Significance of serum for the preservation of insulin secretion during culture.
The effects of serum and serum fractions on the maintenance of glucose-stimulated insulin secretion during culture of pancreatic islets were studied. The basal insulin release was independent of previous culture with serum but glucose-stimulated secretion increased with serum concentrations up to 0.3% which was sufficient for maximal effect. Although a high molecular size fraction (greater than 30,000 daltons) possessed the full activity of serum it is possible that the active principles are lighter compounds bound to serum proteins. Whereas the islet content of insulin was unaffected by culture with 3% serum, the presence of serum tended to increase the levels of pyridine nucleotides and the uptake of intracellular 45Ca in response to glucose. The sites of action for the serum factors are, therefore, the stimulus-secretion coupling and hormone discharge mechanisms rather than insulin biosynthesis.
D000818:Animals; D001769:Blood; D002478:Cells, Cultured; D003470:Culture Media; D007328:Insulin / Q000378:metabolism*; D000078790:Insulin Secretion; D007515:Islets of Langerhans / Q000378:metabolism*; D051379:Mice
D003470:Culture Media; D007328:Insulin