Allopurinol and enalapril failed to conserve urinary NOx and sodium in ischemic acute renal failure in spontaneously hypertensive rats.

BACKGROUND: Ischemia-reperfusion-induced acute renal failure (ARF) is associated with a high mortality in patients with hypertension and with an unfavorable outcome of kidney transplants from marginal donors. AIM: The influence of allopurinol and enalapril on urinary nitrate/nitrite (UNOx), glomerular filtration rate, plasma and urinary sodium, and hemodynamic parameters was examined in spontaneously hypertensive rats (SHR) with ARF. METHODS: ARF was induced by right-kidney removal and clamping the left renal artery for 40 min in 50 male 26-week-old SHR weighing 300 +/- 23 g. The rats were randomly allocated to five groups: (1) sham operated; (2) ARF; (3) ARF after pretreatment with 40 mg/kg allopurinol; (4) ARF after pretreatment with 40 mg/kg enalapril, and (5) ARF after pretreatment with 40 mg/kg allopurinol and 40 mg/kg enalapril. Creatinine clearance, UNOx (Griess reaction), cardiac output (dye dilution technique), mean arterial blood pressure, and renal blood flow were measured 24 h after reperfusion. Total vascular resistance and renal vascular resistance were calculated and compared between the groups. RESULTS: A nonsignificant decrease was found in both daily UNOx excretion and creatinine clearance when pretreated ARF groups and the ARF group without pretreatment were compared (p > 0.05). Significantly lower plasma sodium values (139.5 +/- 4.86 mmol/l) in the allopurinol-pretreated ARF group were found than in the ARF group without pretreatment, in the ARF group pretreated with enalapril, and in the sham SHR group (p = 0.029). The urinary sodium loss was greater in the enalapril-pretreated than in the allopurinol-pretreated ARF group (p = 0.047). Allopurinol and/or enalapril pretreatment decreased total vascular resistance (p = 0.003) in comparison with the sham SHR group. CONCLUSION: Neither allopurinol nor enalapril nor both were protective against ischemia-reperfusion injury in SHR, nor altered glomerular filtration rate and UNOx in a favorable direction.

An improvement in the outcome of acute renal failure.

BACKGROUND: Acute renal failure (ARF) requiring hemodialysis (HD) treatment is related to high mortality. The aim of this study was to analyze the influence of age, disease severity, and catabolism intensity on ARF outcome in patients requiring HD treatment during a 15-year period (1987-2001). METHODS: The retrospective, single-center study included 583 patients, 428 male, 155 female, age 49+/-15 years, treated by intermittent HD using cuprophane membranes with surface area of 1.3 m2. Liano's Acute Tubular Necrosis Individual Severity Score (ATNISS) score and Hypercatabolism Depuration Score (HDS) score were calculated to estimate disease severity and catabolism intensity in ARF patients. RESULTS: Average age of patients significantly increased during the 15-year period for more than one decade (44 to 55 years; p=0.0359), especially during the last five-year period (47+/-14.5 vs. 53+/-14.7, p=0.00015). Disease severity showed significant increase comparing periods 1992-1996 and 1997-2001 (ATNISS 0.385+/-0.197 vs. 0.437+/-0.208; p=0.00137), while catabolism intensity during these periods was similar (HDS 0.569+/-0.145 vs. 0.582+/-0.127; p=0.357). Despite the older and more severely ill population of ARF patients, mortality showed a sustained decrease during the 15-year period. Mortality in the period from 1987 to 1991 (49/83; 59%) was similar with the period 1992-1996 (chi2=0.44, p=0.5081), but significantly higher than in the period 1997-2001 (114/250; 45.6%; chi2=3.98, p = 0.0471). CONCLUSION: The results showed an improvement in the outcome of patients with ARF requiring HD treatment, despite increasing age, disease severity, and use of bioincompatible membranes.