Stimulatory effect of insulin-like growth factor-I on [3H]thymidine incorporation, DNA content and insulin biosynthesis and secretion of isolated pancreatic rat islets.
The influence of insulin-like growth factor-I (IGF-I) on both the growth and function of isolated pancreatic rat islets was studied. As a measure of islet cell replication, [3H]thymidine incorporation and DNA content was estimated at the same time as parameters for (pro)insulin biosynthesis and secretion as a measure of the functional capacity of B cells. Incorporation of [3H]thymidine was measured after tissue solubilization; DNA was determined fluorometrically. (Pro-)insulin biosynthesis was determined by incorporation of [3H]leucine after immunoprecipitation and binding to protein A-Sepharose. There was a significant increase in both [3H]thymidine incorporation and DNA content after the culture of islets with IGF-I. IGF-I resulted also in an increase in insulin biosynthesis and secretion from isolated pancreatic islets. These results demonstrate a role of IGF-I in regulating the growth and function of pancreatic islets.
Sieradzki
J
J
Department of Medicine III, University of Giessen, Federal Republic of Germany.
Fleck
H
H
Chatterjee
A K
AK
Schatz
H
H
D000818:Animals; D002478:Cells, Cultured; D004247:DNA / Q000378:metabolism*; D007328:Insulin / Q000378:metabolism*; D007334:Insulin-Like Growth Factor I / Q000494:pharmacology*; D007515:Islets of Langerhans / Q000187:drug effects* / Q000378:metabolism; D008297:Male; D051381:Rats; D011919:Rats, Inbred Strains; D013002:Somatomedins / Q000494:pharmacology*; D013268:Stimulation, Chemical; D013936:Thymidine / Q000378:metabolism*; D013997:Time Factors
D007328:Insulin; D013002:Somatomedins; D007334:Insulin-Like Growth Factor I; D004247:DNA; D013936:Thymidine