DIETARY LEVEL OF MAIZE OIL AFFECTS GROWTH AND LIPID-COMPOSITION OF WALKER-256 CARCINOSARCOMA

Walker 256 carcinosarcoma cells (1 x 10(4)) were injected into the rig ht thigh muscle of Sprague-Dawley rats (125 g) consuming isoenergetic (200 g fat/kg) diets containing 20, 100 and 200 g maize oil/kg and 180 , 100 or 0 g hydrogenated lard/kg respectively. Ten rats from each die tary regimen were killed every 4th day. Tumours grew rapidly from day 0 to day 8 post-transplant regardless of dietary regimen. However, aft er 8 d more tumours regressed and there were fewer deaths in animals f ed on 200 g maize oil/kg compared with animals fed on 20 or 100 g maiz e oil/kg. Linoleic acid (LA) levels were higher in phospholipids (PL) of growing tumours than in regressing tumours whereas arachidonic acid levels in PL were lower in growing tumours indicating a possible alte ration in the desaturation and elongation of LA. Serum prostaglandin E (2) levels were slightly lower in rats with regressing tumours than in rats with growing tumours.