Although the kidney strives to maintain its perfusion within tight

boundaries, considerable blood flow fluctuations do occur. The

reasons for this are the rather slow acting compensatory

mechanisms of renal blood flow autoregulation, the effects of

renal nerves, hormonal influences, etc. It seems that variations

in renal perfusion can exert a major influence on renal excretory

functions, on renin release and on blood pressure. The clinical

importance of renal blood flow variability is not fully understood.

In many situations, the absence of normal cardiovascular

oscillations seems to be a risk factor. Large fluctuations in

perfusion pressure to the kidney, however, in the long run, may

induce target organ damage.