Neurochemical changes pentoxifylline in the temporal cortex of rats submitted to model temporal lobe epilepsy induced by pilocarpine

R.M.P. Siqueira1, A.L.C. Cavalcante2, T.M. Olinda1, D.O. Gonçalves1, I.B.F. Calou1, G.S. Cerqueira1, K.R.T. Neves1, F.A.V. Lima1, S.B. Bezerra3, R.S.N. Pinho3, G.S.B. Viana1. 1Federal University of Ceara, Physiology and Pharmacology 60430-270, Brazil, 2Federal University of Ceara, Medicine 60430-140, Brazil, 3Federal University of Ceara, Pharmacy 60430-170, Brazil

Objective: To assess the neurochemical effects of administration of pentoxifylline in animal model of temporal lobe epilepsy induced by pilocarpine.

Methods: We used male Wistar rats (200-250g, n=6), divided into four groups N (animals treated with saline), P400 (animals treated with pilocarpine 400 mg/Kg i.p.), PTX25 and PTX50 (animals pretreated with pentoxifylline 25 e 50 mg/Kg p.o.) after one hour treated with pilocarpine 400 mg/Kg i.p. (groups: P400, PTX25 and PTX50) or saline i.p. (group: N) and after three hours of induced seizures, the animals were decapitated and their brains dissected. The striatum was removed and the homogenate prepared in 10% perchloric acid to 1%. For this dosing device was used for high performance liquid chromatography (HPLC). Before administering the standard sample was applied in micro concentration of 2.5 µM (aspartate, glutamate, glycine, taurine, and GABA). Statistical analysis by ANOVA followed by Student-Newman-Keuls test with p <0.05.

Results: The levels of aspartate increased in the P400 group (18.09 ± 2.020 µmol/g tissue) compared to N group (10.00 ± 1.02 µmol/g of tissue) and reduced in PTX25 and PTX50 (7.85 ± 1.77 and 8.18 ± 1.35 µmol/g of tissue) when compared to P400. Glutamate levels were higher in group P400 (9.44 ± 0.72 µmol/g of tissue) compared with the group N (4.09 ± 0.29 µmol/g of tissue) and decreased by PTX25 and PTX50 (2.06 ± 0.21 and 3.85 ± 0.54 µmol/g of tissue) when compared to P400. Glycine levels were elevated in P400 (23.93 ± 2.09 µmol/g of tissue) compared with the group N (15.07 ± 2.18 µmol/g of tissue) and decreased in groups and PTX25 PTX50 (7,29 ± 0.61 and ± 1.23 8.2 µmol/g tissue) compared to the N and P400. Taurine levels increased by P400 (6.67 ± 0.66 µmol/g tissue) compared with group N (4.79 ± 0.71 µmol/g of tissue) and reduced in PTX25 and PTX50 (3.54 4.16 ± 0.50 and ± 0.21 µmol/g of tissue) compared to the group P400. GABA levels increased in PTX50 (11.44 ± 0.82 µmol/g tissue) compared to the P400 group (8.93 ± 1.31 µmol/g of tissue) with no significant differences between both groups.

CONCLUSION: Pentoxifylline proven to changes in levels of inhibitory and excitatory amino acids in the temporal cortex of rats submitted to pilocarpine-induced seizure. These changes are significant for understanding the neuroprotective activity of pentoxifylline in this seizure model.