Increased aldosterone secretion following acute constriction of the inferior vena cava.

Aldosterone secretion (1) and aldosterone excretion in urine (2) are markedly elevated in dogs with chronic right heart failure and in dogs with chronic ascites secondary to thoracic caval constriction. It was suggested that the adrenal cortex is stimulated to secrete aldosterone by factors resulting from a high venous pressure and the consequent loss of fluid and electrolytes from the blood stream. The precise nature of these factors remains to be defined. The purpose of the present study was threefold: 1) to determine the effects of acute caval constriction on aldosterone secretion in an attempt to develop an acute experimental preparation for evaluation of factors influencing aldosterone secretion; 2) to evaluate the effect of changes in vascular volume on aldosterone output; and 3) to apply a radioisotope derivative technique developed by two of us (B. K. and R. E. P.) for the determination of aldosterone and corticosterone in 2 ml. samples of adrenal vein plasma.