Stress-induced glucose uptake in bovine chromaffin cells: a comparison of the effect of arsenite and anisomycin

The effect of the toxic chemical Na-arsenite and the protein synthesis inhi bitor anisomycin on glucose transport in primary cultures of bovine chromaf fin cells was compared using the effect of insulin-like growth factor I (IG F-I) as a reference. The enhanced uptake of glucose obtained in response to arsenite and anisomycin reached maximum after 60 min, with the response to anisomycin being delayed in onset relative to that of arsenite. At maximal doses the arsenite effect was consistently higher than that of anisomycin and comparable to the similar to 2-fold effect produced by IGF-I. The selec tive inhibitor of stress-activated protein kinase 2 (SAPK2), SE 203580, inh ibited completely anisomycin-induced glucose uptake but only partly suppres sed uptake stimulated by arsenite. Both substances, in concentrations produ cing maximal effects on glucose transport, led to a strong phosphorylation of SAPK2. In contrast to the effect on glucose transport, the arsenite-indu ced phosphorylation of SAPK2 was relatively slow compared to the anisomycin -induced activation. The results indicate that glucose uptake induced by th e two types of cellular stress are mediated by at least two different signa ling pathways, which also differ from that activated by IGF-I. (C) 1999 Els evier Science B.V, All rights reserved.