Fig. 5.

Lack of effect of rapamycin on the electrical activity of islets exposed to glucotoxicity. The determination of electrical activity of pancreatic islets indicates that, after a 72 h-exposure to glucotoxicity, islets become electrically hyperactive (b) compared to islets cultured under standard conditions (a) as indicated by the evaluation of the time with electrical activity (FOPP: fraction of plateau phase; d−e). Inhibition of mTOR with rapamycin (1 nM) does not protect against this glucotoxicity-mediated alteration (c−e) but even trends to further elevate the FOPP. Circles indicate the number of islets evaluated from four independent mouse preparations (~ 8-months of age, female mice). *p < 0.05; **p < 0.01