The effects of angiotensin II on Doppler signals from a soft-tissue tumour.

A 10 mHz continuous-wave Doppler system has been used to detect blood flow within a sarcoma implanted in a rabbit's ear. The effects of vasoconstriction produced by intravenous angiotensin II were studied. Criteria are described that enabled differentiation of the Doppler signals from the tumour from those of the adjacent central artery. The effect of vasoconstriction upon these criteria is also described.