Rats were treated with 1.0–2.0 × 1012 particles/ml of Ad-GPAT1 or Ad-EGFP virus for 5–7 days (Ad-EGFP, n = 9; Ad-GPAT1, n = 11). A, GPAT1 enzyme activity was determined in total liver membranes after inhibiting endoplasmic reticulum GPAT with NEM. Results are expressed as mean ± S.E. B, anti-FLAG Western blot of total membranes from primary hepatocytes infected with Ad-GPAT1 (Control), from liver of a rat infected with Ad-EGFP (EGFP), and from liver, gastrocnemius muscle (2 lanes), and heart (2 lanes) of rats infected with Ad-GPAT.