Correlation between leptin and pro-inflammatory cytokines in cortical contusion injury model.

BACKGROUND The present study aimed to investigate time-dependent changes in leptin concentrations in brain tissue following experimental traumatic brain injury and to examine the relationship with cytokines. METHODS After circular craniectomy, 33 male Wistar-albino rats were positioned on a stereotaxic frame and subjected to cortical contusion injury and then divided into 3 groups based on the depth of deformation as: 0 mm (sham controls, n=3), 1.5 mm (moderate injury, n=15) and 2.7 mm (severe injury, n=15). Animals were sacrificed on the 1st, 3rd and 5th days post-injury. RESULTS One day after moderate injury, interleukin-1 beta (IL-1 beta), IL-6, tumor necrosis factor-alpha (TNF-alpha), and leptin levels were found to be markedly increased in the brain tissue. On the 3rd and 5th days, the levels returned to the sham-control levels. Following severe injury, IL-1 beta, IL-6 and TNF-alpha levels increased in correlation after the 1st day and reached the sham-control levels on the same days. However, leptin tissue levels decreased on the 1st and 3rd days and normalized to the sham-control levels on the 5th day. CONCLUSION Our results showed that the release of leptin is decreased in the early stage of severe injury. Thus, leptin replacement may play an important role in therapy in cases with severe traumatic brain injury.