Insulin-induced phosphorylation of PKB and IR-β expression in liver. Chow, HFP, HFL and HFPS fed mice were subjected to continuous PBS or insulin (0.25 mU/min) i.v. infusion for 15 min before organ collection. Extracts from livers were immunoblotted with anti-phospho-Ser 473 (A) and anti-IRβ antibodies (B). Total PKB and α-actin were used as loading controls, respectively. The results of densitometric quantification are expressed in arbitrary units as the ratio over the chow group and are means ± SEM, n = 7-8. *,$ p < 0.05 compared with PBS and chow, respectively.