RESUMO
The correlative effects of the two sulphydryl inhibitors viz., the mono-and dithiol reagent, alloxan and cobalt chloride, were studied in the fresh water air breathing catfish, Clarias batrachus. Alloxan induced a typical mammalian-like triphasic response and necrobiotic changes in the islet β-cells. Cobalt chloride elicited a discontinuous hyperglycemia with cytopathological changes in β-cells following nearly the same sequence as those induced by alloxan. However, the α-cells of cobalt-treated fish showed, unlike those after alloxanization, specific degranulation, vacuolization and nuclear enlargement. The changes in the hepatic glycogen content of two experimental groups were observed to be equal. Both the drugs appeared to be detrimental to the normal islet function and were, thus, overtly or potentially diabetogenic agents to the fish.