Inbred F344 rats as a biologic model of intra-abdominal sepsis

RESUMO

Aiming to design a biologic model of acute intra-abdominal sepsis for experimental studies, conventional, isogenic rats F344 were infected with the bacteria Escherichia coli (E.coli), strain 11775, serotype H701K1. Six hours after inoculation with E. coli, the animals - males and females - showed the following symptoms piloerection, hyperpnea and decreased motor activity. The lethal dosis (LD50), was 6 x 10(5) CFU/ml, analyzed in 32 males and 32 females. The highest mortality rate was observed on the first 24 hours. Liver dysfunction, common in intra-abdominal sepsis, was evaluated at 0, 24, 48 and 168 hours after inoculation, by means of serum enzyme activities. Study of the migration of polymorphonuclear-neutrophil cells (PMN) and mononuclear-macrophage ones (MN) showed a significant increase of PMN in E. coli inoculated males (z > 4.7; P<0.003) and females (z > 6.2; P < 0.0003), when compared to control groups. As for MN cells, there were no differences between inoculated and control groups, in males (z = 2.3; P = 0.0107) and in females (z = 1.8; P = 0.0359) as well. In conclusion, these results show that inbred F344 rats are adequate biologic models for studies of acute, intra-abdominal sepsis