Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0022116 (ischemia)
 91,303 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Rats pretreated with sodium bicarbonate were functionally protected from the damage of bilateral renal artery occlusion. The rise in serum creatinine (day 1 minus day 0) during the first 24 h after ischemia was 2.88 +/- 0.28 mg% in the bicarbonate-loaded animals versus 3.90 +/- 0.26 mg% in their matched controls (p less than or equal to 0.01). Pretreatment with acetazolamide produced a similar alkaline urine as the bicarbonate loading (pH 8.3 vs. 7.0 in controls) and a similar degree of protection (delta creatinine 2.85 +/- 0.41 vs. 4.23 +/- 0.26 mg%; p less than or equal to 0.01). A direct effect of sodium loading was excluded by comparing NH4HCO3 with NaHCO3 loading and observing no difference in delta creatinine levels after ischemia (3.39 +/- 0.69 vs. 3.20 +/- 0.61 mg%). These data indicate that NaHCO3 protects in this model of acute renal failure and further suggest that the mechanism of protection is not related to either systemic alkalosis or sodium loading.
Nephron 1986
PMID:Effect of sodium bicarbonate preloading on ischemic renal failure. 301

The present work was performed on uninephrectomized rabbits recovering from ischemic acute renal failure (ARF) in an attempt to elucidate whether or not intraglomerular events are a determinant factor in the development of resistance to ARF. 14 days after a 2-hour clamping of the renal artery (the recovery phase), the animals did not show resistance to an additional ischemia. On the other hand, glomeruli derived from normal kidneys displayed a contractile response to angiotensin II, arginine vasopressin or norepinephrine in Eagle's minimum essential medium, whereas glomeruli from rabbits recovering from ischemic ARF were refractory to the vasoconstrictor agents. The findings suggest that glomerular refractoriness to contractile stimuli does not provide resistance to an additional renal ischemia in the ischemic model of ARF.
Nephron 1988
PMID:Glomerular refractoriness to contractile stimuli in rabbits recovering from ischemic acute renal failure. 336 77

Prior acute renal failure (ARF) induced by either glycerol (G) or mercury provides protection against rechallenge with the same agent or the other. To ascertain whether the widely employed ischemic renal failure model also shares a similar pathogenesis, two protocols were designed. In the first protocol, unilaterally nephrectomized rats with or without a prior episode of G-induced ARF two weeks previously were subjected to an ischemic insult [60-min total left renal artery clamp (LRAC)]. At 24 or 48 h after LRAC there was no difference in renal function in the rats with or without prior ARF. In the second protocol the sequence of G and ischemia was reversed. In rats having undergone LRAC two weeks prior to G, glomerular filtration rate was virtually identical from the right (control) and left (prior ARF) kidney (right, 138 +/- 30; left, 101 +/- 22 microliter/min/100 g body weight), and not different from rats receiving G alone. We conclude that protection against ARF conferred by prior insult is not a feature of all models.
Nephron 1987
PMID:Protection against acute renal failure by prior acute renal failure: differences between myohemoglobinuric and ischemic models. 368 91

90 min of renal artery occlusion in previously unilaterally nephrectomized rats produce acute renal failure (ARF) (plasma creatinine at 48 h after ischemia: 636 +/- 44 vs. 133 +/- 9 mumol/l in controls). Between 1 and 48 h after releasing the occlusion, two populations of superficial nephrons could be observed, one with dilated tubules and elevated proximal tubular pressures (PTP: 39 +/- 1 vs. 12 +/- 1 mm Hg in controls) and the other with collapsed tubules and decreased PTP (9 +/- 1 mm Hg). Proximal tubular passage time (PPT) could not be determined with the Lissamine green technique. Seven methods of pretreatment were tested, 5 of which provided partial functional protection (DOCA/NaCl/NaCl, furosemide infusion, inosine bolus, mannitol bolus and the combination of the last two). Neither renal renin levels nor urinary NaCl excretion were consistently correlated with protection. Functionally protected rats consistently showed no PTP increase and normal PPT in the tubules at the kidney surface. However, plasma creatinine at 48 h differed markedly within the 5 protected groups, ranging from 168 +/- 18 to 398 +/- 35 mumol/l. Extensive medullary congestion was seen at 1-6 h after ischemia only in those rats with obstructed, high pressure nephrons at the kidney surface. To conclude: (1) Functional protection from ischemic ARF, both with and without an accompanying increase in solute excretion, was achieved by the abolition of tubular obstruction. (2) Despite similar degrees of restoration of superficial nephron function, the persisting impairment of whole kidney function differed markedly between the protected groups. (3) Impairment of deeper nephron function must therefore play a major role, perhaps through persisting obstruction in the long loops of Henle. (4) High pressure nephrons may compromise medullary venous outflow in the outer zone of the outer medulla.
Nephron 1982
PMID:Superficial nephron obstruction and medullary congestion after ischemic injury: effect of protective treatments. 675 72

It is concluded that the condition of 'acute renal failure' starts in the first minutes after restoration of the circulation, following the ischemic period. The aggregation of red blood cells in the renal medulla with the subsequent cessation of medullary blood flow represents an important factor causing both the reduced urinary concentrating ability and the depressed urinary potassium concentration. The persisting medullary ischemia leads to cellular swelling and eventually to cell necrosis, which in turn results in a mechanical obstruction of the tubular lumen in the region of the loops of Henle and the medullary collecting ducts. In contrast, the anuria which is evident weeks after the primary damage, seems to be caused by the release of vasoconstrictor principles, whose origin is unclear, but it seems not to be mediated via the renal nerves, since the same symptoms are found in transplanted kidneys. Therapeutic endeavors using heparin, saline expansion and mannitol to improve the rheological characteristics of the blood seems to be of limited value. Infusion of hyperoncotic albumin during the ischemic period, however, seems to be of some benefit, since glomerular filtration is better preserved. The addition of ATP and magnesium, glucose or adjustment of the acid base status with buffers has not been encouraging in the present models, in which glomerular filtration rate is reduced to only a few percent of control.
Nephron 1982
PMID:Hemodynamic alterations in ischaemic acute renal failure. 717 66

We investigated electrocardiographic changes occurring after hemodialysis in 20 male patients with chronic renal failure. Changes in the configuration of T wave, ST segment and R wave consistent with ischemia were found in 30, 45, and 75%, respectively. Contrary to prior speculation the R wave height did not vary with the volume changes of body fluid occurring in dialysis. It is concluded that ischemic-appearing changes of uncertain significance are common in the postdialysis population.
Nephron 1981
PMID:Electrocardiographic changes following dialysis. 726 8

The technical results of 259 nephron sparing operations for renal cell carcinoma or renal oncocytoma were reviewed. Local or renal related complications occurred after 78 procedures (30.1%). The incidence of complications was less for operations performed after 1988 (22% versus 37%, p = 0.009) and for incidentally detected versus suspected tumors (p = 0.009). The most common complications were urinary fistula formation (45 operations) and acute renal failure (33). Significant predisposing factors for urinary fistula formation included central tumor location (p = 0.001), tumor size greater than 4 cm. (p = 0.001), the need for major reconstruction of the collecting system (p = 0.001) and ex vivo surgery (p = 0.001). Only 1 urinary fistula required open operative repair, while the remainder resolved either spontaneously (30) or with endoscopic management (14). Significant predisposing factors for acute renal failure included a solitary kidney (p = 0.001), tumor size greater than 7 cm. (p = 0.008), greater than 50% parenchymal excision (p = 0.001), greater than 60 minutes of ischemia time (p = 0.035) and ex vivo surgery (p = 0.001). Acute renal failure resolved in 28 patients, of whom 9 required temporary dialysis, while 5 required permanent dialysis. Overall, 8 complications (3.1%) required repeat open surgery for treatment while all other complications resolved with noninterventive or endourological management. Surgical complications contributed to an adverse clinical outcome in only 7 patients (2.9%). Nephron sparing surgery can be performed safely with preservation of renal function in most patients with renal tumors.
 ...
PMID:Complications of nephron sparing surgery for renal tumors. 815 54

Normal and streptozotocin diabetic rats were subjected to ischemic injury by unilateral renal artery occlusion for 60 min. The cortical and the medullary oxygen consumption (QO2) in the postischemic and the control, contralateral nonischemic, kidneys were measured 1 h, 1 day, and 1, 2 and 4 weeks for normal rats and 1 day, and 1 and 4 weeks for diabetic rats after ischemia. The effects of furosemide on QO2 of the cortex and the medulla of normal and diabetic rats were studied. The diabetic kidney was more vulnerable to ischemic injury than the normal kidney. Furosemide-sensitive active transport function in the medulla of the diabetic kidney was higher than that of the normal kidney. Furosemide did not decrease the cortical QO2 significantly in the control and the postischemic kidneys of normal and diabetic rats. In contrast, the medullary QO2 of the control kidney in both rats was significantly reduced by furosemide at every period after ischemia. In the medullary QO2 of the postischemic kidney, there were no significant decreases at any period after ischemia in the diabetic rats and only after a 1-hour period for normal rats. However, 4 weeks after ischemia, there was no statistically significant difference in the medullary QO2 inhibition by furosemide between the control and the postischemic kidneys in both normal and diabetic rats. We conclude that the furosemide-sensitive active transport function in the medulla recovers by the 4th week after ischemia in normal and diabetic rats.
Nephron 1993
PMID:Effects of furosemide on renal oxygen consumption after ischemia in normal and streptozotocin diabetic rats. 834 90

The aim of the present study was to examine the effect of exposing animals to 100% oxygen instead of room air on renal function and endogenous antioxidant enzymes of the postischemic reperfused rat kidney. Superoxide dismutase (SOD), catalase and glutathione peroxidase (GPX) were determined in the homogenate of the left kidney after 45 min of ischemia, caused by clamping the left renal artery, 10 and 90 min after reperfusion while the animals breathed room air or 100% O2. The right kidney served as a control. The possible influence of trapped blood in the clamped kidney was also investigated by the use of a correction factor based on the Hb concentration in the homogenate. The results indicate that such correction is necessary as the blood adds significant antioxidant activity. The activities of all 3 enzymes after 45 min of ischemia decreased significantly in the left (ischemic) compared to the right (control) kidney, to 64% of the control levels for catalase, 58% for SOD and 49% for GPX. After 10 min of reflow, a further decrease in the activities of catalase (to 49%) and of GPX (to 29%) was found. SOD activity, however, increased to 64%. After 90 min of reperfusion, restoration toward normal levels was noticed (SOD activity increased to 70%, catalase to 76% and GPX to 58%). Breathing 100% O2 resulted in a significant decrease in all enzyme activities (to 38.6% for catalase, 45% for SOD and to 27.4% for GPX). This inactivation can be explained by increased reactive oxygen species (ROS) activity during hyperoxia.(ABSTRACT TRUNCATED AT 250 WORDS)
Nephron 1993
PMID:Effect of oxygen tension on activity of antioxidant enzymes and on renal function of the postischemic reperfused rat kidney. 845 Sep 13

The present study was designed to determine whether the administration of free radical scavengers, superoxide dismutase (SOD), catalase or dimethylsulfoxide (DMSO) is able to ameliorate ischemia/reperfusion injury in the canine kidney and also ascertain whether or not a relationship exists between oxygen free radicals and membrane-bound Na(+)-K(+)-ATPase activity. In 23 dogs, the vascular pedicle of the left kidney was clamped for 75 min at room temperature. The experimental animals received free radical scavengers for 30 min starting at 2 min prior to reperfusion. Renal tissue specimens were enzyme-histochemically examined regarding the activity of membrane-bound Na(+)-K(+)-ATPase, and a marked reduction just before reperfusion was revealed. The SOD- and the DMSO-treated groups showed a marked recovery of the membrane-bound Na(+)-K(+)-ATPase activity; however, the untreated and the catalase-treated groups still demonstrated a marked reduction 1 day after reperfusion. At the same time, widespread acute tubular necrosis in the cortex was observed in the untreated and catalase groups in comparison with the SOD and the DMSO groups. In addition, the SOD and the DMSO groups significantly preserved better renal function. Based on these findings, it was thus concluded that free radical scavengers ameliorate the recovery of depressed membrane-bound Na(+)-K(+)-ATPase activity and ischemia/reperfusion injury in the canine kidney.
Nephron 1996
PMID:The influence of oxygen free radical scavengers on the reduction of membrane-bound Na(+)-K(+)-ATPase activity induced by ischemia/reperfusion injury in the canine kidney. 873 Apr 34


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