Figure 2:

Representative blood pressure and cerebral blood flow response to serial blood withdrawals for control animals on a low salt diet (A) and a short-term (3 day) high salt diet (B). Each measurement is averaged using a moving window to see the trends in response of pressure and flow. In addition, during each of the blood withdrawals the pressure catheter was disconnected to allow blood to be withdrawn, so the periods during the actual blood withdrawal have been removed from the time course. Note that flow and pressure for the control animal (LS diet) does not change much over the first three blood withdrawals compared with changes observed in the short-term high salt animal. In addition, the control animal showed only ~ 25% drop in flow compared to ~ 75% drop in the short-term high salt animal over the course of the experiment. The shorter duration of the experimental period in the HS-fed rat vs. the LS-fed control reflects the reduced ability of the HS animal to compensate for the reduction in blood pressure following blood volume withdrawal.