Systematic Analysis of the Insulinotropic and Glucagonotropic Potency of Saturated and Monounsaturated Fatty Acid Mixtures in Rat Pancreatic Islets

Abstract

Background: Blood contains a mixture of different fatty acids (FFAs) with palmitate and oleate as major components whose molar ratio is dependent on dietary habits. Based on the theory of lipotoxicity for the development of type 2 diabetes such variances in the FFA composition might interfere with lipotoxic effects on the endocrine pancreas.

Methods: Using different ratios of FFA mixtures with palmitate and oleate, we have looked at FFA specific effects on the secretion of mature insulin and glucagon in isolated rat pancreatic islets.

Results: The insulinotropic potency of the oleate dominated FFA solutions was stronger than that of the palmitate dominated FFA mixtures. Conversely, the glucagonotropic potency was stronger in the palmitate dominated FFA mixtures. Palmitate and oleate similarly contributed to an impaired release of mature insulin at 16.7 mM of glucose.

Conclusion: Based on the present in vitro data, FFA specific differences in terms of glucagonotropic and insulinotropic potency appear rather slight. For the in vivo situation, it may be assumed that the dietary influence of saturated and monounsaturated fatty acids on hyperproinsulinemia or hyperglucagonemia are rather secondary for the development of type 2 diabetes.

Key words

Free fatty acids - immunoreactive insulin - c-peptide - glucagon - pancreatic islet

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