Efeitos de diferentes doses de -conotoxina MVIIC no tratamento de ratos submetidos ao trauma medular agudo compressivo

Abstract

The purpose of this study was to evaluate the effect of different doses of MVIIC on experimental acute spinal cord injury (ASCI). Therefore, 36 male Wistar rats were equally distributed into six groups: CTN (negative control group), PLA (positive control group) and those which received doses of MVIIC of 15 (G15), 30 (G30), 60 (G60) e 120 pmol (G120). All groups, except for CTN, were submitted to ASCI with a weight of 70,5 g, during five minutes. Ten minutes later, PLA received intralesional injection of sterile water and G15, G30, G60 e G120 equivalent volume of MVIIC with specific dose. The animals were evaluated by BBB test, blood profile, renal and liver enzymes and urinalysis. After euthanasia, different tissue samples were collected. To evaluate the spinal cord integrity were performed TUNEL and immunohistochemical staining with anti-NeuN antibody. The trauma groups showed severe paraplegia and urinary retention with hemorrhagic cystitis. Doses used were safe as hematological, biochemical liver enzymes and renal and urinary values. However, G120 had a renal deleterious effect. G15 reduced the bladder injury, showed neuronal bodies preservation and was similar to CTN as apoptotic cells in the cranial segment (p <0.05), with no side effects. Therefore, suggests that MVIIC at a dose of 15 pmol provide a protective effect on bladder and on spinal cord of rats submitted to acute spinal cord trauma.