Jan Ek

Studies on the renal circulation and renal function in mitral valvular disease. I. Effect of exercise.

In 31 patients with mitral stenosis of varying severity the effect of light, steady exercise during 15 to 17 minutes on renal function and renal circulation has been studied during heart catheterization. The results have been compared with the values obtained at rest in 72 patients with mitral stenosis. Exercise produced a decrease in clearance of para-aminohippurate and sodium excretion and an increase in renal resistance, changes not produced in normal individuals. Cardiac output and pulmonary pressures increased. In patients with right heart failure exercise produced increased pressures but no increase in cardiac output, and only slight changes in clearance but increase in renal resistance and renal venous pressure.

Studies on the Renal Circulation and the Renal Function in Mitral Valvular Disease III. Effect of Valvulotomy

Renal circulation and function were studied simultaneously with pulmonary and systemic hemodynamics in 25 patients with mitral stenosis before and six weeks after valvulotomy. Postoperatively no essential change in renal circulation or function could be demonstrated whether significant relief of pulmonary hypertension had occurred or not. However, results from follow up studies made on 21 patients up to more than three years after operation showed that renal plasma flow could be increased in patients that were hemodynamically improved at the postoperative study. The effect of exercise was investigated in eight patients before and after valvulotomy. In seven the response pattern of renal circulation and function was essentially unchanged regardless of whether improvement in pulmonary pressures and cardiac output did or did not occur. In the eighth patient, the only one with elevated right atrial pressure before operation, the response to exercise improved markedly. Preoperative results obtained on seven patients who died in connection with operation showed that a fatal outcome was not necessarily related to the degree of impairment in renal circulation or function.

Studies on the Renal Circulation and Renal Function in Mitral Valvular Disease II. Effect of Apresoline

In a study of the nature of the renal changes in patients with mitral stenosis, lowered renal function and reduced renal circulation the effect of Apresoline, given during heart catheterization to 12 patients with mitral stenosis of varying severity, was studied. The drug was found to increase renal blood flow (and decrease arterial blood pressure), showing that the renal changes in mitral stenosis are reversible. The two effects of Apresoline were shown to be independent of each other.

The effect of a single intravenous dose of scillaren B on the pulmonary circulation and renal function in patients with rheumatic heart disease.

Abstract 1. 1. The effect of a single intravenous dose of Scillaren B on the blood pressures in the lesser circulation, and the clearance values for inulin and para-aminohippurate as well as sodium excretion were studied in six patients with rheumatic heart disease. 2. 2. Heart rate rapidly decreased, in some cases during the first minute after administration. 3. 3. Pulmonary blood pressures fell rapidly, while cardiac output remained unchanged. Stroke index rose considerably. 4. 4. No effect on clearance values or sodium excretion was noticed. 5. 5. Compared with lanatoside C, Scillaren B acts with shorter latency on pulmonary pressures in patients with mitral stenosis, but does not show any of the prompt, direct renal effects of the digitalis drug. 6. 6. Scillaren B is a swift and potent cardiac drug. The renal action which has been described earlier is secondary to its effect on the heart.

The influence of a rapid infusion of glucose on renal dynamics and sodium excretion in patients with arterial hypertension: a preliminary report.

Abstract 1. 1. The renal clearances for inulin, endogenous creatinine, sodium paraaminohippurate and sodium excretion were determined in nine cases of arterial hypertension before and during a rapid infusion of 5 or 3 per cent glucose in water. 2. 2. The low basal clearances immediately increased to normal or near normal values in all cases when the rapid infusion was started. 3. 3. The excretion of sodium and water slowly increased during the experiment. The diuresis increased approximately to a rate about 50 per cent of the infusion rate. The sodium excretion increased up to several hundred per cent. There was a statistically significant negative correlation between the basal value for sodium excretion and the maximal value reached during the infusion. 4. 4. The glomerular filtration rate and sodium excretion varied independently of each other. 5. 5. In four cases where the blood pressure was followed during and after the study, it decreased markedly for several days.

The assessment of the tubular function of the kidneys

Publisher Summary This chapter presents the physiological background for the most important methods of estimating the tubular function in man. The tubular functions, which are most often assessed for clinical and physiological purposes, can be divided into four main groups. These includes the concentration and dilution of the glomerular filtrate, adjustment of the composition of the urine, conservation for the body of valuable solutes in the glomerular filtrate, and clearing of certain unnecessary or foreign substances from the body. The chapter reveals that the theories on which several of the tubular function tests are founded are valid only for the normal kidney. The processes of reabsorption and secretion of water and the different electrolytes are woven together in a complicated pattern. The net reabsorption of a filtered substance may be comparatively simple to determine from the calculated filtered amount minus total excretion in the urine, or vice versa for the amount excreted tubularly. . Most of the methods for assessment of the tubular handling of water and electrolytes fall into one of two main groups. One group involves the study of the influence of high physiological loads of water and electrolytes on the renal excretion and the effect on this excretion of depletion of the subject of water and electrolytes. The other group involves the study of the effect of administered hormones and of certain drugs supposed to influence the transporting mechanism in the tubular cells.