Biphasic edema development after experimental brain contusion in rat.
The time course of edema development following experimental brain contusion was studied by measuring cortex specific gravity 1 and 12 h after the trauma, and thereafter once daily until 7 days after the trauma. A biphasic development of edema was observed; the specific gravity decreased to a minimum on day 2 (P < 0.001), increased to an almost normal level on day 4 and thereafter decreased again to a second minimum 6 days after the trauma (P < 0.01). Delayed edema formation has been recognized in clinical settings, but has not been described in experimental studies. This study, with a prolonged daily follow-up, clearly demonstrates that a secondary phase of edema is an experimentally reproducible entity. The model will enable study of the pathogenetic mechanisms.
D000818:Animals; D001929:Brain Edema / Q000503:physiopathology*; D001930:Brain Injuries / Q000503:physiopathology*; D003288:Contusions; D005260:Female; D006112:Gravitation; D007249:Inflammation; D051381:Rats; D017207:Rats, Sprague-Dawley; D013997:Time Factors