Effect of morphine and lacosamide on levels of dopamine and 5-HIAA in brain regions of rats with induced hypoglycemia.

The study aimed to determine the effect of morphine and lacosamide on levels of dopamine and 5-HIAA in a hypoglycemic model. Female Wistar rats (n = 30), mean weight of 180 g were treated as follow: Group 1 (control) received 0.9% NaCl, Group II; morphine (10 mg kg(-1)), Group III; lacosamide (10 mg kg(-1)), Group IV; insulin (10 U.I. per rat), Group V; morphine (10 mg kg(-1))+insulin, Group VI; lacosamide (10 mg kg(-1))+ insulin. All administrations were made intraperitoneally every 24 h, for 5 days. Animals were sacrificed after the last dose to measure the levels of glucose in blood; dopamine and 5-HIAA in cortex, hemispheres and cerebellum/medulla oblongata regions. Levels of glucose decreased significantly in animals treated with morphine, lacosamide and all groups that received insulin alone or combined with respect to control group. Levels of Dopamine diminished significantly in cortex and increased significantly in hemispheres of animals that received morphine. In cortex, 5-HIAA increase significantly in the groups treated with morphine, morphine+insulin and lacosamide+insulin, however a significant decrease of the same substance was witnessed in cerebellum and medulla oblongata of animals that received morphine or lacosamide plus insulin. GSH increased significantly in cortex and cerebellum/medulla oblongata of animals treated with morphine and lacosamide alone or combined with insulin. Lipid peroxidation decreased significantly in cortex and cerebellum/medulla oblongata of groups that received lacosamide alone or combined with insulin. These results indicate that hypoglycemia induced changes in cellular regulation while morphine and lacosamide are accompanied by biochemical responses.

Effect of nicotine on ATPase, catalase and calcium levels in the presence of oligoelements in brain regions of young rats.

UNLABELLED: The effect of nicotine on membrane alterations and fluidity changes in very young models remains unclear. The aim of this study was to evaluate the effect of nicotine on total ATPase, H(2)O(2) and calcium in brain of young rats in the presence of oligoelements. Male Wistar rats (weight 80 g) received intraperitoneally either a single dose or repeated doses for 4 days as follows: Group 1 (control) NaCl 0.9%; group 2 nicotine (1mg/kg); group 3 oligoelements (50 µl); and group 4 nicotine (1mg/kg) + oligoelements (50 µl). The brain regions (cortex, hemispheres and cerebellum + medulla oblongata) of each rat were then obtained to measure the concentrations of total ATPase, H(2)O(2) and calcium using spectrophotometric methods. RESULTS: Total ATPase increased significantly (p < 0.05) in groups treated with oligoelements in repeated doses in hemisphere region, and in groups that received oligoelements + nicotine in single or repeated doses in medulla oblongata. Catalase showed significant decreased in cerebellum/medulla oblongata. Results suggest that nicotine induces changes in membrane fluidity in brain of young rats, and that ATPase could be a biomarker of nicotine consumption in young subjects.

The effect of aspartame on rat brain xenobiotic-metabolizing enzymes.

This study demonstrates that chronic aspartame (ASP) consumption leads to an increase of phase I metabolizing enzymes (cytochrome P450 (CYP)) in rat brain. Wistar rats were treated by gavage with ASP at daily doses of 75 and 125 mg/kg body weight for 30 days. Cerebrum and cerebellum were used to obtain microsomal fractions to analyse activity and protein levels of seven cytochrome P450 enzymes. Increases in activity were consistently found with the 75 mg/kg dose both in cerebrum and cerebellum for all seven enzymes, although not at the same levels: CYP 2E1-associated 4-nitrophenol hydroxylase (4-NPH) activity was increased 1.5-fold in cerebrum and 25-fold in cerebellum; likewise, CYP2B1-associated penthoxyresorufin O-dealkylase (PROD) activity increased 2.9- and 1.7-fold respectively, CYP2B2-associated benzyloxyresorufin O-dealkylase (BROD) 4.5- and 1.1-fold, CYP3A-associated erythromycin N-demethylase (END) 1.4- and 3.3-fold, CYP1A1-associated ethoxyresorufin O-deethylase (EROD) 5.5- and 2.8-fold, and CYP1A2-associated methoxyresorufin O-demethylase (MROD) 3.7- and 1.3-fold. Furthermore, the pattern of induction of CYP immunoreactive proteins by ASP paralleled that of 4-NHP-, PROD-, BROD-, END-, EROD- and MROD-related activities only in the cerebellum. Conversely, no differences in CYP concentration and activity were detected in hepatic microsomes of treated animals with respect to the controls, suggesting a brain-specific response to ASP treatment.

Efecto de la deficiencia de proteínas sobre la peroxidación de lípidos en cerebro de ratas / efect of protein deficiency on lipid peroxidation in brain of rats

El objetivo del presente trabajo es evaluar la formación de radicales libres así como la peroxidación de lípidos en cerebro de ratas machos de la cepa Wistar, de 51 días de edad con diferente condición nutricional, en un diseño factorial 1 x 2, alimentadas ad libitum. Un grupo de ratas fue alimentado con una dieta normal (23 por ciento de proteína), y otro grupo con una dieta normo-calórica hipoprotéica (7 por ciento de proteína), durante 30 días. Semanalmente se midió el nivel de glutatión oxidado en sangre, y al final del experimento se determinó la peroxidación de lípidos en cerebro, mediante la cuantificación de las sustancias reactivas al ácido tiobarbitúrico (TBARS). Los resultados presentaron diferencias estadísticamente significativas, en los niveles de glutatión oxidado en sangre y de TBARS en cerebro, entre los grupos con diferente dieta (p<0.05). Por lo que se sugiere, que existe una relación cualitativa en las alteraciones bioquímicas de los animales del estudio.