Figure 1

Respiratory quotient and liver fat content of WT, ICAM-1-, and CD18-deficient mice. A: Respiratory quotient was measured in male (top panel) and female (bottom panel) WT, ICAM-1-, and CD18-deficient mice in fed state and upon transition to fasting. ICAM-1- and CD18-deficient mice fail to make a prompt switch to fat oxidation during fasting compared with WT mice. Early after the onset of fasting, the difference in RQ between WT mice and either ICAM-1- or CD18-deficient mice is statistically significant (P < 0.05). After a few hours of fasting, the difference in RQ between WT mice and either ICAM-1- or CD18-deficient mice becomes even greater (P < 0.01). Each experimental group had 4 mice. Data were analyzed using ANOVA followed by Student PLSD (Protected Least Significance). Black bar indicates time periods when animals were in the dark. B: Frozen sections of livers from 24-h fasted male WT, ICAM-1-, and CD18-deficient mice were stained with Oil Red-O to visualize neutral lipids in the liver. Dark staining on the images represents lipid droplets that have retained the dye after destaining procedure. Representative sections are shown.