Fig. 1.
Fatty acid elongase and desaturase expression in rat, mouse, and human liver. A: Livers from male Sprague-Dawley (SD) rats (2–3 months of age), C57BL/6 mice (2–4 months of age), and female humans (44–54 years of age) were used for RNA extraction and measurement of elongase and desaturase expression as described in Materials and Methods. Rats and mice were maintained on chow (Teklad) diets ad libitum. Human livers were obtained from the National Disease Research Interchange. mRNA abundance for each elongase and desaturase was measured by quantitative real-time (qRT) PCR. Results are expressed relative to an internal standard, β-actin (transcript/actin) (means ± SD; n = 4 for rat and mouse liver, n = 3 for human liver). B: Rat, mouse, and human liver was extracted for microsomes to assay elongase activity using three separate substrates, 16:0-CoA, 20:4-CoA, and 24:0-CoA. Results are expressed as elongase activity (nmol [14C]malonyl-CoA assimilated into fatty acids/mg protein) (means ± SD; n = 4 for rat and mouse liver, n = 3 for human liver). Δ5D, Δ5 desaturase; Elovl-1, fatty acid elongase-1. * P ≤ 0.05 versus rat liver by ANOVA.