The isolated organs of horse serum sensitized dogs, perfused with Locke's solution containing 0.04 to 2.5 per cent horse serum, give the following reactions:
Lungs: Slight preliminary vasodilation, followed by a pronounced vasoconstriction. Marked edema.
Intestines: Distinct vasoconstriction. Marked edema.
Liver: Slight vasoconstriction. Slight edema.
Hind Quarters: Either: (1) slight vasodilation without edema or (2) slight vasoconstriction with marked edema.
The vasoconstriction in these organs may possibly be secondary to increased tissue pressure from edema. If so, increased specific capillary permeability must be looked upon as the dominant underlying physiological factor in these reactions.