Avaliação nociceptiva em ratos com obesidade induzida por glutamato monossódio frente ao exercício físico

Abstract

The aim of this study was to evaluate the nociceptive responses of animals treated with monosodium glutamate (MSG) and the effects produced by chronic physical exercise [21-60 days of life (Group I) or 60-90 days of life (Group II)]. The nociceptive responses were tested after 60 days of life (Group I) as well as 90 days of life (Group II) in all groups of rats using Von Frey, hot plate and tail flick. In the conclusion of the experiment, the rats were sacrificed and the adiposity in animals treated with MSG was evidenced after to weigh epididimal and intercostal fat. The results were presented as mean ±standard error of the mean and subjected to two-way analysis of variance (ANOVA) followed by Newman Kells. When assessing the mechanic stimulation by Von Frey method it is possible to observe: Group I MSG sedentary animals showed a higher resistance when compared with animals of sedentary control ( 17,258 ± 1,302 g vs 31,132 ± 1, 829 g). MSG animals submitted to physician exercises had recovered the nociceptive function when compared with the MSG sedentary (31,957± 0,972 g vs 17,258± 1,302 g ). In the group II it is possible to notice a partial recuperation of the nociceptive activity of MSG trained animals when compared with MSG sedentary animals (22,128± 1,186 g vs 16,287±1,205g ) but this partial recuperation is explained because the control sedentary animals presents 29,043 ± 1,423 g) p< 0,01. The MSG sedentary rats present higher latency response in the tail flick test: Group I (18.240± 1.915 s vs 8.535± 2.316 s) and Group II(16,930± 1,848 s vs 9,532± 2,442 s ). Hot plate: Group I (18.240± 1.915 s vs 8.535± 2.316 s), Group II(16,930± 1,848 s vs 9,532± 2,442s) when compared with control sedentary animals. However, latency has returned to the normal levels only in the MSG trained rats of group I: tail flick (12,490± 1,405 s), hot plate (9,603± 1,410s). The results have demonstrated that the MSG`s administration can modify the nociceptive responses and part of this responses are recover.