Effect of Adrenaline, Noradrenaline, Angiotensin and Renal Nerve Stimulation on Intrarenal Distribution of Blood Flow in Dogs

The acute effect of adrenaline, noradrenaline. angiotensin and renal nerve stimulation on intrarenal blood flow was studied in 15 dogs. Local clearance of hydrogen gas measured polarographically with 2–4. needle-shaped platinum rlectrodes in the outer medulla served as indicator for medullary blood flow. Total renal blood flow was measured simultaneously with electromagnetic flowmeter. Adrenaline, noradrenaline and angiotensin infused i.v. or into the renal artery over a period of 5–15 min reduced outer medullary hydrogen clearance and total renal blood flow to 25–90 per cent of control, and on an average to the same extent. Renal nene stimulation produced the same pattern with flow reduction to 50–75 per cent of control. Since changes in total renal blood flow mainly reflect changes in cortical per-fusion. it is concluded that resistance to flow was increased proportionately in the cortical and juxtamedullary circulation. Considerable local xrariations in response of outer medullary hydrogen clearance observed with all stimuli suggested local differences in vasoconstrictor response, but no consistent difference between cortex and medulla.