Cafeteria diet administered from lactation to adulthood promotes a change in risperidone sensitivity on anxiety, locomotion, memory, and social interaction of Wistar rats.

PURPOSE: To evaluate the nutritional status and behavior of animals fed a cafeteria diet from the onset of lactation after the addition of risperidone. METHODS: During the lactation period, 14 litters of Wistar rats (dam + 8 pups) were fed one of two diets: control (CTRL; n = 7) or cafeteria (CAF; n = 7). After weaning, the males were placed in individual cages, receiving the same diet as offered to their respective dams. Food and caloric intake, body weight, feed and energy efficiency, and adipose tissue weight were evaluated in the male offspring. In adulthood, they were assigned to receive treatment with saline (CTRL-S, CAF-S) or risperidone (CTRL-R, CAF-R) (n = 21 in each group). They then underwent behavioral testing, which included the elevated plus maze, open field, object recognition, and social interaction tests. Variance analysis (ANOVA) was used, followed by Newman-Keuls when p-values were < 0.05. RESULTS: The CAF group exhibited higher caloric intake, weight gain, feed efficiency, and adipose tissue than the CTRL group. The animals in the CAF group exhibited oxidative stress characteristics in the hippocampus, which may have compromised the function of this structure and promoted behavioral changes. The CAF-S group exhibited anxiety, as indicated by the greater number of entrances and time spent in the center of the open field. They also showed greater locomotion through a greater number of quadrants traveled. CAF-S animals also demonstrated memory impairments, assessed using the object recognition test, and decreased social interaction. The CAF-R group demonstrated anxiety and decreased locomotion in the open field. There was a decrease in their interaction with both objects in the object recognition test. The CAF-R group obtained greater sociability in the social interaction test. Such effects may be associated with changes in the serotonergic system of these animals. CONCLUSION: Risperidone administered to animals on a cafeteria diet led to a greater reduction in locomotion, had an anxiogenic effect, caused impaired memory, and improved social interaction.

Simultaneous determination of ethionamide and pyrazinamide using poly(l-cysteine) film-modified glassy carbon electrode.

A selective, simple and rapid square wave voltammetry method, based on electropolymerization of l-cysteine (poly(l-Cys)) on a glassy carbon electrode (GCE), was developed in this study for simultaneous determination of ethionamide and pyrazinamide. Electroanalytical and electrochemical properties of the poly(l-Cys)/GCE were investigated by cyclic voltammetry (CV), square wave voltammetry (SWV), electrochemical impedance spectroscopy (EIS) and scanning electrochemical microscopy (SECM). The cyclic voltammetry studies revealed an remarkable electrocatalytic activity of poly(l-Cys)/GCE on ethionamide and pyrazinamide at pH 1.0. The best potential separation between the reduction peaks of the drugs in a mixed solution was found to be 0.14V. It was also found that pyrazinamide exhibits a reversible wave with Epc and Epa at -404mV and -347mV (versus EAg/AgCl), respectively, while ethionamide presents an irreversible reduction peak at Epc=-536mV. The optimized calibration curves for simultaneous determination of ethionamide and pyrazinamide exhibited good and high linear responses within the concentration range 2.38-248.0µmolL(-1) and 0.476-51.2µmolL(-1), respectively. The limit of detection was found to be 0.531µmolL(-1) for ethionamide and 0.113µmolL(-1) for pyrazinamide. The poly(l-Cys)/GCE-based square wave voltammetry method was successfully used to determine ethionamide and pyrazinamide in human urine and blood serum.

Development of a sensor for L-Dopa based on Co(DMG)(2)ClPy/multi-walled carbon nanotubes composite immobilized on basal plane pyrolytic graphite electrode.

L-Dopa is the immediate precursor of the neurotransmitter dopamine, being the most widely prescribed drug in the treatment of Parkinson's disease. A sensitive and selective method is presented for the voltammetric determination of L-Dopa in pharmaceutical formulations using a basal plane pyrolytic graphite (BPPG) electrode modified with chloro(pyridine)bis(dimethylglyoximato)cobalt(III) (Co(DMG)(2)ClPy) absorbed in a multi-walled carbon nanotube (MWCNT). Scanning Electron Microscopy and Fourier Transform Infrared Spectroscopy were used to characterize the materials. The electrocatalytical oxidation of L-Dopa using the Co(DMG)(2)ClPy/MWCNT/BPPG electrode was investigated by cyclic voltammetry and square wave voltammetry. The parameters that influence the electrode response (the amount of Co(DMG)(2)ClPy and of MWCNT, buffer solution, buffer concentration, buffer pH, frequency and potential pulse amplitude) were investigated. Voltammetric peak currents showed a linear response for L-Dopa concentration in the range of 3 to 100 µM, with a sensitivity of 4.43 µAcm(-2)/µM and a detection limit of 0.86 µM. The related standard deviation for 10 determinations of 50 µM L-Dopa was 1.6%. The results obtained for L-Dopa determination in pharmaceutical formulations (tablets) were in agreement with the compared official method. The sensor was successfully applied for L-Dopa selective determination in pharmaceutical formulations.