Systemic Administration of Naked DNA: Gene Transfer to Skeletal Muscle

Transgene expression in hindlimb muscles pursuant to intravascular injection of naked DNA. Plasmid DNA (100 mg in 2 ml PBS) that encoded the luciferase gene as a reporter was rapidly (within 5 s) injected through either tail vein or tail artery, and the blood flow in the aorta and vena cava was blocked for 15 s (see inset). Transgene expression in the major muscle groups was determined by luciferase activity 48 h after injection (relative light units). Luciferase activity following intra-arterial injection was about tenfold higher than that following intravenous injection, perhaps reflecting deeper distribution of arteries within muscles.