Heterogeneity in pancreatic beta-cell population.
All pancreatic beta-cells are identified by specific morphological characteristics. Similarity in microscopic features is not necessarily associated with identity in functional properties. In vitro studies on isolated rat beta-cells have indicated intercellular differences in the threshold for glucose-induced shifts in metabolic redox state. The cellular heterogeneity in glucose sensitivity results in a dose-dependent recruitment of glucose-exposed beta-cells into biosynthetic and secretory activities. The molecular basis of this diversity is not known. Indirect evidence supports the concept that the in situ pancreatic beta-cell population is also composed of functionally diverse subpopulations. The heterogeneity in glucose responsiveness is expected to create subpopulations of beta-cells with either constant, fluctuating, or occasional glucose-dependent functions; whether any subpopulation is preferentially responsive to other regulatory factors and/or committed to other activities is unknown. Morphological markers may help identify beta-cell subpopulations in situ and quantify their size in conditions known to affect total beta-cell mass or function. The concept of a functionally heterogeneous beta-cell population influences views on the role of pancreatic beta-cells in health and disease.
Pipeleers
D G
DG
Department of Metabolism and Endocrinology, Vrije Universiteit Brussels, Belgium.
D000818:Animals; D005947:Glucose / Q000494:pharmacology; D007515:Islets of Langerhans / Q000166:cytology* / Q000187:drug effects / Q000502:physiology; D008954:Models, Biological
D005947:Glucose