The aim of the present study is to investigate the role of
hyperglycemia and hyperinsulinemia in autophagy induction in the
liver of male mice. Autophagy is a catabolic cellular process that
recycles the aged or damaged cellular organelles and inclusions
under certain circumstances. Hyperglycemia is induced by a
single dose of alloxan IP injection (180 mg/kg) and
hyperinsulinemia is induced by high fat diet together with glucose
feeding for short period (2 weeks) and long period (3 months).
Hyperglycemia and hyperinsulinemia were estimated by
measuring blood glucose level by glucometer and insulin level by
specific ELISA kit, respectively. Autophagy induction was
investigated morphologically by electron microscopy examination
and biochemically by immunodetection of microtubular associated
light chain protein 3 (LC3) conversion from LC3I to LC3II form
and by immunodetection of the phosphorylated and nonphosphorylated
forms of mammalian target of Rapamycin
(mTOR). Our results revealed that hyperglycemia and
hyperinsulinemia independently induced hepatocellular autophagy
as indicated by the accumulation of autophagosomes and
autolysosomes in EM examination and by the increase of the level
of LC3II and decrease of the phosphorylated form of mTOR in
western blot analysis. This study throw the light on the autophagy
of hepatocytes as a cellular mechanism induced under diabetic
conditions which may contribute in better understanding of our
knowledge concerning nutrients metabolic disorders.