INFLUENCE OF LOWER BODY NEGATIVE PRESSURE UPON ARGININE VASOPRESSIN RELEASE

Abstract

Lower body negative pressure (9-12 kPa [pascal]) was applied to 10 normal subjects. Large increases in plasma arginine vasopressin concentration occurred only in subjects that experienced syncopal symptoms and developed hypotension. Blood samples obtained from the superior vena cava at 1/2 min intervals during application of negative pressure showed that maximal plasma vasopressin concentrations occurred with hypotension. Chromatography of the presyncopal plasma on Sephadex G-25 gave a large peak which eluted in the position of synthetic arginine vasopressin.