Nitric oxide (NO) and caspase-8 in liver streptozotocin-induced diabetic rats

INGARAMO, PI; RONCO, MT; FRANCÉS, DE; GALLEANO, M; MONTI, JA; CEBALLOS, MP; CARRILLO, MC; CARNOVALE, CE

Santiago de Chile

Congreso; Free Radicals in Chile 2009. VI Meeting of SFRBM-South American Group.; 2009

SOCIETY FOR FREE RADICAL BIOLOGY AND MEDICINE

Introduction: Free radical production is involved in the pathogenesis ofDiabetes mellitus. Aim: To study the regulation of NO production byinducible nitric oxide shynthase enzyme (NOS2) in liver of diabetic rat andthe role of NO in caspase 8–induced apoptosis. Methodology: Adult maleWistar rats were randomized in 3 groups: (C) control (citrate buffer,pH=4.5), (D) diabetic (streptozotocin (SZ), 60 mg / kg of body weight (bw)ip), (D+I) diabetic with insulin (15 days post-SZ, 30 UI/kg bw, sc, threetimes a day during 15 days). Rats of three groups were treated with 100mg/kg bw of aminoguanidine (AG) a day for 10 days. 30 days post-injectionof SZ, rats of all groups were autopsied. Results: Glycemia (enzymaticmethod, g/l): C: 1.17±0.01; D:4.67±0.42*; D+I:0.85±0.01†. Bw (g):C:439±8; D:297±9*; D+I:421±13†. NO in blood (Electronic ParamagneticResonance (EPR), arbitrary unit (AU)): C: undetectable; D:22026±2571*;D+I: undetectable†. NO in liver total homogenate (EPR, AU). C:49305±21384; D:199877±67838*; D+I: 37238±6460†; D+AG: 51493±34127†; D+I+AG: 45150±27183†. Western blot, as percentage of C: NOS2in cytosol: D: 439.7±56.5*; D+I:238.0±66.0†, D+AG:265.3±55.4†;D+I+AG: 126.0±8.6†. Caspase-8 activity (colorimetric method, AU):C:3.8±1.8 D:57.8±2.7*; D+I:2.3±0.9†; D+AG:4.5±3.8†. *p