Changes of mRNA and Plasma Levels of Atrial Natriuretic Peptide in Subtotal Nephrectomized Rats after High Salt Intake / 대한신장학회잡지

High salt intake produces volume expansion and electrolyte imbalance in chronic renal failure and modifies the synthesis and secretion of atrial natriuretic peptide(ANP) to compensate the abnormalities in fluid and sodium handling. This study was performed to investigate the effect of high salt intake on modulation of cardiac and noncardiac ANP mRNA as well as plasma ANP levels in 5/6 subtotal nephrectomized (NPX) rats as a model of chronic renal failure. Adult male Sprague-Dawley rats were divided into sham and NPX rats. NPX rats were induced by 2/3 pole ligation and contralateral nephrectomy. Sham and NPX rats had access to normal chow with tap water for 8 weeks or normal chow with 0.45% NaCl solution(HS) for last 2 weeks. Plasma ANP levels were measured by radioimmunoassay. ANP mRNA from the right atrium, left ventricle, hypothalamus and kidney were analyzed by RT-PCR with 32P-dCTP at 8 weeks after surgical operation in both sham and NPX rats. Blood urea nitrogen(BUN) was measured to evaluate impaired renal function. Body weight, daily water intake, hemoglobin, red blood cell, hematocrit, arterial pressure and heart rate were also monitored. Arterial pressure in NPX+HS rat was significantly increased. Both percent increase of body weight and hematologic findings were decreased in NPX rats. Daily water intake was increased in NPX rats, especially in NPX+HS rat. BUN also increased in NPX rats. Plasma ANP concentration was significantly increased in sham+HS rat, but other significant increases were not shown in NPX rats. The levels of right atrial ANP mRNA represented the increasing trend like as plasma ANP. Left ventricular ANP mRNA was increased in sham+HS rat, while the level in NPX+HS rat was decreased comparing with that of sham+HS rat. Hypothalamic ANP mRNA was decreased in NPX+HS rat. In the kidney, the level of ANP mRNA in sham+HS rat was increased comparing with sham rat, but ANP synthesis in NPX+HS rat was significantly lower than in sham, sham+HS and in NPX rats. These findings represent that the high salt intake in NPX rat does not alter the plasma levels and cardiac synthesis of ANP but suppresses the renal ANP mRNA. The diminished renal ANP synthesis may attenuate the regulatory role of ANP system in the kidney and result in volume expansion and hypertension.

Atrial mRNA and Plasma Levels of Atrial Natriuretic Peptides in Rats with Chronic Renal Failure / 대한신장학회잡지

The aim of this study was to assess the adaptive changes in plasma level of atrial natriuretic peptide(ANP) and its atrial mRNA expression in experimental rat model of chronic renal failure(CRF). Male Sprague-Dawley rats weighing 250-300g were divided into control rats, sham operated rats and 5/6 nephrectomized rats. CRF was induced by 5/6 nephrectomy, in that two thirds of the left kidney was ligated and the contralateral kidney was removed 1 week later. In the rats with 2/3 pole ligation, there were no significant changes in mean arterial pressure(MAP), heart rate, BUN and serum creatinine compared to sham operated rats. Expression of atrial ANP mRNA showed initially higher values and plasma renin activity(PRA) was lower than the sham operated rats. After 5/6 nephrectomy, MAP, heart rate, BUN and serum creatinine increased, and PRA showed the sustained lower values than the control rats. The changing pattern of plasma ANP level was similar to the that of ANP mRNA expression that showed biphasic peaks with the first increase at 1 to 3 days and the second increase at 28 days after nephrectomy. There were a significant positive correlation between plasma ANP level and MAP, and a negative correlation between plasma ANP and PRA. These results suggest that the secretion and the synthesis of ANP respond rapidly to the reduced renal mass, and ANP may play an important regulatory role during the renal adapting process in rats with experimental CRF.

Analysis of Risk Factors and Prediction of Mortality in Acute Renal Failure / 대한내과학회지

OBJECTIVES: Over the last 30 years, despite the increasing sophistication in medical care, the mortality of acute renal failure(ARF) has remained virtually unchanged at 40-50%, but the reasons remain unknown. This study intend to identify prognostic risk factors influencing survival and predict the mortality in ARF patients. METHODS: We retrospectively analyzed 152 patients with ARF who required renal replacement therapy, or whose serum creatinine level above 5 mg/dl, from Jan. 1988 to May. 1995. Multiple factors which may influence mortality were evaluated by univariate and multivariate analysis. RESULTS: 1) Of the 152 patients, 97 were male and 55 were female. The mean age was 47 years and the overall mortality was 36.8%. 2) Based on the univariate analysis, age>60 years, cause of ARF, APACHE II score, number of failing organs, peak serum creatinine level, PaO2, coma, hypotension, ARDS, GI bleeding, ventilatory support, need for antiarrhythmics, DIC, cardiovascular failure, pulmonary failure, neurological failure, and gastrointestinal failure were all significant factors discriminating between survivors and nonsurvivors(p<0.05) 3) By multivariate analysis, hypotension, coma, ventilatory support, and age over 60 years were significant independent predictors influencing survival in ARF patients and logistic equation and logit score were as follows : z=-2.04+1.32(age over 60)+2.18(hypotension)+2.88 (ventilatory support) + 3.28(coma) P=ez/(1+ ez) 4) In ROC(receiver-operating characteristic)curve, when the cutoff point was 0.2, maximum sensitivity was 75% and maximum specificity was 82%. CONCLUSION: In ARF, prognostic risk factors for mortality were age over 60 years, hypotension, assisted ventilation and coma. The logit score by multiple analysis is a reliable predictor of mortality in ARF patients, however the further studies are required to confirm these results.

A case of intracranial arterial thrombosis in nephrotic syndrome / 대한신장학회잡지

No abstract available.