Stretch-induced nerve injury: a proposed technique for the study of nerve regeneration and evaluation of the influence of gabapentin on this model

The rat models currently employed for studies of nerve regeneration present distinct disadvantages. We propose a new technique of stretch-induced nerve injury, used here to evaluate the influence of gabapentin (GBP) on nerve regeneration. Male Wistar rats (300 g; n=36) underwent surgery and exposure of the median nerve in the right forelimbs, either with or without nerve injury. The technique was performed using distal and proximal clamps separated by a distance of 2 cm and a sliding distance of 3 mm. The nerve was compressed and stretched for 5 s until the bands of Fontana disappeared. The animals were evaluated in relation to functional, biochemical and histological parameters. Stretching of the median nerve led to complete loss of motor function up to 12 days after the lesion (P<0.001), compared to non-injured nerves, as assessed in the grasping test. Grasping force in the nerve-injured animals did not return to control values up to 30 days after surgery (P<0.05). Nerve injury also caused an increase in the time of sensory recovery, as well as in the electrical and mechanical stimulation tests. Treatment of the animals with GBP promoted an improvement in the morphometric analysis of median nerve cross-sections compared with the operated vehicle group, as observed in the area of myelinated fibers or connective tissue (P<0.001), in the density of myelinated fibers/mm2 (P<0.05) and in the degeneration fragments (P<0.01). Stretch-induced nerve injury seems to be a simple and relevant model for evaluating nerve regeneration.

Atividade antinociceptiva do extrato etanólico do fruto de Solanum acanthodes Hook.f. em camundongos

Solallum acanthodes. popularmente conhecido como "jurubeba", foi estudada com o objetivo de avaliar suas propriedades antinocicept i vas nos modelos de nociccpção induzida pela I'ormalina e glutamato. Para isto foi utilizado o extrato elanólico dos frutos (EES) da planta. Os resultados apresentaram altos níveis de significância, demonstrando o potencial analgésico de S. acanthodes.

Solanum acanthodes, popularly known as "jurubcba", was studied with the objective to evaluatc its antinocíccptivc propcrties In lhe models aI' fonnalin-induced nociceptive and glutamate. For this lhe cthanolic extract of lhe fruits (E.ES) of the plant was used. The results had prescnlcd high lcvcls 01' significance, demonstrating lhe analgesic potcntial of S. acanthodes.