Different effects of growth hormone on growth and function of isolated adult and fetal rat pancreatic islets.
We simultaneously determined 3H-thymidine incorporation, DNA content, and insulin biosynthesis in adult and fetal rat pancreatic islets. 3H-thymidine incorporation was measured after tissue solubilization. DNA was measured fluorometrically. Insulin biosynthesis was determined through 3H-leucine incorporation after immunoprecipitation and binding to protein A-sepharose. Addition of growth hormone caused a significant increase in 3H-thymidine incorporation into both the adult and the fetal islets, but only the adult islets experienced an increase in DNA content. The increase in 3H-leucine incorporation was also significant only in the adult islets. The dynamics of 3H-thymidine incorporation after growth hormone administration were different in the adult and the fetal pancreas. Fetal islets have the potential to increase their incorporation of 3H-thymidine, but very limited potential for insulin biosynthesis.
D000818:Animals; D002455:Cell Division / Q000187:drug effects; D002478:Cells, Cultured; D004247:DNA / Q000096:biosynthesis; D004261:DNA Replication / Q000187:drug effects; D005333:Fetus; D013006:Growth Hormone / Q000494:pharmacology*; D007328:Insulin / Q000096:biosynthesis / Q000378:metabolism; D000078790:Insulin Secretion; D007515:Islets of Langerhans / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D007700:Kinetics; D007930:Leucine / Q000378:metabolism; D014176:Protein Biosynthesis; D051381:Rats; D013936:Thymidine / Q000378:metabolism; D014316:Tritium
D007328:Insulin; D014316:Tritium; D013006:Growth Hormone; D004247:DNA; D007930:Leucine; D013936:Thymidine