Efeito da derivação duodeno-jejunal sobre a secreção de insulina em ratos obesos pela dieta de cafeteria

Abstract

This study was designed to evaluate whether DJB in western diet (WD)-obese rats could have effects on pancreatic β-cell morphology and islet responsiveness to potentiating agents involved with the protein kinase A (PKA) and C (PKC) pathway. Male Wistar rats with 8 weeks of life were fed a standard rodent chow diet (CTL group) or WD ad libitum. After 10 weeks, WD rats were submitted to sham operation or DJB, forming WD SHAM and WD DJB group, respectively. After two months, the obesity parameters, insulin resistance (IR), pancreas morphology, insulin secretion stimulate by different secretagogues and islet protein expression were verified. WD SHAM rats displayed obesity, hyperglycemia, hyperinsulinemia, glucose intolerance and IR. In addition, they also presented an increase in islets and β-cells area and mass. The glucose-induced insulin secretion stimulated by 11.1 mM glucose in the presence of carbachol (CCh), PMA, Forskolin or IBMX was higher in WD SHAM islets than CTL islets. DJB surgery did not alter body weight but normalized glucose, insulinemia, IR, and decreased islet and β-cells mass. The insulin release stimulated by glucose in the presence of CCh, PMA, Forskolin or IBMX was too normalized in WD DJB group. The expression of glucokinase, PKC, PKA and sintaxin was not altered in WD SHAM rats, but the M3 receptor was down-regulated. DJB did not influence these protein expressions. DJB surgery normalized glicemia, insulinemia and IR, reduced islets and β-cell mass and normalized insulin secretion by PKC and PKA pathway.