Figure 3.

Oxygen consumption and the response to glibenclamide in human islets treated with PIC with or without 12-LO inhibitor. (a) A representative figure (nondiabetic donor 3 of Fig. 2) comparing the OCR in human islets that were untreated (Cont), treated with PIC, or treated with PIC in the presence of ML355 for 24 hours (n = 3). (b) The OCR (as defined in the Methods) was compared among the Cont, PIC, and PIC plus ML355 groups, taking the average of the OCR in PIC-treated islets as 1. Data are mean ± standard error of the mean (SEM), combining three donors each in triplicate (n = 9). (c) Insulin secretion measured by batch assay at indicated concentrations of glucose with or without 10 μmol/L of glibenclamide in the Cont, PIC-treated, and PIC plus ML355−treated human islets. Insulin secretion was expressed by taking the average insulin secretion at 1 mmol/L glucose as 1. Data are mean ± SEM, combining four donors each in triplicate (n = 12). (d) Western blot compared total p38 (p38) and phospho-p38 (P-p38) in Cont, PIC-treated, and PIC plus ML355−treated human islets. The representative blot and the density of P-p38 corrected for p38 are shown (n = 3). (e) GSIS measured by batch assay at the indicated concentration of glucose in Cont, PIC-treated, PIC plus ML355−treated, and PIC plus SB203580 (p38i)−treated human islets. Insulin secretion was expressed by taking the average insulin secretion at 1 mmol/L glucose as 1. Data are mean ± SEM, combining two donors each in duplicate or triplicate (n = 4 to 6). *P < 0.05; **P < 0.01; ***P < 0.005 by Student t test.