Long-term retention of a novel antioxidant sulphur-substituted fatty acid analogue after local delivery in porcine coronary arteries

Objective: Antioxidants have been suggested to reduce restenosis after ball oon angioplasty. A novel sulphur-containing fatty acid, tetradecylthioaceti c acid (TTA), with antioxidant properties, is efficiently incorporated into cellular phospholipids. We have determined the uptake and retention of TTA after local coronary artery delivery in 20 pigs. Design: Radiolabelled TTA was delivered to 40 main coronary arteries via a multiporous coronary angioplasty balloon catheter inflated before, after, o r without overstretch vessel injury. The animals were killed at intervals o f up to 6 weeks post-procedure. The radioactivity of the tissue sections wa s determined as nmol TTA/g tissue. Results: Concentrations of TTA in the coronary arteries were 1.84 +/- 0.45 nmol/g up to 24 h, 1.50 +/- 0.96 nmol/g at 2 weeks, 0.22 +/- 0.11 nmol/g at 4 weeks and a trace was present at 6 weeks (p-value for trend <0.01). The arterial wall uptake at the delivery site was higher than distal to deliver y (1.84 +/- 0.37 vs 0.55 +/- 0.13 nmol/g, p = 0.006) and perivascular fat ( p < 0.01) but not higher than in the myocardium. Infusion before, after or without vessel injury was not important for tissue concentration. Conclusions: After local coronary artery delivery, the antioxidant TTA is t aken up by the arterial wall in which it is retained for at least 4 weeks.