Insulin-like growth factor I does not inhibit insulin secretion in adult human pancreatic islets in tissue culture.
Insulin-like growth factor I (IGF-I) has been found to increase insulin sensitivity and suppress insulin secretion, thereby having a potential interest as a therapeutic agent for non-insulin-dependent diabetes mellitus (NIDDM). The aim of the present study was to investigate the direct actions of IGF-I (400 ng/ml) on human pancreatic islets, or on rat pancreatic islets, during a 48 h period in tissue culture. Insulin-like growth factor I did not affect medium insulin accumulation, DNA or insulin content or short-term glucose-induced insulin release of human islets. However, in rat islets the peptide induced a significant decrease in the insulin increase ratio in response to 16.7 mmol/l glucose. In conclusion, the present data suggest that IGF-I does not directly affect the function of human pancreatic beta-cells. If this in vitro data can be extrapolated to the in vivo situation, it suggests that the observed inhibitory effects of IGF-I on serum insulin levels may be secondary to peripheral effects of the peptide.
Eizirik
D L
DL
Department of Medical Cell Biology, Uppsala University, Sweden.
Skottner
A
A
Hellerström
C
C
D000328:Adult; D000818:Animals; D046508:Culture Techniques; D004247:DNA / Q000378:metabolism; D005947:Glucose / Q000494:pharmacology; D006801:Humans; D007328:Insulin / Q000378:metabolism*; D000078790:Insulin Secretion; D007334:Insulin-Like Growth Factor I / Q000494:pharmacology*; D007515:Islets of Langerhans / Q000187:drug effects* / Q000378:metabolism*; D008875:Middle Aged; D051381:Rats; D017207:Rats, Sprague-Dawley
D007328:Insulin; D007334:Insulin-Like Growth Factor I; D004247:DNA; D005947:Glucose