thromboxane-a2 and hydrocortisone-acetate

Within 24 hours after a full-thickness burn injury, predictable alterations occur in the dermal vasculature. At the immediate site of injury, vessels lose patency. In the periphery, vasodilation and increased permeability become widespread. A variety of interventions were employed to prevent these vascular sequelae. While systemic treatment, immediately after burn trauma, with hydrocortisone or the non-steroidal anti-inflammatory compound indomethacin, was ineffective in preventing vascular alteration, treatments with other NSAI agents such as ibuprofen and imidazole were effective in preventing microvascular occlusion. In addition, utilizing standard radioimmunoassay techniques, the concentrations of the metabolites of two potent eicosanoids, thromboxane and prostacyclin, were measured from fluid collected in the implanted wound chambers. Following full-thickness burns, the synthesis and release of thromboxane were inhibited by indomethacin, imidazole, and ibuprofen. Furthermore, indomethacin and ibuprofen, but not imidazole, blocked the synthesis and release of prostacyclin into wound fluid. Significantly, ibuprofen was effective in preserving the dermal vasculature, even when administration was delayed as long as 6 hours after burn trauma. Pharmacologic actions not associated with the production of thromboxane or prostacyclin appear responsible for the protective effects of ibuprofen during burn injury. Such findings do not support an important role for either thromboxane or prostacyclin in the development of vascular alterations following burn injury.

Topics: Animals; Anti-Inflammatory Agents; Blood Coagulation; Burns; Epoprostenol; Hydrocortisone; Ibuprofen; Imidazoles; Ischemia; Male; Rats; Rats, Inbred Strains; Skin; Thromboxane A2; Time Factors; Vasodilation