Carassius auratus as a novel model for the hyperglycemia study

Abstract

The aim of the present study was to create a suitable model of the glucose toxicity and elucidate the ability of zinc-binding proteins metallothioneins in the crucian carp Carassius auratus to reflect it. For that, fish was loaded by three waterborne concentrations of glucose (low (5.55 mM, LC), middle (55.5 mM, MC) or high (111 mM, HC)) for 21 days. The level of blood glucose, responses of metallothioneins, oxidative stress, DNA instability in the liver, as well as erythrocytes indices, cholinesterase activity in the brain and morphometric variables were evaluated. An increase in blood glucose levels (up to 3–5 times), glycated hemoglobin (HbA1c, only by the HC, by 55%), methemoglobin (by two times), oxyradicals (16-57%) and TBARS levels (up to 57%), frequency of the micronucleated erythrocytes, DNA fragmentation in hepatocytes, body mass and hepatosomatic indices and a decrease in metallothioneins concentration (40-74%), cholinesterase activity (~70%), total hemoglobin (by 18%) and red blood cells count (only after HC-treatment, by 47%) were detected. The lysosomal membrane stability, evaluated by the neutral red retention time, was affected by all studied concentrations of glucose (decreased by 58%). The most prominent changes were observed after the HC of glucose. CART analysis revealed the significant splitting parameters for studied group differentiation including HbA1c, lysosomal membrane stability and lipid peroxidation. We could consider the crucian carp is a useful model organism to perform DM studies and in the future, this fish model can help in mechanistic investigations and testing therapeutic interventions under glycemic states.