Left atrial distension and intrarenal blood flow distribution in conscious dogs.

Measurements were made with radioactive microspheres of the distribution of renal blood flow in conscious dogs during left atrial distension. Urine volume, sodium excretion, mean arterial blood pressure and heart rate increased during the 60 min period of left atrial distension (increase in left atrial pressure by about 1.0 kPa). Total renal blood flow and cardiac output (electromagnetic flowmeters) did not change. The perfusion rates of four renal zones did not change. Striated muscle blood flow (M. psoas) fell markedly.--Stimulation of left atrial receptors in conscious dogs is followed by an increase in renal and skeletal muscle resistance. The diuresis and natriuresis during left atrial distension is not accompanied by a detectable redistribution of renal cortical blood flow.