Properdin Titers of Dogs Surviving Hemorrhagic Hypotension.

Abstract
Fifteen dogs were bled to mean arterial pressure of 35 mm Hg for 135 min., after which shed blood was reinfused. Seven animals survived longer than 72 hours. Serum properdin levels fell in all dogs during post-transfusion phase but titers of non-survivors were significantly more depressed than those of survivors. In survivors, properdin levels rose during next few days and reached a level considerably above control by 4th-8th day, then started to decline toward control. Dogs subjected to more severe conditions of hypotensive shock but perfused by way of superior mesenteric artery showed a similar pattern.