21-AMINOSTEROID U-74389F REDUCES VASOGENIC BRAIN EDEMA

21-Aminosteroids have been shown to attenuate neuronal damage and to i mprove neurological outcome after experimental ischemia. The aim of th is study was to determine whether brain edema induced by a cryogenic i njury can be influenced by the 21-aminosteroid U-74389F. A cortical fr eezing lesion was applied to the right parietal region of Sprague-Dawl ey rats under ketamine-xylazine anesthesia. Systemic blood pressure wa s monitored in the peritraumatic period. Four different doses of U-743 89F (A-D) were studied for their effect on post-traumatic brain swelli ng and edema. Respective control groups received only the solvent, cit ric acid buffer. (A) 3 mg/kg b.w. i.p. (total dose) 30 min before, 1 a nd 12 h; post trauma (p.t.); (B) 9 mg/kg b.w. i.v. 30 min before, 1 an d 12 h p.t.; (C) 25 mg/kg b.w. i.v. 30 min before, 1, 6, and 12 h p.t. ; (D) 50 mg/kg b.w. i.v. 15 min before, 15 and 30 min as well as 1, 2, 6, and 12 h p.t. 24 h after trauma, brains were removed and hemispheri c swelling and water content were determined from the difference betwe en wet and dry weight. Application of the 21-aminosteroid U-74389F mod erately reduced post-traumatic brain swelling in all treatment groups: (A) 5%, (B) 9%, (C) 12%, and (D) 14%. In parallel with this, the incr ease in water content of the traumatized hemisphere was marginally low ered by U-74389F in all groups; in (C) e.g. from 1.9 +/- 0.1% to 1.7 /- 0.1%, p = 0.07. These two findings taken together indicate that the 21-aminosteroid U-74389F moderately reduces post-traumatic swelling a nd edema.