Figure 4.

Experimental traces showing the effects of inducing flow for 10 min periods at (A) 0.5 and 1.0 mL·min⁻¹ and (B) 2.5, 5.0 and 10 mL·min⁻¹ in carotid artery segments at an intermediate level of U46619-induced tone. Traces (A) and (B) were from different vessels. Low rates of flow induced a biphasic response, comprising an initial dilatation, followed by a more slowly developing constriction that was sustained until the termination of flow. Higher rates of flow induced mostly constriction. The 10 min periods of flow are indicated by the time bars. The numbers on the trace indicate the flow rate in mL·min⁻¹. The pressure traces (in mmHg) show that flow was induced while maintaining constant pressure.