RES function and tumour take and tumour growth in the liver and in the kidney—An experimental study in rats

This experimental study in rats examines tumour take and growth after RES modulation in an organ rich in macrophages—the liver—vs. an organ poor in macrophages—the kidney. A control group of 16 rats had 1.0 × 10 6 transplantable adenocarcinoma cells inoculated in the liver and the same number in the left kidney. They were compared with a RE-stimulated group of 16 rats treated i.v. with Zymosan ( 3 mg/100 g for 3 days) and a RE-depressed group of 16 rats treated with i.v. methylpalmitate ( 100 mg/100 g for 3 days) before tumour inoculation. Tumour size was measured on days 7 and 14. The animals were killed on day 14. Mortality was significantly higher in methylpalmitate-treated rats than in control groups. Tumour take in the kidney was not affected by RES stimulation or depression. In the liver, RES stimulation caused significantly less tumour take. Depression of RES with methylpalmitate did not increase tumour take or tumour growth in the liver, which was very high in the control group.