Catecholamine responses to orthostatic stimulation in anephric man

Abstract

Acute experiments on nephrectomized animals suggest inhibition of adrenergic reflexes in the absence of renal humoral factors. That renal failure patients rendered anephric for control of hypertension also have difficulty with blood pressure regulation is confirmed by the blood pressure instability and hemodialysis shock in anephric patients. In the present study, anephric patients were stimulated by passive orthostatic tilting to the 75°, head-up position. Elevated plasma arterial and venous epinephrine and norepinephrine contents were found at rest and after tilting. The relative increase in circulating catecholamines after tilting is consistent with previous studies in normal patients. The resting elevation of catecholamines in these anephric patients suggests either loss of a renal factor restraining adrenergic activity or a chronic stimulus to sympathetic discharge such as hypovolemia.