Fig. 6.

Prostaglandin E₁ (PGE₁) potentiates the reflex effect of bradykinin. A continuous tracing of the blood pressure of a dog is shown arranged in three panels. In the upper one, the hypertensive responses to 2·0, 1·0 and 0·5 μg of bradykinin are shown; in the second tracing the same injections are repeated during infusion of prostaglandin E₁ (200 ng/minute). After the infusion (third tracing) the pressor effects of 0·5 μg of bradykinin gradually declined towards pre-treatment levels. Time 1 min; vertical scales mmHg.