Experimental hemolysis model to study bilirubin encephalopathy in rat brain.

None of experimental models used to study the toxic effect of unconjugated bilirubin brain accumulation, reproduce the conditions in which the hyperbilirubinemia is a consequence of a hemolytic process, i.e. when important amounts of bilirubin and iron are released. The aim was to develop an animal model to determine the role of bilirubin and iron, in the encephalopathy secondary to a hemolytic disease. Male Wistar rats 7 days old (n=30) were treated with phenylhydrazine as hemolytic at 75 mg/kg body weight intraperitoneally for 2 days and euthanized 24 h after the last dose. Hemoglobin, hematocrit, serum and brain bilirubin, serum iron and lipoperoxidation products, as well as neuronal damage and iron positive staining were evaluated and compared among treated and untreated (n=10) animals. The animals with induced hemolysis showed significant reduction in hemoglobin and hematocrit, increased concentration of total and conjugated bilirubin, as well as of serum iron and lipid peroxidation products. The neuronal damage in treated animals included the presence of altered neurons spread out among normal cells, as well as of iron-staining positive cells. With the use of appropriated pharmacological procedures, the characteristics of the model can be useful to dissect the participation of both bilirubin and iron, on the bilirubin encephalopathy secondary to hemolysis.

Antioxidant effects of selenium in rat brain and the stimulating role of nitric oxide.

OBJECTIVE: To evaluate the antioxidant effect of selenium on Na+, K(+)-ATPase in rat brain in the presence of nitric oxide. METHODS: Male Wistar rats (70 g) were treated as follows: group 1 received 1 microg of i.p. sodium nitroprus-side per kg (SNP), group 2 received 5 microg sodium selenite during 20 days, group 3 received sodium selenite 5 microg + SNP 1 microg and the control group received vehicle 50 microl (0.9% NaCl), same period and route. At the end of treatment, animals were sacrificed and their brain dissected into cortex, hemispheres, cerebellum and brain stem in order to determine lipid peroxidation (TBARS), Na+, K+ ATPase and total ATPase in each section. Blood hemoglobin concentration (Hb) and prostate weight were also assessed. RESULTS: A significant increase of Hb in blood and of proteins in cortex and hemisphere was detected, but TBARS values fell due to the effect of sodium selenite in all examined regions, except for cerebellum. ATPase activity declined in all groups and regions with and without NTP. We conclude that diet supplementary selenium to inhibit NO generation can be a useful treatment in chronic inflammatory diseases.