Renal tubular sensitivity to atrial natriuretic factor in essential hypertension.

Objective: To study the tubular site or sites of the natriuretic action of atrial natriuretic factor and the possible differences between healthy subjects and patients with essential hypertension.

Design: Nine healthy volunteers and six patients with essential hypertension were studied on four test days under standard conditions, water loading and hydropenia with mannitol or saline loading. On each test day baseline, atrial natriuretic factor infusion (1 microgram/min) and recovery measurements were performed after equilibrium had been reached.

Differences in erythrocyte sodium transport between human plasma and artificial medium: the role and character of sodium efflux and influx stimulating plasma factors.

The main objective of this study was to further characterize the plasma factor(s) which stimulate sodium efflux from erythrocytes, which we reported previously. Dialysis of plasma against an artificial medium using membranes with varying molecular mass cut-off points revealed relative molecular mass(es) of the factor(s) of 100-1000 Da. The factor(s) could be absorbed on Dowex at pH 1.

Atrial natriuretic factor influences renal diurnal rhythm in essential hypertension.

We investigated in six patients with essential hypertension the effect of a low dose atrial natriuretic factor infusion for 5 days on the diurnal rhythm of renal electrolyte excretion. Atrial natriuretic factor infusion increased the net excretion of sodium and caused a delay in its time of maximal diurnal urinary excretion. Similarly, atrial natriuretic factor caused an increase in the net excretion of chloride, calcium, and magnesium and also changed the diurnal rhythms of these electrolytes.

Explantation of mesangial cell 'hillocks': a method for obtaining human mesangial cells in culture.

A simple method is presented for selective cell culture of human mesangial cells using explantation of mesangial cell hillocks. Glomeruli which had been incubated with collagenase were explanted on plastic tissue culture flasks. Three to 6 weeks after explantation, a rapidly growing multilayer of elongated mesangial cells was observed to grow over the previously established monolayer of glomerular epithelial cells, ultimately forming multiple nodular foci of mesangial cells or 'mesangial cell hillocks'.

Changes in renal function induced by ACE-inhibition in the conscious two-kidney, one-clip Goldblatt hypertensive dog.

In order to study why the diagnostic sensitivity of 123I-hippurate renography for a renal artery stenosis is improved by angiotensin converting enzyme (ACE-) inhibition we used the model of the conscious chronically instrumented two-kidney, one-clip Goldblatt hypertensive dog. Urine flow (UV), renal blood flow (RBF), glomerular filtration rate (GFR) and effective renal plasma flow (ERPF) were measured (with constant infusion of 125I-iothalamate and 131I-hippurate, respectively) for both kidneys separately before and after a bolus injection of a mild unilateral renal artery stenosis (approximately 30% reduction of RBF). During ACE-inhibition, there were remarkable falls in poststenotic GFR (from 37 +/- 5 to 4 +/- 2 ml/min, p less than 0.