The imidazoline compound RX871024 reduces IL-I beta-induced NO production thereby protecting against IL-I beta-induced beta-cell apoptosis. The aim of this study was to evaluate whether imidazolines RX871024 and efaroxan protect beta-cells against death in the presence of a combination of the cytokines IL-1 beta, IFN gamma, and TNF alpha. To address this issue, experiments involving different methods for detection of cell death, different concentrations of the cytokines, and a variety of conditions of preparation and culturing of ob/ob mouse islets and P-cells have been carried out. Thoroughly performed experiments have not been able to demonstrate a protective effect of RX871024 and efaroxan on beta-cell death induced by the combination of cytokines. However, the inhibitory effect of RX871024 on NO production in ob/ob mouse islets and P-cells was still observed in the presence of all three cytokines and correlated with the decrease in p38 MAPK phosphorylation. Conversely, efaroxan did not affect cytokine-induced NO production. Our data indicate that a combination of pro-inflammatory cytokines IL-I beta, IFN gamma, and TNF alpha conditions modelling those that take place in type 1 diabetes, induces pancreatic P-cell death that does not directly correlate with NO production and cannot be counteracted with imidazoline compounds. (c) 2006 Elsevier Inc. All rights reserved.