ROLE OF ADENINE NUCLEOTIDES IN PERIPHERAL VASODILATING EFFECT OF THROMBIN

The experiments were designed to study the mediating mechanism for the previously demonstrated vasodilating effect of thrombin when small amounts are infused into the femoral artery of the dog. Washed blood cells, suspended in physiological saline, were incubated for a short time with small amounts of thrombin. The supernatant from such a cell suspension exerted a highly vasodilating effect when infused into the femoral artery. This vasodilating effect was compared to that of serotonin, histamine, adenosine and adenine nucleotides. Histamine, adenosine and adenine nucleotides caused the same type of reactions as that of vasoactive supernatants. By inactivation experiments, where these substances, as well as vasoactive super‐natants, were heated or incubated with plasma or ADP‐ase–ATP‐ase (Apyrase), it was concluded that the vasodilating agents in the latter are mainly ADP and to some extent ATP. © 1969 Scandinavian Physiological Society