Does magnesium play a role in the hypokalemia of Bartter's syndrome?

A patient with Bartter's syndrome manifested hypomagnesemia in addition to hypokalemia. Under conditions of maximal free water production, he had a fractional distal solute reabsorption of 0.65, a value consistent with a renal defect in sodium chloride reabsorption in the thick ascending limb of the loop of Henle.

Renal tubular reabsorption of chloride in Bartter's syndrome and other conditions with hypokalemia.

Fractional distal chloride reabsorption was measured in 8 patients with Bartter's syndrome, 8 patients with comparable degrees of hypokalemia of different etiologies and 7 normal subjects during maximal diuresis induced by an intravenous infusion of 5% dextrose in water. A low fractional distal chloride reabsorption (0.55 +/- 0.

The effects of oral furosemide on the response of urinary excretion of cyclic adenosine monophosphate and phosphate to parathyroid extract in normal subjects.

We studied the effects of oral furosemide, 80 mg/day for 7 days, on the response of urinary excretion of phosphate and cyclic AMP to exogenous parathyroid extract (PTE) in 6 normal subjects. All 6 subjects had marked increases in urinary calcium and a significant increase in urinary cyclic AMP from the control to the furosemide periods: this suggests that furosemide-induced hypercalciuria produced elevated parathyroid activity. After treatment with furosemide, the response of urinary cyclic AMP and phosphate to PTE was blunted.

The effect of vasopressin in water-loaded hypokalemic patients is prostaglandin-independent.

Potassium-depleted subjects regularly excrete dilute urine with a high free-water clearance which cannot be suppressed either by solute loading or by water deprivation. In man, as in the dog and rat, potassium depletion impairs the ability of the kidney to achieve maximal urinary solute concentration and vasopressin is unsuccessful in overcoming this defect. In man and in the dog, potassium depletion induces a rise in urinary prostaglandin E2, an effect which can be reversed with indomethacin, a cyclo-oxygenase inhibitor.

Nephropathologic characteristics of a woman with Bartter's syndrome after prolonged treatment with spironolactone.

A study was made of two renal biopsy specimens obtained from a 22-year-old woman with Bartter's syndrome, the first to substantiate the diagnosis, the second 2 years later after the treatment with spironolactone. The first renal biopsy revealed remarkable hyperplasia and hypertrophy of the juxtaglomerular apparatus. The numerous proliferating cells were characterized by abundant lysosomal granules and dilated endoplasmic reticulum.

Schedule shifts, life quality and quantity--modeled by murine blood pressure elevation and arthropod life span.

During the span from 50 to 100 days and beyond, the male stroke-prone Okamoto rat develops systolic blood pressure measures in excess of 200 mm Hg. In the course of developing such a marked elevation in systolic blood pressure mean, this intermittently handled male Okamoto rat exhibits a statistically significant circadian rhythm with large amplitude. This amplitude may represent, at least in part, a response to intermittent handling; it is several times larger than the amplitude for spontaneously mesor-hypertensive (but not stroke-prone) female animals of the same age.

Chronobiology of blood pressure.

Blood pressure in normal and hypertensive subjects shows circadian variability with the minima during the hours of sleep. The factors influencing blood pressure show circadian variability, in particular, plasma and urinary aldosterone, plasma deoxycorticosterone and urinary sodium (factors implicated in cardiac output), angiotensin II as measured by plasma renin activity, plasma and urinary epinephrine and norepinephrine, and plasma and urinary prostaglandins of the E series (factors implicated in peripheral resistance). Direct causal relationships have not been established.

The effect of high-sodium and low-sodium intakes on blood pressure and other related variables in human subjects with idiopathic hypertension.

Nineteen patients with hypertension in whom all known causes of blood pressure elevation had been ruled out were classified as "salt-sensitive" or "nonsalt-sensitive" from the changes in blood pressure with changes in sodium intake from 9 meq to 249 meq/day. With the diet containing 249 meq sodium per day, there were no statistically significant differences in plasma sodium, potassium, chloride, aldosterone, cortisol or renin activity, or in urinary potassium, aldosterone or 17-hydroxycorticosteroids between the two groups. The "salt-sensitive" patients retained more sodium on the high-sodium diet than did the patients who were not sensitive to salt ("nonsalt-sensitive"); accordingly, sodium induced more weight gain in the salt-sensitive patients.

Control of calcium absorption: effect of sodium chloride loading and depletion.

In six out of eight patients with normal parathyroid function and in two subjects with hypoparathyroidism, sodium chloride loading was shown to increase calcium absorption as measured by the 47Ca absorption test. Although no significant change was seen in the renal and fecal excretion of calcium, a slight decrease in total serum calcium did occur with increased sodium intake. The change in calcium absorption was not accompanied by a detectable change in calcium balance.

Chronobiology in the diagnosis and treatment of mesor-hypertension.

An elevation of systolic and diastolic bloodpressure to values regarded as abnormal ones on the basis of conventional criteria was recognized by self-measurement. For both systolic and diastolic blood pressure, the overall means adjusted for rhythms, the so-called mesors, also were elevated in the light of their response to treatment: these mesors were found to be lowered with statistical significance when values during treatment were compared by an objective test with values measured before treatment. Individualized rhythmometry quantitatively characterizes a predictalbe portion of the variability in human blood pressure and tests for the statistical significance of changes in blood pressure as a function of the treatment and also as a function of the circadian timing of such treatment.

Increase in renin release after sionaortic denervation and cervical vagotomy.

The role of the vagi in the control of renin secretion was investigated in dogs maintained on a high-salt diet. Renal perfusion pressure was maintained relatively constant by the manipulation of a suprarenal aortic snare. Mean arterial blood pressure (MAP), plasma renin activity (PRA), and packed cell volume (PCV) increased after sinoaortic denervation and cervical vagotomy.

Ewing's sarcoma as a cause of the syndrome of inappropriate secretion of antidiuretic hormone.

A patient with Ewing's sarcoma presented with the syndrome of inappropriate secretion of antidiuretic hormone (SIADH) (1). Plasma values for vasopressin were found to be over four times the normal values expected for the plasma osmolality. At postmortem examination, the arginine vasopressin concentration in the tumor tissue was ten times that of the plasma.