Bradykininの血管作用

―拡張の条件および機構について―

抄録

When an isolated rabbit-ear is perfused with its blood, the administration of bradykinin causes vasodilatation and increased outflow. This effect of bradykinin is entirely opposed to the results indicated in the perfusion with Ringers solution. The unkown vasoactive substances included in serum reverse the vascular action of bradykinin from constriction to dilatation. This phenomenon can be reproduced by means of adding the well known vasoconstrictive substance such as adrenaline to Ringers solution as perfusate. Since the venous system is always contracted with bradykinin, the arterial system must exceed the venous system in responce for bradykinin to show increased oufflow. When bradykinin causes the vasodilating action, blood celles may promote the rate of increase of oufflow probably through the loss of mechanical resistence to the vascular bed. The optimum pressure and pH of perfusate is also one of the conditions as to increased outflow with bradykinin.