Objective The objective of the present study was to evaluate the effect of bleomycin sulfate on parameters related to the functionality of pancreatic tissue, with emphasis on the glucose tolerance test, insulin tolerance test, insulinemia and static secretion of insulin as well as the insulin receptor, and PKA, PKC and GLUT2 concentrations in the pancreatic islets. Design Twenty-four male rats were divided into 2 groups: control and treated with bleomycin (2.5 mg/kg, intratracheal mode). After 7 days, the animals were euthanized and the analyses were carried out. Statistics The normality and the homoscedasticity of the data distribution were tested and ANOVA was applied. The Tukey post hoc test followed ANOVA for the comparison of the static insulin secretion test at different glucose concentrations. Results In the glucose tolerance test, the bleomycin group showed a larger area (17,306±539 mg/dLx60min) than that of the control group (9,151±517 mg/dLx60min) and in the insulin tolerance test, there was a greater percentage fall in glycemia (8.08±0.56%) in the bleomycin than in the control group (3.87±1.14%). The bleomycin group also presented a reduction in insulin secretion and an increase in plasmatic insulin concentration in the static insulin secretion test. With respect to the concentrations of the insulin receptor, GLUT2, PKC and PKA in the pancreatic islets of the bleomycin group, there was an increase in GLUT2 (48.4%) and PKC (70.8%) and a reduction in PKA (38.5%). Conclusion During treatment with bleomycin, innumerable chemical-metabolic alterations were unleashed in the tissues which were not primary targets of the chemical therapy and which could compromise the homeostasis of the systems taking part in the glycemic adjustment, predisposing the organism to the development of a pre-diabetic pattern whose degree of incidence or reversibility is still unknown to the scientific community.
Carlos Alberto da Silva, Karina M Cancelliero, Dirceu Costa