Avaliação da Participação do Receptor 5-HT 3 na Modulação da Analgesia Induzida pela TENS Evaluation of Receptor 5HT3 In the Modulation of Analgesia Induced by TENS

Objective. Verify the participation of the serotoninergic pathway and the 5HT3 receptor in modulation of TENS induced analgesia. Method. Male wistar rats were used weighing from 180 to 200g, which were pretreated with ondansetron (OND) 3mg/kg and physiologic saline before the therapy with TENS which lasted 30 minutes. Right after the end of the electric stimulation, the nociceptive thresholds were evaluated up to 60 minutes. Results. We observed that the serotoninergic pathway and the 5HT3 receptors take part at the modulation of the TENS induced analgesia, once the OND administration antagonized the antinotiception of TENS in both high and low frequency (p<0,05). We also analyzed that high frequency TENS provided a stronger analgesia which also lasted longer than low frequency TENS. Conclusion. We can conclude that the serotoninergic pathway and the 5HT3 receptors are involved in the modulation of TENS induced analgesia.