Histological changes in the hyperglycemic Wistar rat treated with insulin at non-normoglycemic doses

Introduction: the use of insulin in models of experimental diabetes is still controversial. Objective: to evaluate the effect of hyperglycemia for a long time at a systemic level in hyperglycemic subjects treated with insulin at non-normoglycemic doses. Methods: an experimental (analytical), longitudinal study conducted. Hyperglycemia (glucose levels ~ 500mg/dl) was induced in Wistar rats (hyperglycemic group, n=4); they were administered aloxan (intraperitoneal, 150mg/kg) and were protected, simultaneously, with insulin (0.25-0.5U/kg) for 42 days. Samples of liver, pancreas, kidney and retina were obtained and stained with the hematoxylin and eosin technique. Histological changes and cell count were identified when compared with normoglycemic rats (normoglycemic group, n=4) by Student’s t-test, p<0.05. Results: a hyperglycemia model was obtained. In the hyperglycaemic group, at the hepatic level, it was observed dilatation of sinusoids, thick-film steatosis and low cell count (t7=3.52, p <0.009); at renal level, tubular lysis, erythrocytic infiltrate and low cell count (t7=3.74, p <0.007) were found; at the pancreatic level, it was observed a dilation of duct-acinar units of the exocrine portion without changes in the cell count (t7=-2.05, p=0.078), and the retina showed no structural changes or in the cell count (t5=-1, 86; p=0.120). Conclusions: the insulin used at non-normoglycemic doses does not inhibit the long-term histological, biochemical and behavioral effects of hyperglycemia, but does promote the survival of the study subjects.Introducción: el empleo de insulina en modelos de diabetes experimental aún es controversial. Objetivo: evaluar el efecto de la hiperglucemia por tiempo prolongado a nivel sistémico en sujetos hiperglucémicos tratados con insulina a dosis no normoglucemiantes. Métodos: se efectuó un estudio de tipo experimental (analítico), longitudinal. Se indujo hiperglucemia (niveles de glucosa ~500mg/dl) en ratas Wistar (grupo hiperglucémico, n=4); se les administró aloxan (intraperitoneal, 150mg/kg) y se les protegió, simultáneamente, con insulina (0,25-0,5U/kg) durante 42 días. Se obtuvieron muestras de hígado, páncreas, riñón y retina que fueron teñidas con la técnica de hematoxilina y eosina. Se identificaron cambios histológicos y recuento celular al comparar con ratas normoglucémicas (grupo normoglucémico, n=4) mediante la prueba t de Student, p<0,05. Resultados: se obtuvo un modelo de hiperglucemia. En el grupo hiperglucémico se observaron, a nivel hepático, dilatación de sinusoides, esteatosis de gota gruesa y bajo recuento celular (t7=3,52; p<0,009); a nivel renal lisis tubular, infiltrado eritrocitario y bajo recuento celular (t7=3,74; p