Fig. 5.

HS-EGFRKO mice have paradoxically lower plasma levels of EGF. A: we monitored mid-light phase plasma EGF levels in HS-EGFRKO and wild-type mice at different ages and observed that the relative amount of EGF in the wild-type mice increased relative to HS-EGFRKO mice. There was twice as much circulating EGF in the wild-type mice compared with knockout (KO) mice at 12 and 44 wk of age. B: we measured mid-light phase plasma EGF in fasted mice and observed that in contrast to insulin, which decreased markedly (data not shown) the EGF levels remained constant and were always less in the HS-EGFRKO mice compared with the wild-type counterparts. *P < 0.02.