EGF increased serum P. (A) P in sham rats and in EGF (500 ng)-treated rats. (B) P 0, 4, 8, and 12 h after treatment with vehicle (sham) or EGF (500 ng). Results represent mean ± SEM (n = 12). a, P < 0.01 vs. d22 sham; b, P < 0.01 vs. d22 sham and d23; c, P < 0.001 vs. the rest; ***, P < 0.001 sham vs. EGF-treated rats.