Objective: To perform an experimental model of Multiple Organ Dysfunction Syndrome (MODS) without employing bacteria or endotoxin stimulus and to follow its evolution in vivo by a Computerized Tomography analysis of the lungs.
Design: Rats were submitted to intraperitoneal injection of a 2.5% zymosan suspension in mineral oil (1 g/kg weight) or mineral oil alone; control rats received no treatment.
Methods: The observation period was 15 days. During this period symptoms and survival were noticed daily. CT scans of lungs were made at the 7th and 14th days; data were post-processed to obtain information on lung density. The rats were sacrificed at the 15th day by heart puncture; blood was utilized for determination of hemochrome, differential leukocyte count, thrombocytes, glycemia, uremia, bilirubin. Lungs, liver, spleen and kidney were dissected and weighted for determination of relative organ weight.
Data analysis: Data were compared by "t" Student's test for impaired data and Fisher Exact test.
Results: Symptoms, survival, blood analysis and relative organ weight agreed with a progressive, ingravescent, triphasic illness caused by a systemic inflammatory response involving remote organ too. The CT study proved able to monitoring and analyzing organ damage: a temporal sequence of evolution of damage exists; organ damage is localized in microcirculatory system (density augment) and in parenchyma (morphologic alterations and fibrosis).
Discussion: The described experimental model reproduces a MODS-like illness in zymosan receiving rats; the CT scan is effective to evaluate the evolution of organ damage.