Keratinocyte growth factor increases fatty acid mobilization and hepatic triglyceride secretion in rats.
Keratinocyte growth factor (KGF) is a member of the fibroblast growth factor family that was originally identified as a keratinocyte mitogen after isolation from a lung fibroblast cell line. In this study, we demonstrate that administration of KGF to mice and rats elevates serum lipid levels. In rats, 1 h after KGF administration, serum triglyceride and FFA levels were increased, with peak values at 2 h (1.9-fold increase). The increase in serum triglyceride levels was sustained for at least 16 h. Serum cholesterol levels were also increased, but the effect was delayed beginning at 4 h, with peak values at 16 h (1.27-fold increase). KGF did not decrease the clearance of triglyceride-rich lipoproteins, but increased hepatic triglyceride secretion. KGF stimulated lipolysis, but not hepatic de novo fatty acid synthesis, and the increased delivery of FFA to the liver plays a crucial role in the KGF-induced hypertriglyceridemia. Neither alpha- nor beta-adrenergic receptor antagonists affected the hypertriglyceridemia induced by KGF, indicating that endogenous catecholamines are not involved in mediating KGF-induced hypertriglyceridemia. These results demonstrate that KGF induces hypertriglyceridemia by increasing hepatic triglyceride secretion, with the fatty acids provided by lipolysis making a major contribution. Thus, KGF could modulate lipid metabolism in vivo.
Nonogaki
K
K
Department of Medicine, University of California, San Francisco 94143, USA.
Pan
X M
XM
Moser
A H
AH
Staprans
I
I
Feingold
K R
KR
Grunfeld
C
C
D000818:Animals; D002914:Chylomicrons / Q000378:metabolism; D005227:Fatty Acids / Q000378:metabolism*; D051526:Fibroblast Growth Factor 10; D051523:Fibroblast Growth Factor 7; D005346:Fibroblast Growth Factors; D006133:Growth Substances / Q000494:pharmacology*; D008055:Lipids / Q000097:blood; D008066:Lipolysis; D008099:Liver / Q000187:drug effects* / Q000378:metabolism; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D051381:Rats; D017207:Rats, Sprague-Dawley; D014280:Triglycerides / Q000378:metabolism*
D002914:Chylomicrons; D005227:Fatty Acids; C496454:Fgf7 protein, mouse; C496455:Fgf7 protein, rat; D051526:Fibroblast Growth Factor 10; D006133:Growth Substances; D008055:Lipids; D014280:Triglycerides; D051523:Fibroblast Growth Factor 7; D005346:Fibroblast Growth Factors