Release of 5-hydroxytryptamine and adenosinetriphosphate in extracorporeal circulatory systems as a result of corpuscular blood trauma

¹ Department of Histology and Physiology, Zoological Institute, and Institute of Physiology, University of Helsinki; and the Wihuri Research Institute, Helsinki, Finland

Model experiments in rabbits and dogs with a simple extracorporeal circuit yielded suggestive evidence that 5-hydroxytryptamine (5-HT, serotonin) and adenosinetriphosphate (ATP) are released into plasma as a result of corpuscular blood trauma. Concurrently the urinary excretion of 5-HT was markedly increased, while that of 5-hydroxyindoleacetic acid (5-HIAA), the main excretory product of 5-HT, showed the opposite trend. In view of the potent vasoactive, cardiopulmonary and allied effects of ATP and 5-HT the findings are applicable as explanations for some features associated with perfusion experiments in general. They may also serve as a guide for disentangling the mechanisms of some complications including the fatalities following the use of heart-lung machines for open cardiac surgery.