Acute haemodynamic responses to unilateral renal artery stenosis in conscious dogs.

The acute responses to renal artery stenosis were studied in chronically instrumented, unanaesthetized dogs. Stenosis of one renal artery produced a rise in arterial pressure and a fall in total peripheral conductance, but no change in cardiac output. The resistance to blood flow of the stenotic kidney 1 h after stenosis was 25% greater than before stenosis. This rise in resistance was due to the resistance of the renal artery stenosis itself. Blood flow to the contralateral kidney fell by 13% (s.e.m. = 3) at 1 h and resistance rose by 39% (s.e.m. = 5). Plasma renin activity was elevated approximately 10 fold. Calculations of changes in peripheral conductances following stenosis showed that the stenotic kidney was responsible for 14% of the fall in total peripheral conductance at 1 h, and the contralateral kidney for 18%. Thus acute renal artery stenosis produced a prompt rise in arterial pressure due to reduced peripheral conductance, of which the two kidneys (stenotic and contralateral) were responsible for one-third.