Serum free insulin-like growth factor-I is dose-dependently decreased by methylprednisolone and related to body weight changes in rats.
Glucocorticoids usually inhibit growth despite a paradoxical increase in total IGF-I. To investigate the effect of methylprednisolone on free IGF-I, rats were treated with for 3 days (0, 1, 2, 4, and 6 mg/kg per day). A dose-dependent decrease in ultrafiltrated serum free IGF-I was observed, being lowest after 6 mg/kg (P < 0.001 all groups vs controls). Total IGF-I was increased in the groups receiving 2 mg/kg (P < 0.05). Weight change in the 24 h prior to blood sampling was positively correlated with free IGF-I (R = 0.46, P = 0.0002), but not with total IGF-I. Immunoassayable IGFBP-1 was decreased in rats given 4 mg/kg (P = 0.001), whereas there was no change in IGFBP-3 or acid-labile subunit. We propose that in rats the glucocorticoid-induced weight loss may in part be due to suppression of circulating free IGF-I.
Skjaerbaek
C
C
Medical Research Laboratories, Aarhus University, Denmark. cs@afdm.aau.dk
Frystyk
J
J
Grøfte
T
T
Flyvbjerg
A
A
Lewitt
M S
MS
Baxter
R C
RC
Orskov
H
H
D000818:Animals; D001786:Blood Glucose / Q000187:drug effects / Q000378:metabolism; D001835:Body Weight / Q000187:drug effects / Q000502:physiology*; D002149:Energy Intake / Q000187:drug effects; D005215:Fasting; D005260:Female; D005938:Glucocorticoids / Q000008:administration & dosage / Q000494:pharmacology; D007279:Injections, Subcutaneous; D018970:Insulin-Like Growth Factor Binding Protein 1 / Q000097:blood; D018972:Insulin-Like Growth Factor Binding Protein 3 / Q000097:blood; D007334:Insulin-Like Growth Factor I / Q000187:drug effects / Q000378:metabolism*; D008775:Methylprednisolone / Q000008:administration & dosage / Q000494:pharmacology*; D051381:Rats; D017208:Rats, Wistar; D012044:Regression Analysis; D014462:Ultrafiltration
D001786:Blood Glucose; D005938:Glucocorticoids; D018970:Insulin-Like Growth Factor Binding Protein 1; D018972:Insulin-Like Growth Factor Binding Protein 3; D007334:Insulin-Like Growth Factor I; D008775:Methylprednisolone