Fig. 1. Cytokines regulate the production of IB1/JIP-1. Western-blot analysis of INS-1 cellular extracts revealed that the levels of IB1/JIP-1 decreased by 80% in INS-1 cells and in freshly isolated rat islets treated with cytokines [IL-1ß (2x10⁵ units µg^–1) TNF- (10⁵ units µg^–1) and IFN- (10 ng ml^–1)] during a period of 24 hours compared with controls (Ctrl). All lanes were loaded with 50 µg total proteins and normalized with tubulin (Tub).