T 2 of endotoxin lung injury with and without methylprednisolone treatment

NMR relaxation times ( T 1 and T 2 ) and the water content (WC) of in vitro rat lungs were measured during the course of endotoxin lung injury in rats. Measurements of normal lungs, untreated endotoxin‐injured lungs, and endotoxin‐injured lungs treated with methylprednisolone (MPSL) were compared. The untreated endotoxin lungs showed prolongation of the fast and slow T 2 components ( T 2r and T 2s ), but no significant changes in T 1 or water content. Also, there was no correlation between 1 /WC and relaxation rates or between T 1 and T 2 . MPSL treatment prevented T 2f and T 2s prolongation; however, the duration of MPSL effectiveness was limited. Animals which were treated with MPSL more than 7 h prior to measurements showed T 2 prolongation. This study indicates that NMR relaxation times, particularly T 2 , can be useful in evaluating lung injuries and their treatments. © 1990 Academic Press, Inc.