Endotoxin decreases serum IGFBP-3 and liver IGFBP-3 mRNA: comparison between Lewis and Wistar rats.
We studied the IGFBP-3 response to endotoxin, in Wistar and Lewis rats. Compared to Wistar rats, Lewis rats have a reduced adrenal and IGF-I response to inflammatory stimuli. Rats received two injections of 1 mg/kg of lipopolysaccharide (LPS) and were killed 4 h after the second injection. LPS decreased serum concentrations of GH in Wistar (P<0.05), but not in Lewis rats. However, serum IGFBP-3 was decreased both in Wistar and in Lewis rats. Furthermore, LPS administration decreased IGFBP-3 gene expression in the liver in both rat strains (P<0.01). Lewis rats had lower serum IGFBP-3 than Wistar rats (P<0.01). This difference could be secondary to the increased IGFBP-3 proteolysis in serum observed in Lewis rats. These data indicate that acute inflammation inhibits serum concentrations of IGFBP-3 by decreasing its synthesis in the liver, rather than increasing its proteolysis. This effect seems to be GH and IGF-I independent.
Priego
T
T
Departmento de Fisiología, Facultad de Medicina, Universidad Complutense, 28040 Madrid, Spain.
Ibáñez de Cáceres
I
I
Martín
A I
AI
Villanúa
M A
MA
López-Calderón
A
A
D000818:Animals; D010450:Endopeptidases / Q000378:metabolism; D007249:Inflammation / Q000097:blood; D018972:Insulin-Like Growth Factor Binding Protein 3 / Q000096:biosynthesis / Q000097:blood / Q000187:drug effects*; D008070:Lipopolysaccharides / Q000494:pharmacology*; D008099:Liver / Q000378:metabolism*; D008297:Male; D012333:RNA, Messenger / Q000096:biosynthesis / Q000187:drug effects; D051381:Rats; D011917:Rats, Inbred Lew / Q000378:metabolism*; D017208:Rats, Wistar / Q000378:metabolism*
D018972:Insulin-Like Growth Factor Binding Protein 3; D008070:Lipopolysaccharides; D012333:RNA, Messenger; D010450:Endopeptidases