ISOLATED LIMB PERFUSION WITH MELPHALAN FOR HUMAN-MELANOMA XENOGRAFTS IN THE HINDLIMB OF NUDE RATS - A SURVIVING ANIMAL-MODEL

We have established a surviving model of isolated limb perfusion using xenografts of the human melanoma cell line MM 96L injected subcutaneo usly into the hindlimb of a nude rat, The femoral artery and vein were cannulated via the left renal artery and vein and the hind limb was i solated using tourniquets. The limb was perfused with Krebs Heinseleit buffer at 37 degrees C containing 4.7% bovine serum albumin at a cons tant flow rate of 4 mi per min for 30-60 min with 100% survival of the animals, Tumour vascularization and blood flow were demonstrated usin g vascular casts and [Cr-51]-microspheres. Following the addition of m elphalan (15 or 100 mu g/ml), drug concentrations in the perfusate, ti ssues and systemic circulation were determined using high pressure liq uid chromatography (HPLC), Systemic leakage, assessed using [I-125]alb umin and melphalan and detected by a gamma-counter and HPLC respective ly, was <0.5%. The melphalan concentration and tissue flow rate in the tumour deposits were 40 and 30% respectively, when compared with the surrounding subcutaneous tissue, At a dose of 15 mu g/ml, melphalan ca used a reduction in tumour growth after 60 min perfusion, and a signif icant reduction in tumour size was seen when the melphalan dose was 10 0 mu g/ml. The surviving nude rat model of isolated limb perfusion for recurrent melanoma will allow examination of optimal perfusion condit ions, along with the pharmacokinetics, pharmacodynamics and efficacy o f melphalan and other drugs.