The effect of abdominal pressure on plasma antidiuretic hormone levels in the dog

Abdominal pressure (80 mm Hg) applied to 12 anesthetized dogs caused an elevation of plasma antidiuretic hormone (ADH) levels to more than twice the basal levels. This elevation of ADH levels was prevented by a prior infusion of dextran which in addition prevented the associated 20% fall in cardiac output. Since other hemodynamic events were unaffected by either the abdominal pressure or the dextran infusion, it is concluded that the effect of abdominal pressure on plasma ADH levels is probably caused by an alteration in cardiac output.