RESUMEN
BFU-E growth is enhanced significantly after addition of either non-stimulated or LPS-stimulated peritoneal macrophage culture supernatants. This supernatant shows positive and negative control on the growth of CFU-E and CFU-GM, low concentration supernatant shows promoting activity and high concentration supernatant presents inhibition. The LPS-stimulated supernatant shows much stronger promoting activities than non-stimulated supernatant. This supernatant has no obviously action on the proliferation of CFU-S. The mechanism of the regulation of mouse hemopoiesis by the conditioned media of the peritoneal macrophage is discussed. Our results show that this supernatant of cultured peritoneal macrophages may contain EPO-like, BPA-like and CSF-GM-like factors.