Effect of acute administration of methylphenidate on brain metabolism in striatum of adult rats.
Streck, E.L.1; Fagundes, A.O.N.1; Rezin, G.T.1; Zanette, F.1; Dal-Pizzol, F.2; Quevedo, J.3
(1)Laboratório de Bioquímica Experimental, UNESC – (2)Laboratório de Fisiopatologia Experimental, UNESC – (3)Laboratório de Neurociências, UNESC.
Objectives: Methylphenidate (MPH) is frequently prescribed for the treatment of attention deficit/hyperactivity disorder. Psychostimulants can cause long-lasting neurochemical and behavioral adaptations. However, the exacts mechanisms underlying its therapeutic and adverse effects are still not well understood. In this work, our objective was to investigate brain metabolism in striatum of adult rats submitted to acute MPH administration.
Methods and Results: We evaluated the activity of mitochondrial respiratory chain complexes II and IV and succinate dehydrogenase (Clin Chim Acta 1985, 153:23; Clin Chim Acta 1994, 228:35) in striatum of adult rats after acute MPH administration. 60-day-old rats received a single injection of MPH s.c. (1, 2, 5, 10 and 20 mg/kg) or saline (controls) (Neuroreport 2002, 14:769). After 1 h, the animals were sacrificed and striatum was isolated. Our results showed that MPH significantly activated the complexes II (Saline: 8.1±1.9, 1 mg/kg: 8.6±1.0, 2 mg/kg: 9.3±1.5, 5 mg/kg: 10.5±2.1, 10 mg/kg: 10.4±1.7, 20 mg/kg: 8.1±1.5, p<0.05, n=5) and IV (Saline: 155.8±27.7, 1 mg/kg: 199.7±15.3, 2 mg/kg: 189.4±25.0, 5 mg/kg: 176.7±20.0, 10 mg/kg: 194.4±12.6, 20 mg/kg: 199.5±8.3, p<0.05, n=5) and inhibited succinate dehydrogenase (Saline: 27.2±4.0, 1 mg/kg: 22.3±2.8, 2 mg/kg: 20.3±3.2, 5 mg/kg: 17.6±5.0, 10 mg/kg: 12.5±2.7, 20 mg/kg: 11.9±3.5, p<0.05, n=5).
Conclusions: Our findings demonstrated that MPH altered brain metabolism in striatum of rats. These results may help us to better understand neurochemical effects of MPH and highlight the need for further research to improve understanding of its effects on central nervous system.
Financial Support: CNPq and UNESC.
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