摘要:

Evidence from previous theoretical and experimental studies has indicated that angiotensin formed as a result of unilateral kidney disease will not produce chronic hypertension unless there is also a sodium and fluid retaining effect on the otherwise normal contralateral kidney. Therefore, the present experiments were conducted in dogs to determine whether or not blood angiotensin concentrations similar to those found in patients with unilateral kidney disease can cause significant water and salt retention by a normal dog kidney. Angiotensin was perfused directly into the renal artery of a semi-isolated perfused kidney preparation, and the effects on renal blood flow, glomerular filtration rate, degree of autoregulation of both renal blood flow and glomerular filtration rate, and rates of excretion of electrolytes and water were all determined at perfusion pressures between 75 and 200 mm Hg. The results showed that angiotensin in reasonably low dosages can cause the normal dog kidney to retain water and salt, but from a quantitative point of view it remains doubtful whether or not enough angiotensin is formed in patients with unilateral kidney disease to produce a similar effect. Studies on the various parameters of kidney function gave an insight into the mechanism of water and salt retention during angiotensin infusion and also explained why angiotensin infusion sometimes causes diuresis rather than antidiuresis.

ISSN:1660-8151    

DOI:10.1159/000179902

出版商:S. Karger AG    

年代:1971

数据来源: Karger

摘要:

The local thermodilution method was adapted for the measurement of renal venous outflow in man. The flow in model experiments varied in the range of 3% from the mean. Clinical measurement on one or successively on both sides was carried out in 35 patients with essential hypertension or proteinuria. In 3 subjects with healthy kidneys the average venous outflow from one kidney was 782 ± 112 ml/min. The average standard deviation of the difference between both kidneys in 7 bilaterally investigated persons was 51 ml/min. The variability of resting flow depended principally on respiration and amounted to 12 to 18%. Comparison of the results of the thermodilution measurement with the PAH-clearance and with the dye dilution technique gave a good correlation and confirmed the usefulness of the thermodilution method for the measurement of the renal blood flow

ISSN:1660-8151    

DOI:10.1159/000179903

出版商:S. Karger AG    

年代:1971

数据来源: Karger

摘要:

The inert gas washout technique of Thorburn et al. has been adapted to the rat. The left kidney was exposed and placed in a micropuncture type lead spoon. A lead ring, a fenestrated lead lid and a suitable collimator absorbed all radioactivity coming from outside the left kidney. Injections of 133xenon were made through a polyethylene aortic catheter. The washout of the radioactive indicator gas was monitored with a 2-inch crystal detector placed above the exposed kidney. By means of 85krypton autoradiography the 4 single exponential components of the washout curve of the normal rat kidney were identified with 4 vascular zones of the kidney: the cortex + subcortical area (CP I), the outer medulla (CP II), the inner medulla (CP III) and the hilar fat (CP IV). The following normal values were found for the intrarenal distribution of blood flow (IDBF) and for the local blood flow rates (Fi): 81.7% of total renal blood flow are supplied to CP I, 11.6% to CP II, 3.8% to CP II and 2.7% to CP IV. Local blood flow rates (in ml/min, g of tissue) were 5.21 in CP I, 0.79 in CP II, 0.09 in CP III and 0.13 in CP IV. As compared with other species no significant differences occur in IDBF nor local blood flow rates.

ISSN:1660-8151    

DOI:10.1159/000179904

出版商:S. Karger AG    

年代:1971

数据来源: Karger

摘要:

The relationship between changes in GFR and sodium and water reabsorption by the proximal tubule was studied in 11 control dogs and 8 dogs with salt retention produced by 5 days of DOCA administration. Fractional reabsorption by the proximal tubule was determined by recollection micropuncture before and after aortic constriction. Constriction produced significant and similar decreases in renal perfusion pressure, GFR, and RPF in control dogs and dogs with salt retention. Fractional reabsorption by the proximal tubule was significantly increased following constriction in control dogs but not in dogs with salt retention. The difference between the two groups was significant, P < 0.001. Plasma renin activity was significantly lower in dogs with salt retention before and after constriction, however, the percent increase in plasma renin activity after constriction was not different between the two groups. It is concluded that changes in GFR are accompanied by proportionate changes in reabsorption by the proximal tubule in dogs with salt retention.

ISSN:1660-8151    

DOI:10.1159/000179905

出版商:S. Karger AG    

年代:1971

数据来源: Karger

摘要:

In keeping with the programs of periodic hemodialyses and renal transplants, 40 saphenous vein autografts have been performed according to a surgical procedure, which consists of a subcutaneous implantation of a ‘U’ shaped segment obtained from the great saphenous vein of the same patient, anastomosed to an artery and a vein in the forearm or thigh to facilitate the puncture for hemodialysis. We describe an original surgical technique and we evaluate the cardiovascular implications of these flstulae. The following studies were performed before the venous grafting was done: electrocardiogram, vectocardiogram, cardiac X-ray series, arterial pressures, cardiac output, blood volume determination, central venous pressure, and comparative plethysmography. After the surgical procedure, the same studies were repeated supplemented by fistular flow, and angiography, at intervals which varied from 10 to 310 days post-fistula. The postsurgical studies revealed no noteworthy changes of concern, though with an adequate flow to perform dialyses and satisfactory integrity of the venous by-pass. In our series, the magnitude of the hemodynamic changes was not sufficiently severe as to contraindicate the procedure and we concluded that the venous autograft by itself does not harm the patient, rather embodies a valuable help in carrying out the hemodialyses for as long as it is necess

ISSN:1660-8151    

DOI:10.1159/000179906

出版商:S. Karger AG    

年代:1971

数据来源: Karger

摘要:

18 patients with biopsy proven chronic proliferative glomerulonephritis have been studied, 10 of the 18 received daily subcutaneous injections of depo-heparin until death or for a period of at least 1 year. 8 of the 10 patients so treated demonstrated significant improvement in renal function as measured by serial determination of endogenous creatinine clearance, Addis count, protein permeability index, and renal biopsy. 1 patient with severely impaired function prior to heparin therapy did not improve, but renal function remained stable during the period of treatment. 8 of the 10 control patients were followed adequately for evaluation. Of these 8, 6 demonstrated progressive diminution of renal function, 4 expired in renal failure; in addition, 1 control patient followed too sporadically to include in the study is known to have died of renal failure.

ISSN:1660-8151    

DOI:10.1159/000179907

出版商:S. Karger AG    

年代:1971

数据来源: Karger

摘要:

Erythrocyte and plasma potassium, magnesium, sodium and calcium were estimated before and after dialysis in 32 studies on 14 patients undergoing recurrent haemodialysis. Predialysis erythrocyte magnesium was raised while sodium and calcium were depressed. Erythrocyte potassium varied depending on the total body potassium status of the patient. During dialysis erythrocyte potassium and magnesium fell but sodium and calcium increased. Changes in erythrocyte water or blood pH did not account for the shift of erythrocyte cations during dialysis. With recurrent dialysis changes in erythrocyte cations reflected the cumulative effect of individual dialysis and were towards a normal erythrocyte electrolyte composition. Erythrocyte magnesium resisted depletion despite low serum levels. Low dialysate magnesium levels (0.3–0.5 mg/100 ml) are required to maintain near normal serum and cellular magnesium concentration

ISSN:1660-8151    

DOI:10.1159/000179908

出版商:S. Karger AG    

年代:1971

数据来源: Karger

ISSN:1660-8151    

DOI:10.1159/000179909

出版商:S. Karger AG    

年代:1971

数据来源: Karger

ISSN:1660-8151    

DOI:10.1159/000179910

出版商:S. Karger AG    

年代:1971

数据来源: Karger

摘要:

To examine the medullary washout theory of pressure diuresis, anesthetized diabetes insipidus dogs were subjected to variations in renal arterial pressure in acute experiments. Changes in arterial pressure within the range of renal blood flow autoregulation caused significant and proportionately greater increases in urine flow. There was a significant relationship between arterial pressure and GFR although autoregulation was observed. A significant relationship also existed between the changes in GFR and the changes in urine flow such that the urine flow changes could be accounted for by the GFR changes. The changes in urine osmolality exhibited a negative regression on arterial pressure, but were quantitatively very minimal. The results demonstrate that the pressure diuresis phenomenon can occur from factors other than medullary washout.

ISSN:1660-8151    

DOI:10.1159/000179911

出版商:S. Karger AG    

年代:1971

数据来源: Karger