Effects of selective COX1 versus COX2 inhibition on cortical and medullary blood flow. (a and b) The effect of acute infusion of the COX1 inhibitor (triangles, n = 5) or COX2 inhibitor (squares, n = 4) on CBF and MBF in normal mice. *P < 0.05 vs. base-line MBF at 10 minutes; ^#P < 0.05 vs. MBF in the COX1 inhibitor–infused mice. (c and d) The effect of continuous Ang II infusion on CBF and MBF in mice pretreated with the COX2 inhibitor (squares, n = 7), COX1 inhibitor (triangles, n = 8), or vehicle (control group, circles, n = 5). *P < 0.05 vs. base-line MAP at 10 minutes; ^#P < 0.05 vs. control or COX1 inhibitor–treated mice. (e and f) The effects of Ang II infusion on CBF and MBF in COX2 knockout (squares, n = 6) and COX1 knockout mice (triangles, n = 6). *P < 0.05 vs. base-line MAP at 10 minutes; ^#P < 0.05 vs. COX1 knockout mice.