Efeitos da nicotina na lesão medular traumática: uma análise ex vivo

Abstract

Nicotine is a psychoactive drug that has deleterious effects. However, there is little literature concerning its effects on spinal tissue. Spinal cord injury (SCI) resulting from spinal lesions that cause changes in sensitivity, motor and autonomic neuronal function, which can lead to irreversible life-changing neurological damage. Nicotine has been linked to increased tissue necrosis, resulting from vasoconstriction and decreased local perfusion. In order to understand this relation, this work investigated the effect of nicotine on spinal tissue after SCI, using the ex-vivo model of spinal tissue from Wistar rats. The tissues were incubated for 3 days, followed by the protocols of nicotine induction (10 mM for 3 days acute exposition), and SCI compression by impact from a height of 25 mm and weight of 0.5 grams in the center of the medullary tissue section and then 14 days of follow-up. Samples of the supernatant were collected at 24h up to 14 days for LDH analysis. By the end of the experiment, MTT tests, nuclear morphology by DAPI and LiveDead cell assays were performed. The tissues that were exposed to nicotine and then suffered SCI had less cell viability and showed higher levels of LDH, when compared to the other groups. Since SCI is a limiting condition and nicotine is a potentially vasoactive substance, it was possible to assess its effects on medullary tissue and verify that both hampered tissue recovery. This study has important implications and encourages the elucidation of the nicotine mechanism in SCI [resumo fornecido pelo autor].