ISSN:0886-022X    

DOI:10.3109/08860229609052770

出版商:Taylor&Francis    

年代:1996

数据来源: Taylor

摘要:

The properties of Ang II receptors in the aged kidney and their changes after acute renal ischemia are rarely known. The aim of this study was to examine the expression of Ang II receptor mRNA and characteristics of Ang II receptors in the aged kidney and to compare different responsiveness to 45 min of acute renal ischemia in young (3–4 months) and aged (23–24 months) rats. In the normal condition, ATI mRNA expression was much lower in the aged than that in the young rats. Maximal binding (Bmax) was also lower in the aged (1315±48 vs. 2035±257 fmol/mg, p<0.05). The dissociation constant (KD) of glomerular Ang II receptors, however, was significantly lower in the aged rats compared to the young (6.8±1.6 vs. 17.4±2.5 nM). After acute ischemia, the expression of ATI mRNA decreased in the young rats but increased in the aged rats. Interestingly, Bmaxof glomerular Ang II receptors was significantly increased in the aged ischemic rats (1852±94 vs. 1315±48 fmol/mg) with unchanged KD. These results show that: (a) the ATI mRNA expression and the Ang II receptor binding site are decreased with the aging process in the rat kidney; (b) the acute renal ischemia effect on different age groups has a greatly discrepant pattern in respect of Ang II receptor modulation, which may provide a potential therapeutic future for the receptor antagonists in acute renal ischemia in the aged.

ISSN:0886-022X    

DOI:10.3109/08860229609052771

出版商:Taylor&Francis    

年代:1996

数据来源: Taylor

摘要:

Use of ibuprofen in patients with asymptomatic renal failure is known to produce acute renal toxicity. One of the manifestations is interstitial nephritis of which the pathogenic mechanism remains unclear. In the present study, this nephrotoxic syndrome was induced in rabbits by giving a single dose of uranyl nitrate, followed by consecutive doses of ibuprofen. This animal model thus allowed the assessment of renal functional and pathological changes associated with ibuprofen use in renal insufficiency. In these rabbits, the major abnormality appeared to be confined to the tubulointerstitial compartment. Microscopic examinations of the renal necropsy specimens showed tubular necrosis and interstitial lymphocytic infiltration. The histological finding of lymphocytic aggregation suggests that this nephrotoxic effect stems from a cytotoxic immune reaction in the interstitium. Moreover, levels of renal 2-arylpropionyl-CoA epimerase, a key enzyme involved in the metabolic inversion of ibuprofen, showed a significant reduction, which may result from the massive destruction of the tubular cells in these animals. These results support the premise that renal insufficiency is a prerequisite factor for ibuprofen-induced interstitial nephritis.

ISSN:0886-022X    

DOI:10.3109/08860229609052772

出版商:Taylor&Francis    

年代:1996

数据来源: Taylor

摘要:

We evaluated the feasibility of magnetic resonance imaging (MRI)for early detection of tubular injury by monitoring changes in the apparent diffusion coefficient (ADC) of renal water in a rat model of myohemoglobinuric glycerol-induced acute renal failure (ARF). Diffusion-weighted MRI was performed concurrently with measurements of serum creatinine and blood urea nitrogen (BUN), evaluation of renal perfusion with dynamic contrast-enhanced MRI, and renal morphological examination. ADC values in the cortex and outer medulla significantly declined within minutes after the glycerol administration (70–75% of control at 4 min and 50–60% of control at 15 min). Contrast-enhanced MRI demonstrated renal hypoperfusion at 20 min after the onset of injury. Light microscopy showed normal glomeruli and edematous tubular epithelial cells at 10 and 30 min, with more severe swelling and protein casts at 30 min. No changes in serum creatinine or BUN levels were detected. We hypothesize that decrease in renal ADC may be attributed to renal ischemia and to subsequent intracellular accumulation of diffusion-restricted water. Similar imaging evaluation in other experimental models of ARF, and in patients, will define the diagnostic value of renal ADC changes in early detection of acute tubular injury.

ISSN:0886-022X    

DOI:10.3109/08860229609052773

出版商:Taylor&Francis    

年代:1996

数据来源: Taylor

摘要:

Acute renal failure (ARF) was induced in rats by intramuscular injection of 50% glycerol, 10 mL/kg body weight. Rats were given isotonic saline (1.5 mL/h) dopexamine hydrochloride (dopexamine, 100μg/h) or dopamine (100μg/h), commencing either immediately after glycerol administration and maintained during all the observation time (90 min, acute studies) or 20 min before administration of glycerol and during 60 min (chronic studies). Renal function was assessed during 90 min after induction of ARF in anesthetized rats and during 3 days following ARF induction in conscious animals. In anesthetized rats treated with dopexamine or dopamine, the reduction in inulin and para-aminohippuric acid clearance was markedly lower than that observed in untreated animals. In conscious animals, urinary flow and creatinine clearance were higher in rats treated with dopamine or dopexamine than in the non-treated group. Rats treated with dopexamine had higher renal Na+and K+excretion than dopamine-treated rats. Survival was higher in the dopexamine group than in either of the other two groups. These results demonstrate that pretreatment with dopexamine or dopamine significantly improves the course of ARF, with better survival after treatment with dopexamine.

ISSN:0886-022X    

DOI:10.3109/08860229609052774

出版商:Taylor&Francis    

年代:1996

数据来源: Taylor

摘要:

Hyperosmolality in renal medulla inhibits functions of polymorphonuclear leukocyte (PMN) such as phagocytosis, intracellular killing, and superoxide generation. The main factors of hyperosmolality in the renal medulla are thought to be urea and NaCl. We studied the luminol-dependent chemiluminescence (CL) response of PMNs to three different stimulators: phorbol myristate acetate (PMA), formyl-methionyl-leucyl-phenylalanine (FMLP), and opsonized zymosan (OZ). When PMNs were incubated or preincubated with hyperosmotic urea or NaCl solutions, CL responses were significantly reduced following stimulation by each of PMA, FMLP, or OZ. Reduction of CL response was concentration and osmolality dependent in hyperosmotic urea and NaCl solution. These results suggest that respiratory burst and production of active oxygen species of PMNs through three different signal transduction pathways are inhibited in hyperosomotic conditions comparable to the renal medulla.

ISSN:0886-022X    

DOI:10.3109/08860229609052775

出版商:Taylor&Francis    

年代:1996

数据来源: Taylor

摘要:

Serum levels of sICAM-1 and sVCAM-1 adhesion molecules as well as TNF cytokine were measured in 50 kidney transplant recipients [14 patients with stable graft function, 18 patients with acute rejection, 10 patients with CsA toxicity, 6 patients with ATN, and 2 patients with cytomegalovirus (CMV) disease] during the first 3 postoperative weeks. All the patients studied showed, on the first posttransplant day, elevated serum levels of sICAM-1 (260±53 ng/mL). Interestingly, all the patients with good graft function presented thereafter a reduction of slCAM-1 serum levels close to the normal values (185.2±40 ng/ mL). In contrast, the group of patients with acute allograft rejection showed significantly increased serum levels of slCAM-1 (371.5±86 ng/mL; p<0.001), 3–4 days before diagnosis of acute rejection. Although sVCAM-1 levels were increased in both acute graft rejection (2263±106) and CsA toxicity (1650±315) patients, such increase was not significant among either group of patients when the group with CsA toxicity was compared with either ATN (1320±204) or stable renal function (1089±167). No statistical differences in the levels of TNF were demonstrated between the different groups of patients studied. Our findings demonstrate that quantitative determination of serum slCAM-1 may be of predictive clinical value in transplanted patients with acute renal allograft rejection.

ISSN:0886-022X    

DOI:10.3109/08860229609052776

出版商:Taylor&Francis    

年代:1996

数据来源: Taylor

摘要:

Fifteen patients with unilateral functioning arteriovenous fistula were assessed clinically and electromyographically to identify local neurologic changes. Ten of the patients were symptomatic (motor and/or sensory) and 5 were asymptomatic. Clinically, 11 patients had signs of a mild polyneuropathy, 2 patients of ulnar neuropathy, and 1 patient had signs of median neuropathy. A decrease of the above-elbow ulnar conduction velocity was noted in the study group on the side of the functional fistula, and in the symptomatic patients only on the side of the nonfunctional/nonexisting fistula. We suggest that ulnar nerve vulnerability should be taken into consideration during construction of the fistula, as well as during dialysis.

ISSN:0886-022X    

DOI:10.3109/08860229609052777

出版商:Taylor&Francis    

年代:1996

数据来源: Taylor

摘要:

Oral L-carnitine has been reported to lower the elevated serum myoglobin of renal failure in chronic peritoneal dialysis patients, and intravenous L-carnitine can improve muscle fatigue and cramps in chronic hemodialysis patients. In this study oral L-carnitine, 1.98 g/day, was administered to 6 chronic hemodialysis patients for 8 weeks. Serum levels of myoglobin, creatine kinase, and aldolase, as well as skeletal muscle symptoms (cramps during dialysis, fatigue, and weakness) were monitored biweekly for 12 weeks. Mean baseline serum myoglobin level was 337±34 ng/mL. By 6 and 8 weeks mean serum myoglobin was 234±39 and 233±40 ng/mL, significantly lower by the Friedman test (p<0.05). Four weeks after carnitine was discontinued, mean serum myoglobin had risen to 320±118 ng/mL. Serum creatine kinase and aldolase levels were normal throughout the study. All 6 patients noted improvement in muscular symptoms, with maximal effect at 8 weeks, although 2 patients did not improve until 2 to 4 weeks after carnitine was stopped. We conclude that oral L-carnitine may lower serum myoglobin and improve muscle cramps and weakness in hemodialysis patients. The maximal effect of carnitine on myoglobin occurs 2 weeks before the maximal improvement in muscular symptoms.

ISSN:0886-022X    

DOI:10.3109/08860229609052778

出版商:Taylor&Francis    

年代:1996

数据来源: Taylor

摘要:

We analyzed the case records of 19 patients diagnosed to have drug-induced acute interstitial nephritis to assess the clinical profile and role of steroids in renal recovery, and to correlate histological features to outcome. Patients with underlying glomerular diseases, malignancy, obstructive nephropathy, or systemic infections were excluded. Nonsteroidal anti-inflammatory drugs alone accounted for 6 cases (group A), whereas antibiotics were the major offender in the remaining patients (group B). In 13/19 (69%) cases, renal failure was severe enough to require dialytic support. Overall 14/19 (74%) of the patients recovered normal renal function within 6 weeks of withdrawal of the offending drugs. Neither the extent of renal recovery nor the time required for it was altered by oral steroids. Tubular atrophy and interstitial fibrosis adversely affected renal recovery. Oliguria, tubular necrosis, interstitial edema, and the density/distribution of interstitial infiltrate did not have any effect on the rate/ extent of renal recovery.

ISSN:0886-022X    

DOI:10.3109/08860229609052779

出版商:Taylor&Francis    

年代:1996

数据来源: Taylor