ANTI-INFLAMMATORY EFFECTS OF LOCALLY VERSUS SYSTEMIC INJECTED MORPHINE ON CHEMICALLY INDUCED INFLAMMATION: AN EXPERIMENTAL ANIMAL STUDY

The current role of opioids in medical practice focuses on their well-known analgesic effect, but recently different studies were aimed to analyse their potential anti-inflammatory effect at both local and systemic levels.Our experimental animal study was aimed to determine the effects of different concentrations of morphine injected either locally or intraperitoneally on chemically inflamed paw volumes.Male Wistar rats were randomly assigned to six groups and injected with a single intraplantar injection of carrageenan 1% and subsequently another injection with either normal saline or morphine according to their group.Measurements with a plethysmometer were taken at 0, 6, 24, 48 and 72 hours after the first injection.Our experiment shows a statistically significant decrease in paw volume of rats injected with 5mg/kg of intraplantar morphine sulphate, thus demonstrating a local anti-inflammatory effect of high-dose morphine.These data provide evidence that opioids do have a role in inflammation and suggest that they could play a therapeutic role in anti-inflammatory treatment. RezumatRolul actual al opioidelor n practica medical se concentreaz pe bine cunoscutul lor efect analgezic, dar studii recente au avut ca scop analiza potenialului lor efect antiinflamator att la nivel local, ct i la nivel sistemic.Studiul nostru experimental pe animale de laborator a avut ca scop determinarea efectelor diferitelor doze de morfin injectate local -intraplantar, respectiv intraperitoneal asupra volumului lbuelor cu edem inflamator produs prin injectarea local de caragenin.obolanii masculi Wistar au fost repartizai aleatoriu n ase grupuri.Tuturor le-a fost administrat intraplantar n lbua posterioar dreapt 0,15 ml soluie de caragenin 1%, pentru inducerea inflamaiei i ulterior o a doua injectare cu soluie salin intraplantar sau intraperitoneal (grupul martor) sau cu morfin intraplantar sau intraperitoneal (grupurile testate).Msurtorile au fost efectuate cu un pletismometru Ugo Basile 7140 la 0, 6, 24, 48 i 72 de ore dup prima administrare.Experimentul arat o scdere semnificativ statistic a volumului lbuei obolanilor injectai cu 5 mg/kg de sulfat de morfin intraplantar, demonstrnd astfel un efect antiinflamator local al morfinei n doze mari.