Octreotide effect on insulin release, proliferation, mtDNA, and PPY secretion of INS-1E cells. (a) Glucose-stimulated insulin release from INS-1E cells, evaluated as the difference between time courses assayed with 25 mM glucose and without glucose up to 30 min, in the absence (black bar) and after a 60 min pretreatment with 50 nM octreotide (dashed bar); ∗∗∗
p < 0.001 (n = 3). (b) Proliferation (relative number of cells related to zero time) of INS-1E cells for 3 various cultivations at 3 mM glucose “3 mM Glc”, that is, at suppressed autocrine insulin, or at standard 11 mM glucose, in the presence of 10 nM octreotide (dashed bars) or octreotide plus supplemented 0.2 μM human insulin “+Ins” (white bars, ∗∗
p < 0.01; ∗∗∗
p < 0.001); (c) mitochondrial DNA copy number in INS-1E cells, after 3 or 4 passages “pass.” of cultivation in the absence (black bars) or presence of 1 μM octreotide (dashed bars, ∗∗
p < 0.05; n = 6). (d) PPY in medium of control (black bar) and octreotide-treated (1 μM, +Octr, dashed bar) INS-1E cells, after 3 passages of cultivation (∗∗
p < 0.05; n = 6).