Administration of growth hormone modulates the gene expression of basic fibroblast growth factor in rat costal cartilage, both in vivo and in vitro.
We examined the effect of growth hormone on local growth factor mRNA expression in male Sprague-Dawley rats. Repetitive systemic administration of growth hormone (0.4 IU every 4 h) increased the expression of IGF-I mRNA up to 2.8-fold in costal cartilage tissue compared with controls. Basic FGF (bFGF) mRNA expression gradually increased up to 15.5-fold compared with pre-injection samples, where the mRNA expression was 5.3-times greater than vehicle-injected controls. TGF-beta mRNA showed little changes. Moreover, one microgram/ml of growth hormone enhanced the expression of bFGF mRNA in costal chondrocytes in culture. We conclude that growth hormone increased the local expression of bFGF, as well as that of IGF-I, in cartilage, and suggest that bFGF is directly regulated by growth hormone within a local area.
Izumi
T
T
Department of Orthopedic Surgery, Kyushu University, Fukuoka, Japan.
Shida
J
J
Jingushi
S
S
Hotokebuchi
T
T
Sugioka
Y
Y
D000818:Animals; D015152:Blotting, Northern; D002356:Cartilage / Q000378:metabolism*; D002478:Cells, Cultured; D016222:Fibroblast Growth Factor 2 / Q000235:genetics*; D015870:Gene Expression / Q000187:drug effects*; D013006:Growth Hormone / Q000008:administration & dosage / Q000097:blood / Q000494:pharmacology*; D007334:Insulin-Like Growth Factor I / Q000235:genetics; D007700:Kinetics; D008297:Male; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D016212:Transforming Growth Factor beta / Q000235:genetics
D012333:RNA, Messenger; D016212:Transforming Growth Factor beta; D016222:Fibroblast Growth Factor 2; D007334:Insulin-Like Growth Factor I; D013006:Growth Hormone