Cobalt Chloride and the Alpha-Cells of the Pancreas

Abstract

THE hyperglycæmic glycogenolytic factor found in the pancreas of normal and of alloxan-diabetic animals was assumed to be the product of the α-cells of the Langerhans islets¹. When administered parenterally, simple cobaltous salts damage selectively the α-cells², and were therefore considered useful for investigating whether the hyperglycæmic factor meets the criteria of a hormone. Since administration of cobaltous salts also elicits a transitory hyperglycæmia^2,3, it has been suggested that they initially excite the α-cells, and then cause them to degenerate². This hypothesis is invalidated by the facts that animals treated with cobalt chloride do not become hypoglycæmic and that repeated injections evoke transitory hyperglycæmic responses even after the α-cells are no longer demonstrable histologically³. Also, more of the hyperglycæmic factor could be extracted from the pancreas after such destruction of α-cells than from normal controls⁴. Ellis et al. ⁵ found that dihydroergotamine inhibits hyperglycæmia caused by cobalt chloride, but not the effect of the hyperglycæmic factor.