Figure 2. Effect of acute ethanol on hepatic DAG levels.
Positive electron spray ionization mass spectrums are shown from liver extracts after chromatographic separation on a silica gel column to remove polar phospholipids. 1.48 μg phosphate of sample was loaded per column. Since Na+ adducts were used to detect DAG species, the m/z value represents the molecular weight of the respective DAG plus the weight of a sodium molecule (M+Na+). Representative chromatograms of livers from control and ethanol-exposed mice are shown with peaks identified by fragmentation to be a known DAG: DAG 32:1 with an ether linkage (M+Na+=575), DAG 32:0 with an ether linkage (M+Na+=577), DAG 32:1 (M+Na+=589), DAG 34:2 (M+Na+=615), DAG 34:1 (M+Na+=617), DAG 36:4 (M+Na+=639) and DAG 38:6 (M+Na+=663). The series numbers indicate the total number of carbons in the acyl chains on the DAG molecule. The peak at m/z 535 corresponds to the internal standard (DAG 28:0).