Acidic fibroblast growth factor (FGF(1)) increases survival and haematopoietic recovery in total body irradiated C3H/HeNCr mice

Basic fibroblast growth factor is known to stimulate the proliferation of bone marrow stem and/or progenitor cells in vitro and in vivo, We examined a similar cytokine, acidic fibroblast growth factor (FGF(1)), for its in vivo radiomodifying effects, Female C3H/HeNCr mice were given human recombinant FGF(1) intravenously at doses ranging from 1 to 24 pg. FGF(1) was delivered in two equal doses 24 and 4 h before or 24 h after otherwise lethal total body irradiation (TBI), In vivo FGF(1) radioprotection of C3H mice was maximized at a total dose of 12 mu g/mouse given before TBI. The radiomodification was 1.16 +/- 0.03 (+/- SD) with an increase of LD(50/30) from 736 +/- 9 to 854 +/- 16 cGy (P < 0.01), Some retroactive radiomodification was observed even when FGF(1) was given 24 h after irradiation (P < 0.05). FGF(1) radioprotected mice by improving the repopulation of haematopoietic progenitor cells of bone marrow, The radioprotection was not associated with an increase in S-phase fraction or detectable circulating IL-3, TNF-alpha or GM-CSF, suggesting that other mechanisms of protection were responsible, (C) 1997 Academic Press Limited.