THE MECHANISM OF PROLONGED FLUORESCEIN CIRCULATION TIME IN EXPERIMENTAL TRAUMATIC SHOCK

Abstract
The fluorescein circulation time in normal dogs suffering fatal muscle trauma is progressively prolonged. Simultaneously detd. cyanide circulation times do not show corresponding increases but instead show plateaus at increased levels. In dogs with bilateral upper thoracic sympathectomies the fluorescein circulation time following trauma behaves as does the cyanide circulation time in the normal traumatized animal. These facts indicate that the mechanism of prolongation of the fluorescein circulation time in the normal dog in traumatic shock is associated with an increased activity of the sympathetic nervous system particularly upon the peripheral portion of the vascular tree. The fact that neither the fluorescein nor the cyanide circulation times are. as greatly prolonged following fatal hemorrhage as following fatal muscle trauma with a comparable blood volume reduction indicates that the sympathetic nervous system is not nearly so active throughout the course following hemorrhage as it is following muscle trauma.