Figure 5

Chronic glucolipotoxicity in vitro impairs calcium release. Rat islets and NIT-1 cells were cultured under normal conditions (control) or with 16.7 mM glucose and 500 μM palmitate for 72 h (GL). Post 72 h, islet IP3 levels (A) were estimated in the presence of 11 mM (HG) as described in the materials and methods. For cytosolic calcium mobilization assay (B and C), post treatment NIT-1 cells were loaded with Fluo-3AM calcium indicator dye for 1 h. After washing the cells, they were treated with either low (2.5 mM) or high (16.7 mM) glucose and the change in fluorescence was estimated as described in the materials and methods. Data are expressed as mean±SEM and statistical analysis was performed using the unpaired Student’s t-test. (*P<0.05, **P<0.01 and ***P<0.001, n=4).