Neuroprotective Effects of Milrinone on Acute Traumatic Brain Injury

BACKGROUND: Traumatic brain injury is still an important health problem worldwide. Traumatic brain injury not only causes direct mechanical damage to the brain but also induces biochemical changes that lead to secondary nerve cell loss. In this study, we investigated the neuroprotective effect of milrinone after traumatic brain injury (TBI) in a rat model. METHODS: Forty male Wistar albino rats, were used. Rats were divided into 4 groups: 1) sham, 2) TBI, 3) TBI + Ringers, and 4) TBI + Milrinone. In group 1 (sham), only craniotomy was performed. In group 2 (TBI), TBI was performed after craniotomy. In group 3 (TBI + Ringer), TBI was performed after craniotomy and intraperitoneal Ringers solution was given immediately afterward. Group 4 (TBI + Milrinone), TBI was performed after craniotomy, and milrinone was given 1.0 mg/kg milrinone intraperito-neally directly (0.5 mg/kg milrinone intraperitoneally again 24 hours, 48 hours, and 72 hours after trauma). Tests were performed for neurological and neurobehavioral functions. Immunohistochemistry and histopathology studies were performed. RESULTS: In group 4 compared with group 2 and group 3 groups, tests for neurological functions and neuro-behavioral functions were significantly better. In the mil-rinone treatment used in group 4, plasma and brain tissue tumor necrosis factor, 8-OH 2-deoxyguanosine , and inter-leukin 6 levels were significantly decreased, and increased plasma and tissue IL-10 levels were detected. Histopathological spinal cord injury and apoptotic index increased in groups 2 and 3, while significantly decreasing in group 4. CONCLUSIONS: This study shows for the first time that the anti-inflammatory, antioxidant and antiapoptotic prop-erties of milrinone may be neuroprotective after TBI.