A, VEGF165 (▴) and VEGF165b (□) increase Lp in frog microvessels in a concentration-dependent manner. B, the data from A normalized to the maximum and minimum responses. The dashed lines indicate the EC50 (VEGF165: EC50, 1.6 × 10−11; VEGF165b: EC50, 6.5 × 10−13, P < 0.05, F-test.) Data are expressed as means ± s.e.m.