport and the H+/tetraethylammonium antiport were not different from the control, but the recovery of alkaline phosphatase was significantly reduced. When kidneys were subjected to ischaemia for 60 min., a loss of brush-border microvilli and plasma membrane was observed after 5 or 60 min. of reflow in the proximal convoluted tubule. After 3 hr of reflow, focal necrosis appeared although the microvilli were partially regenerated.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Effect of renal ischaemia on organic compound transport in rabbit kidney proximal tubule. 858 2

Post-reperfusion inflammation as well as anti-allograft response occur following kidney transplantation. We evaluated tissue damage by multiple renal indicators and searched for rejection predictors forewarning serum creatinine upturns. Twenty recipients (43 +/- 9 y; donors' age 35 +/- 16 y) of first renal grafts were studied. All through their hospital stay (35 +/- 18 d, range 17-75 d) we measured serum levels of urea, creatinine and electrolytes along with urinary excretion rates of total protein, albumin, enzymes (GGT, NAG, AAP) and electrolytes. During the period of observation, peaks were seen on the 1st day for serum creatinine, serum K+ and urine albumin output; on the 2nd day for urine Na+, GGT, AAP and protein excretion rates; on the 4th day for urea and creatinine outputs; on the 5th day for NAG output. On the 14th day, serum urea and creatinine as well as urine GGT, NAG, AAP, albumin and total protein were still elevated compared to 20 healthy control subjects. Delayed/slow graft function was observed in six recipients with higher pre-transplantation plasma lipids and lower donor HDL cholesterol. Hospital stay time was correlated with need for post-transplantation dialysis (p = 0.01) and recipient proteinuria by time 0 (TO) to day 3 (p = 0.02). Cold ischemia time was positively associated with 0-3 d serum creatinine, 0-3 d urinary urea and protein outputs (multiple r 0.9, p < 0.001). Multivariate analysis of longitudinal data showed that recipients' serum creatinine was positively correlated (p < 0.001) with urine AAP and negatively correlated with urine albumin, with diuresis volume and urine creatinine (p < 0.01). Serum creatinine elevations were preceded (previous 1-7 d) by increases in urinary indicators, the probability being higher in the presence of multiple simultaneous abnormalities. Useful parameters predictive of favorable graft outcome prior to transplantation included a brief cold ischemia time and a normal donor/recipient serum lipoprotein profile. Following transplantation, useful parameters were a high diuresis volume at time zero along with low urine NAG and high albumin outputs; early (first opst-graft 3 d) polyuria, low urea and GGT, high K, NAG and total protein excretions.
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PMID:Urinary excretion rates of multiple renal indicators after kidney transplantation: clinical significance for early graft outcome. 957 59

We examined the effect of temporary renal ischemia (30 min or 60 min) and reperfusion (1 day or 5 days) on the expression of renal aquaporins (AQPs) and urinary concentration in rats with bilateral ischemia-induced acute renal failure (ARF). Next, we tested whether reducing ischemia/reperfusion (I/R) injury by treatment with alpha-melanocyte stimulating hormone (alpha-MSH) affects the expression of AQPs and urine output. Rats with ARF showed significant renal insufficiency, and urinary concentration was markedly impaired. In rats with mild ischemic injury (30 min), urine output increased significantly to a maximum at 48 h, and then nearly normalized within 5 days. Consistent with this, semiquantitative immunoblotting revealed that kidney AQP1 and AQP2 abundance was significantly decreased after 24 h to 30 +/- 5% and 40 +/- 11% (n = 8) of controls (n = 9), respectively (P < 0.05). Five days after ischemia, AQP2 abundance was not significantly decreased and urine output was normalized. In contrast, severe ischemic injury (60 min) resulted in a marked reduction in urine output at 24 h, despite a significant decrease in urine osmolality and solute-free water reabsorption, T(c)H(2)O. AQP1 and AQP2 abundance was markedly decreased to 51 +/- 5% and 31 +/- 9% (n = 10) of controls (n = 8) at 24 h (P < 0.05). After 5 days, the rats developed gradually severe polyuria and had very low AQP2 and AQP1 levels [11 +/- 4% and 6 +/- 2% (n = 5) of controls (n = 8), respectively; P < 0.05]. A similar reduction was observed for AQP3. The reduction in AQP expression in the proximal tubule and inner medullary collecting duct was confirmed by immunocytochemistry. Next, we found that intravenous alpha-MSH treatment of rats with ARF significantly reduced the ischemia-induced downregulation of renal AQPs and reduced the polyuria. In conclusion, the I/R injury is associated with markedly reduced expression of the collecting duct and proximal tubule AQPs, in association with an impairment of urinary concentration. Moreover, alpha-MSH treatment significantly prevented the reduction in expression of AQPs and renal functional defects. Thus decreased AQP expression is likely to contribute to the impairment in urinary concentration in the postischemic period.
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PMID:Reduced abundance of aquaporins in rats with bilateral ischemia-induced acute renal failure: prevention by alpha-MSH. 1048 25

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