On the Cobalt-concentrating Ability of Pancreatic Islet Tissue: A Histological, Histochemical, and Autoradiographical Investigation

Abstract

In experiments on the marine teleost Cottus scorpius using recently modified autoradio-graphic and histochemical procedures, it was possible to localize the easily dissolvable cobalt compounds that accumulate in pancreatic islet tissue. It was found that the [beta] cells, and possibly also the [alpha]1 cells, concentrate the metal. The [alpha]2 cells and the agranular parenchymal cells showed no affinity for cobalt. It was tentatively supposed that the cobalt-concentrating ability of the [beta] cells might be related to the high power of cobalt to crystallize insulin and that parts of the cobalt-induced blood glucose fluctuations might be due to transient [beta]cell changes induced by the complex-forming capacity of cobalt with sulfhydryl compounds. No account can be given for the biological significance of the possible cobalt accumulation in the a1 cells. It is concluded that the well-known transient hydropic changes seen in some mammalian glucagon-producing [alpha]2 cells, and the blood glucose fluctuations are not thought to be due to a direct cellular action of cobalt on the [alpha]2 cells.