[Morphologic and radioautographic study of reactivation of peritoneal exudate cell nuclei in heterokarya]

The heterokaryons of undifferentiated mouse fibroblasts (L and 3T3-4E/TK-) and various cell elements of the rat peritoneal exudate were obtained under the treatment with inactivated Sendai virus. The reactivation of RNA and DNA synthesis in the nuclei of highly differentiated periotoneal exudate cells and the synthesis of thymidine kinase controlled by the nuclei of peritoneal exudate cells were shown to occur in the heterokaryons. During the process of reactivation, the ring-like nuclei of polymorphonuclear leucocytes acquired the form characteristic of the reactivated nuclei of mononuclears. The morphological changes of heparin-containing granules in the cytoplasm of the heterokaryons of mast cells and undifferentiated fibroblasts suggest the degeneration and breakdown of granules.