We studied the effect of the myo-inositol content of culture media on several of the functional characteristics of cultured adult rat pancreatic islets. Variations in the ambient myo-inositol concentration had no effect on insulin content, its rate of synthesis, or its secretion in response to glucose when studied in freshly isolated islets. However, myo-inositol did inhibit the incorporation of 3H-thymidine into the DNA of the fresh islet. When islets were cultured for 6 days in the absence of myo-inositol, their basal rate of insulin secretion was elevated and they were unresponsive to an elevated glucose concentration. As the myo-inositol content of the culture medium was increased from 10 to 40 μg/ml, a progressive decrease in basal insulin secretion as well as an increase in glucose-stimulated insulin secretion was observed. Similarly, the total insulin content of cultured islets increased progressively as the myo-inositol content of the culture medium was raised. The rates of incorporation of 3H-leucine into islet protein, proinsulin, insulin, and Cpeptide were found to be twice as high in the presence of 40 μg/ml myo-inositol when compared with the rates observed in the absence of this material. The incorporation of 3H-thymidine into the DNA of cultured islets was maximal when the medium contained 20 μg/ml myo-inositol, and was decreased when concentrations above or below this value were employed. These results demonstrate that the ambient myo-inositol concentration to which cultured islets are exposed in vitro exerts a strong influence on their functional characteristics. Thus, the myo-inositol content of the culture media employed should be taken into consideration in the interpretation of any studies involving cultured pancreatic islets.
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Original Contributions|
August 01 1981
Myo-lnositol and the Maintenance of β-Cell Function in Cultured Rat Pancreatic Islets
Address reprint requests to Dr. Caroline S. Pace, Diabetes Hospital, 1808 Seventh Avenue South, University of Alabama in Birmingham, Birmingham, Alabama 35294.
Diabetes 1981;30(8):621–625
Article history
Received:
February 18 1981
Citation
Caroline S Pace, Rex S Clements; Myo-lnositol and the Maintenance of β-Cell Function in Cultured Rat Pancreatic Islets. Diabetes 1 August 1981; 30 (8): 621–625. https://doi.org/10.2337/diab.30.8.621
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