Autoregulation of cerebral blood flow during early experimental renal hypertension in the conscious dog

Using the radioactive microsphere technique, cerebral blood flow (CBF) was measured in six conscious dogs before intervention and again on the 3rd-5th days after inducing hypertension by the one-kidney Goldblatt (1-KGH) procedure. Sham-operated controls were also studied. The normal temporal variability of CBF, as well as the precision of the microsphere technique in measuring CBF were also determined in other normal dogs. A left atrial catheter was used for the microsphere injections (15 μm diam spheres) and an aortic catheter was used for cardiac output and blood pressure measurements. On the 3rd-5th days after 1-KGH, mean aortic pressure increased from a control value of 94 ± 7 mmHg to 135 ± 20 mmHg (P < 0.005). CBF did not change significantly from the control flow of 57.1 ± 7.9 ml/100 g per min. Calculated cerebral vascular resistance increased by 47% (P < 0.025) above the control value. Hence, the early phase of experimental renal hypertension is associated with adequate autoregulation of cerebral blood flow.