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

This study was designed to determine changes in one metabolic function, gluconeogenesis (GLG), after ischemic renal injury. Tubule suspensions were prepared by collagenase treatment of SD rat kidneys on 1, 3, and 7 days after left renal artery and vein occlusion for 0-90 min and incubated in Krebs-Henseleit buffer with or without 2 mM pyruvate or malate aerobically. Glucose contents were assayed photometrically. On days 1 and 3 after ischemia for longer than 60 min, serum creatinine levels rose significantly. The tendency of increase of GLG was observed on days 1 and 3 after 10-60 min of ischemia. GLG increased significantly on day 1 after 30-min ischemia. On the other hand, GLG decreased significantly on day 1 after 90-min treatment. Morphologic damage was limited to the corticomedullary region on days 1 and 3 after ischemic times of 30 and 60 min. These results suggest that renal GLG is stimulated to supply energy for ATP decrease by ischemia and for further regeneration in extraproximal segments along the nephron.
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PMID:Alterations of gluconeogenesis by ischemic renal injury in rats. 146 98

In order to evaluate the role of nifedipine in the nephrotoxic effect induced by both ischemia and CyA, 18 healthy mongrel dogs were used. The kidneys were exposed and subjected to 1 h of ischemia by clamping both renal vessels. To the renal artery of the first group of kidneys (n = 9), 300 mL of cold Euro-Collins solution, in which nifedipine (Bay a 1040-10 mg) was diluted, was infused for 15 min (nifedipine group), while 300 mL of cold Euro-Collins solution plus 10 mg of placebo (Bay a 1040-placebo) was infused to the renal artery of the second group (n = 9) of kidneys (placebo group). Venous drainage was effected through a plastic cannula. All animals received through a nasogastric catheter 20 mg/kg cyclosporine A at the beginning of the ischemia. The 1 h of ischemia was divided in a 15-min period of cold ischemia and 45-min of warm ischemia, at the end of which the clamps were removed. During the 2 h (30 min x 4) after reperfusion, 10 mg of nifedipine and placebo was administered additionally by a peripheral vein to the nifedipine and the placebo group, respectively. Then the kidneys were removed for histological study. Urine volume and creatinine and urea clearances of the nifedipine group were significantly higher than the placebo group (p < 0.001) while TxB2 levels were higher in the placebo group in all studied periods (p < 0.001). Urine sodium, FENa, osmolar clearance, and LDH values were significantly different (p < 0.01), but the urine potassium concentration was not different in the two groups.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Reduction of CyA nephrotoxicity by nifedipine during and after experimental in situ renal preservation. 146 99

The ability of prostaglandins to protect the kidney against ischemic and toxic renal injury was evaluated by in vivo and in vitro models of renal ischemia. The prostaglandin E1 analogue, misoprostol, was found to provide significant protection against ischemia-induced renal dysfunction in rats subjected to 40 minutes of renal artery occlusion. Misoprostol-treated rats had glomerular filtration rates almost threefold greater than control animals, although renal blood flow and renal vascular resistance were not significantly different. Improved tubular function was reflected in a lower fractional excretion of sodium and a higher urine-to-plasma creatinine ratio. Misoprostol also provided similar protection in a model of toxic renal injury produced by mercuric chloride. In an in vitro model employing primary cultures of proximal tubule epithelial cells subjected to hypoxia and reoxygenation, misoprostol limited cell death. Posthypoxic cells had apical membrane disruption and loss of microvilli when examined by transmission electron microscopy. These changes were not seen in misoprostol-treated cells. The "cytoprotective" effect was also produced by prostaglandin E2 and prostacyclin. The ability of prostaglandin E to protect against toxic and ischemic renal injury did not appear to be due to an antioxidant effect because misoprostol did not limit lipid peroxidation in vivo and did not protect against oxidant injury by tert-butyl hydroperoxide in vitro. Although the exact mechanism of prostaglandin protection was not revealed, these studies demonstrate that prostaglandins protect renal tubule epithelial cells from hypoxic injury at the cellular level independent of hemodynamic factors or inflammatory responses. Such a "cytoprotective" effect of prostaglandins may be a generalized phenomenon since it has also been demonstrated in gastrointestinal epithelium.
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PMID:Prostaglandins protect kidneys against ischemic and toxic injury by a cellular effect. 147 66

The hypothesis that dietary fish oil would protect dogs from ischemic acute renal failure was tested. Fish oil (eicosapentaenoic acid, 55 mg/kg per day, and docosahexaenoic acid, 40 mg/kg per day was given to eight instrumented, female, beagle dogs for 6 wk, while seven control dogs received vehicle. After 3 wk, unilateral nephrectomy was performed and a pneumatic cuff with flow probe was placed around the remaining renal artery of each dog. Three weeks thereafter, the cuff was inflated for 120 min. Renal function, RBF, and prostanoid excretion were measured 24 and 72 h after ischemia. In dogs receiving fish oil, blood pressure, GFR, RBF, renal vascular resistance (RVR), cholesterol, triglycerides, and prostanoid excretion were measured weekly for 6 wk. Further, cytosolic calcium was measured before and five times after fish oil. Blood pressure decreased, serum cholesterol and triglycerides decreased, and the cytosolic calcium within platelets decreased. The urinary excretion (expressed as picograms per milligram of creatinine) of the thromboxane (TX) metabolite TXB2 and the excretion of prostaglandin (PG)E2, as well as the excretion of the PGI2 metabolite 6-keto PGF1 alpha were decreased. GFR, RBF (Cl inulin and Cl para-aminohippuric acid), and RVR were not influenced by fish oil. Unilateral nephrectomy decreased GFR and RBF and increased RVR as expected, whereas it further decreased prostanoid excretion. Acute renal ischemia caused a significant, reversible decrease in GFR and urine volume in vehicle-treated animals, whereas no significant effect on renal function or urine volume was observed in animals pretreated with fish oil.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Amelioration of ischemic acute renal failure by dietary fish oil administration in conscious dogs. 147 27

Aortic and renal vascular reconstruction often involve significant renal ischemia. Profound hypothermia during renal ischemia preserves renal tissue. However, in the clinical setting of vascular reconstruction specific attempts at cooling the kidney are often impractical, and renal ischemia frequently occurs at physiologic temperatures. This study demonstrates that minimal temperature changes during renal ischemia alter the functional and morphologic outcome. Rats anesthetized with halothane underwent a right nephrectomy and placement of a snare around the left renal pedicle for 45 minutes to produce renal ischemia. Seventy-five adult male Sprague-Dawley rats, weighing 250 to 350 gm were divided into three groups based on the body temperature maintained during renal ischemia (35 degrees C, 37 degrees C, 39 degrees C). Body temperature was continuously monitored with a rectal thermistor and maintained by adjustment of a heating pad and lamp. Two postischemic protocols were followed including a creatinine assessment protocol with blood samples collected at 24, 48, and 72 hours and a histologic assessment protocol with biopsy of the kidney at 30 hours. At 24 hours after ischemia plasma creatinine concentrations were increased in rats with elevated body temperatures (35 degrees C vs 37 degrees C; [p = 0.001], 37 degrees C vs 39 degrees C; [p = 0.150]). The 30-hour histologic assessment indicated a difference in morphologic outcome (35 degrees C vs 37 degrees C; [p = 0.063], 37 degrees C vs 39 degrees C; [p = 0.016]), with proximal tubular morphology being better maintained at lower temperatures.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Minimal physiologic temperature variations during renal ischemia alter functional and morphologic outcome. 156 May 50

The prognostic significance of early malfunction or delayed function after cadaveric renal transplantation is controversial. This study examines the influence of intraoperative management in 438 cadaveric renal transplant recipients on seven posttransplant outcome measures: (1) time of onset of urine output, (2) urine volume, (3) renal function, (4) incidence of delayed function, (5) never-functioning kidney, (6) graft survival, and (7) patient survival. Delayed function, defined as the need for hemodialysis during the first posttransplant week, decreased from 46% in 1982 to 15% in 1990 and was associated with a 25% lower 1-year graft survival rate and a mortality rate of 10% at 3 months, compared with 3% when immediate function was present. The most important factors influencing the outcome were cold ischemia time (P = 0.007), intraoperative administration of albumin (P = 0.0027), duration of surgery (P = 0.020), and recipient age (P = 0.041). A high albumin dose (1.2-1.6 g/kg bodyweight) induced urine output within 30 min in 75% of patients and induced larger urine volumes (7.3 L/24 hr), as compared with the effects of a low dose (0-0.4 g/kg), which induced urine output within 30 min in 39% and only 3.7 L/24 hr. Serum creatinine at 1 week was 3.4 and 5.8 mg/dl for the high and low albumin doses, respectively (P less than 0.0001). Similarly, mean glomerular filtration rates at 1 and 7 days were 33 and 21 ml/min, compared with 47 and 28 ml/min, for the high and low albumin doses, respectively (P less than 0.01). The incidence of delayed function and of never-functioning kidneys declined from 34% and 9% for the low dose to 12% and 1% for the high dose, respectively. Finally, with increasing albumin dose, the graft survival rate at 1 year improved from 59 to 78% (P less than 0.002), and the patient mortality rate at 3 months dropped from 6% to 2%. For albumin dose intervals between the high (1.2-1.6 g/kg) and low (0-0.4 g/kg), the effect on all seven outcome measures was intermediate, generally describing a linear relationship. Weighted least-squares analysis of the relationship of delayed function with high vs. low doses of albumin, mannitol, furosemide, and volumes of crystalloid solutions showed significance only for the albumin effect. High-dose albumin infusion likely produces intravascular volume expansion and achieves a prompt restoration of blood flow, minimizes hypoxic injury, and helps preserve renal tissue. The possibility of other beneficial effects of albumin unrelated to intravascular volume also exists.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Intraoperative albumin administration affects the outcome of cadaver renal transplantation. 156 43

The effect of prolonged ischemia time on the generation of chronic rejection was investigated in long-surviving rat renal allografts. Three groups of rats were compared: allografts with a 30-min ischemia time, allografts with a 60-min ischemia time, and syngeneic grafts with a 60-min ischemia time. All transplants were initially immunosuppressed with 5 mg/kg/day of cyclosporine i.m. for 3 weeks postoperatively. The CsA trough levels were similar in the three rat groups. All groups demonstrated an initial rise and fall in serum creatinine; a simultaneous biopsy confirmed acute CsA toxicity. Thereafter the serum creatinine level remained on the normal control level both in the 30-min ischemia allografts and in the 60-min ischemia syngeneic grafts. After the initial decline, the serum creatinine level steadily increased in the 60-min ischemia allograft group and was 181 +/- 64 mumol/L at the end of the observation period, 12 weeks postoperatively, compared with 85 +/- 21 mumol/L in the 30-min ischemia allografts and 89 +/- 25 mumol/L in the 60-min ischemia syngeneic grafts. Quantitative histology that was performed upon autopsy demonstrated that the 60-min ischemia allografts showed persistent inflammation, inflammatory cell pyroninophilia, vascular arteriosclerosis and obliteration, and glomerular sclerosis, which were significantly stronger than in similarly immunosuppressed syngeneic transplants. Reduction of the ischemia time from 60 to 30 min significantly ameliorated the vascular and glomerular changes in the allografts but not the inflammatory alterations. This experimental study confirms previous clinical observations and demonstrates that prolonged ischemia contributes to chronic rejection in renal allografts. The results suggest that the effect of prolonged ischemia on chronic rejection is directed primarily to the parenchymal components of the graft, possibly to the graft vascular endothelium. As prolonged ischemia did not significantly affect the inflammation in the transplants, we conclude that the effect is not directed to the intensity of the host antigraft immune response.
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PMID:Chronic rejection of rat renal allografts. II. The impact of prolonged ischemia time on transplant histology. 156 48

With the recent increase in the number of liver and pancreas transplants being performed in Europe, many groups have found it necessary to develop techniques for the combined harvesting of whole pancreaticoduodenal and liver grafts. To date we have carried out a total of 35 multiorgan procurements including liver, heart, pancreas, and kidneys. In ten cases we reconstructed the arterial supply of the pancreas with an end-to-end anastomosis between the proximal splenic artery and the distal end of the superior mesenteric artery (SMA), and in eight patients we used a donor Y-iliac graft. Patients were monitored postoperatively by determination of BUN, serum creatinine, blood glucose, serum and urinary amylase levels, and Doppler assessment of the graft was carried out at regular intervals. Mean ischemia/preservation time in both groups was 6 h. All simultaneous kidney and pancreas transplants functioned well initially with none of the patients requiring dialysis. All patients were insulin-free immediately after surgery. One patient in the splenomesenteric group developed venous thrombosis of the graft, requiring removal of the gland, but has subsequently been successfully retransplanted. All remaining patients have been insulin-free for 1-14 months. One patient in the Y-iliac group also developed venous thrombosis of the graft, but all remaining patients in this group have been insulin-free for 1-12 months after transplantation.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Combined whole pancreas and liver retrieval: comparison between Y-iliac graft and splenomesenteric anastomosis. 158 Sep 87

We studied the pre operative status and the 1st, 4th, 12th and 24th hours of the post operative period after open heart surgery with cardiopulmonary bypass with a crystalloid solution containing 10 gr of mannitol. We considered acute renal failure (ARF) as being any increase in plasma creatinine values of 0.25 mg/dl for the first 24 hours and 0.5 mg/dl for periods longer than 24 hours. Six patients had transitory ARF (28.5%). The maximum value of plasma creatinine was 2.3 mg/dl and no patients required renal function substitution. There were no deaths. We used as ischemia ARF indicators the urinary flow rate, urine/plasma creatinine ratio, urine/plasma osmolality ratio, sodium fractional excretion and free water reabsorption. We also measured the urinary N-A-Glucosaminidase (NAG). We found that creatinine clearance reached its lowest in the first and fourth hours. Beyond the fourth hour we observed, the urinary flow rate reduce significantly, the urine/plasma creatinine and osmolality ratios reach values traditionally associated prerenal ARF, an increase main free water reabsorption and a decrease in sodium fractional excretion with a close relationship between the less than 1 value and the increase in plasma creatinine. There was a significant NAG increase in the 24 th hour. The evidence of a vulnerability period for renal ischemic lesions between the 4 th and 12 th hour suggests a second mannitol administration during the first four hours of the post operative period.
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PMID:[Identification of a period of renal ischemic vulnerability studying the changes in the indicators of acute renal insufficiency after heart surgery with extracorporeal circulation]. 160 64

Blood pressure monitoring of hypertensives in the ambulatory state by automated portable devices (ABPM) as compared with casual office readings (COBPM) may predict outcome with greater precision and at an overall lower cost. Prospective trials that in random fashion require evaluation and management decisions on the basis of ABPM compared with COBPM are required to determine whether the above is true. End points such as death, stroke, or myocardial infarction occur at a low frequency rate. This would require thousands of patients to be followed 5 or more years to determine if evaluation and management by ABPM compared with COBPM results in a different outcome. A much smaller population can be used if end points are changes in left ventricular mass and left ventricular ischemia, arterial wall stiffness and thickness, endogenous creatinine clearance, renal albumin excretion, antihypertensive drug requirements, and adverse reactions. Until results from such a prospective trial are available, COBPM is the method of choice for evaluation and management of hypertensives. Automated blood pressure measurement can provide useful information in special circumstances and is of value for research purposes.
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PMID:Ambulatory blood pressure monitoring for evaluation and management of hypertensives: effect on outcome and cost effectiveness. 163 98


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