Bradykinin: Vascular Relaxant, Cardiac Stimulant

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Science  06 Sep 1963:
Vol. 141, Issue 3584, pp. 907-908
DOI: 10.1126/science.141.3584.907


Bradykinin infusion causes an increase in cardiac output in rats whether the autonomic nervous system is blocked or not. After autonomic blockade, bradykinin causes a lesser decrease in the total peripheral resistance but a greater increase in cardiac output, resulting in an elevation of arterial pressure. The increase in cardiac output is caused by a small increase in heart rate and a substantial increase in stroke volume. The fact that these increases are observed after autonomic blockade suggests that bradykinin increases cardiac output by direct stimulation of the heart.