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ABSTRACT
Insulin release was measured in Isolated pancreatic Islets prepared from fed female Wistar rats originating from five different colonies. in the reference animals routinely used in this laboratory, increasing concentrations of D-glucose (zero to 27.8 mM) stimulated insulin release, with a sigmoidal relationship (threshoid value 4.6 mM, half-maximal response at 9.7 mM) between secretory rates and hexose concentration. The amount of insulin released by the islets was proportional to the length of incubation. in the rats obtained from other colonies, a significant difference was found between animals of distinct sources for the ratio between glucose-stimulated and basal insulin output. There were significant correlations between such a ratio and the plasma insulin concentration or plasma insullnogenlc index. These findings reveal an interspecies heterogeneity in B-cell responsiveness to D-glucose, additional to those factors responsible for the heterogeneous secretory behavior of either individual B-cells or islets located in separate parts of the pancreatic gland.
Insulin release was measured in Isolated pancreatic Islets prepared from fed female Wistar rats originating from five different colonies. in the reference animals routinely used in this laboratory, increasing concentrations of D-glucose (zero to 27.8 mM) stimulated insulin release, with a sigmoidal relationship (threshoid value 4.6 mM, half-maximal response at 9.7 mM) between secretory rates and hexose concentration. The amount of insulin released by the islets was proportional to the length of incubation. in the rats obtained from other colonies, a significant difference was found between animals of distinct sources for the ratio between glucose-stimulated and basal insulin output. There were significant correlations between such a ratio and the plasma insulin concentration or plasma insullnogenlc index. These findings reveal an interspecies heterogeneity in B-cell responsiveness to D-glucose, additional to those factors responsible for the heterogeneous secretory behavior of either individual B-cells or islets located in separate parts of the pancreatic gland.