Reactions induced in vertebrates by invertebrate cell suspensions. I/Specific effects of sea star axial organ cells injection.

Starfish axial organ cell suspensions injected subcutaneously into irradiated mice induce a characteristic angiogenesis reaction. The size of the reaction appears to be dependent upon the number of injected starfish cells. Axial organ cells also provoke a splenomegaly positive test in 16 day old chick embryos. No significant angiogenesis nor splenomegaly were induced by heat killed axial organ cells, ovocytes or branchial digestive organ cells. These results support our hypothesis that echinoid axial organ represents an ancestral primary lymphoid organ.