PRODUCTION OF HEMATOPOIETIC REGULATORY FACTORS IN CULTURES OF ADULT AND FETAL MOUSE ORGANS - MEASUREMENT BY SPECIFIC BIOASSAYS

Factor-specific cell line bioassays were used to monitor the productio n in vitro by adult and fetal mouse organs of GM-CSF, G-CSF, M-CSF, Mu lti-CSF (IL-3), IL-6 and leukemia inhibitory factor (LIF). No tissue w as observed to produce Multi-CSF. Highest producers of the other regul ators were lung, muscle, thymus, heart and bone shaft and all tissues producing detectable growth factors produced all five with the same ra nk order of activity. Adult tissues produced more GM-CSF than G-CSF an d less M-CSF than either, no differences being observed between male, female and pregnant female tissues. In contrast, the pregnant uterus p roduced high levels of M-CSF as did the fetal membranes and tissues wi th only low GM-CSF and no G-CSF production. Pre-irradiation did not al ter the pattern of regulator production by adult tissues. The intraven ous injection of endotoxin elevated serum levels of GM-CSF, G-CSF, M-C SF and IL-6 but the dominant rise was in G-CSF levels. The data indica ting that multiple organs produce the regulators monitored in a common rank order suggest some overall linkage in their production with majo r differences between adult and fetal tissues.