The effects of inhibiting leukocyte migration with fucoidin in a rat peritonitis model

Objectives: To study the effects of fucoidin on leukocyte rolling and emigr ation and bacterial colonization in a peritonitis sepsis model in rats. Design and interventions: A controlled study in 64 male Wistar rats, anesth etized and rendered septic by cecal ligation and puncture (CLP). Immediatel y after CLP 32 animals received a continuous infusion of fucoidin and 32 a continuous infusion of Ringer's lactate. Measurements and main results: Systemic leukocyte counts were determined ev ery 2 h after CLP. Surviving animals were anesthetized 24 h after CLP, and intravital measurements of leukocyte rolling in venules in the cremaster mu scle were performed. The animals were then killed and their organs harveste d for histological and microbiological examinations. The 24-h survival was comparable in the two groups. Fucoidin-treated animals had higher leukocyte counts in the systemic circulation and lower counts in the lungs, liver, a bdominal cavity, and brain than control animals. The number of bacterial co lony forming units in the abdominal cavity, lungs, liver, brain and blood d id not differ in the two groups. Fucoidin-treatment changed the type of bac teria predominantly found in the examined organs from Escherichia coli to P seudomonas aeruginosa. Conclusions: In an intra-abdominal model of sepsis we found that treatment with fucoidin induces leukocytosis inhibits leukocyte rolling and reduces l eukocyte emigration in the abdominal cavity, lungs, and liver. Reduction in the number of emigrating leukocytes was not associated with an increase in bacterial counts found in the examined organs.