Mitogenic effect of syngeneic peritoneal fluids and their relation to lymphocyte trapping

Syngeneic peritoneal fluids, i.e. tumor ascitic fluid (TAF); peritoneal exudate fluid (PEF) or normal peritoneal washouts, induce a mitogenic effect in the spleens and lymph nodes of syngeneic animals. Fractions of TAF and PEF of MW less than 1,000 are also effective mitogenic stimulators. The mesenteric lymph nodes, thymus and nonlymphoid tissues, i.e. lung, kidney and liver, are not stimulated. The mitogenic effect peaks at day 3 with a second minor peak at day 7 and disappears by day 9. The mitogenic effect is unrelated to the ability of TAF and PEF to abrogate lymphocyte trapping.