ABSTRACT
BACKGROUND: Repopulation of the mesothelial monolayer after focal exfoliation, having the monolayer in vivo and in situ exposed to dialysis solutions, has not been thoroughly investigated. This study describes repopulation of a 'doughnut' like mesothelial ring exfoliated from the anterior liver surface of rats. METHODS: Animals were divided into 5 groups of 20 rats each. Group 1 - control unexposed animals: mesothelial cell imprints were taken after 1 (5 rats), 5 (5 rats), and 15 (10 rats) days following the procedure of exfoliation. Group 2 - sham injected animals. Group 3 - rats IP injected once a day, during 30 consecutive days with Hank's balanced salt solution. Groups 4 and 5 - same experimental protocol, but injecting 4.25% glucose single bag or 7.5% Icodextrin PDF. Imprints and/or biopsies were taken after a recovery period of 15 days, counted from the last IP injection. RESULTS: Density distribution of mesothelial cells in group 2 was not significantly different from that seen in unexposed rats, whereas that seen in group 3 Hank's balanced salt solution was marginally but significantly lower (p < 0.05) from that seen in controls. Eighty five percent of rats injected with 4.25% glucose developed fibrous adhesions, binding up together the exfoliated liver surface and the diaphragmatic muscle. For Icodextrin treated rats, the prevalence of fibrous adhesions was 95%. CONCLUSIONS: The 'doughnut' experimental model appears as a promising tool for in vivo and in situ investigation of mesothelial repopulation. Both osmotic agents substantially restrain mesothelial repopulation, leading to repair by connective tissue.