PROFILATIC TREATMENT WITH FOLIC ACID FOR LOWER LIMB ISCHAEMIA-REPERFUSION INJURY IN AGED RATS

INTRODUCTION Lower limb ischemia-reperfusion injury (IRI-LL) is a common major complication in orthopaedic surgery, especially in elderly patients. We previously demonstrated that folic acid reduced IRI-LL damage in 3–4-month-old rats. Current work analyses the effect of folic acid in the prevention of IRI-LL in elderly animals. MATERIAL AND METHODS Thirty-six 12-month-old male WAG/RijHsd rats were subjected to 3 hours of ischaemia. Eighteen animals received folic acid (2.5 mg/kg, ip) 20 minutes before the end of ischaemia period; the other half received the same volume of saline. Animals were sacrificed after 3 hours, 24 hours, and 14 days of reperfusion for biochemical (tissue damage markers and electrolytes), histopathological studies of gastrocnemius muscle, and daily assessment of limb function by Rotarod test, respectively. RESULTS The administration of folic acid prior to the end of ischaemia period reduced by 30-40% the increase in LDH and CK observed in non-treated animals (p < 0.0001). When histological sections were analysed, folic acid was found to reduce by 20% the number of damaged muscle fibbers per field (60±17.1 vs 80.7±16.4, p < 0.0001). Rotarod test revealed that folic acid also led to an improvement in muscle function, assessed by the time the animals spend running on the rod, when comparing to untreated animals. CONCLUSIONS The administration of folic acid, prior to the end of ischemic period, decreases the damaged induced by IRI-LL, also achieving a faster recovery of mobility.