Abstract: Objective To explore the mortality rate and changes in splenic cell cycle and apoptosis in rats with abdominal infection. Methods An animal model of sepsis was induced by cecal ligation and puncture (CLP) in rats. At serial time points 0 h, 6 h, 12 h, 24 h, 48 h, and 72 h after CLP, the animal death rate was calculated. The percentage of cell cycle G1, S, G2/M phase and apoptosis of isolated spleen cells were analyzed using flow cytometer. The expression of p27 of spleen tissue was determined by Western blot analysis. Results In the rat model of CLP-induced systemic inflammatory response, the mortality of animals gradually increased at 0 h, 6 h, 12 h, 24 h, 48 h and 72 h after CLP surgery, reaching a maximum of 88.81%. The abdominal infection in the animals gradually worsened at 0 h, 6 h, 12 h, and 24 h after CLP surgery, but localized and gradually alleviated after 48 h and 72 h. Within 48 h after CLP surgery, there was a blockage in the G1 phase of the spleen cell cycle, an increase in the percentage of apoptotic cells, and an elevation in p27 expression. After 48 h, the G1 phase blockage gradually recovered, the number of apoptotic cell decreased, and p27 expression declined. Additionally, within 48 h after CLP surgery, there was a decrease in the percentage of cells in the S and G2/M phases of the spleen cell cycle, but the percentage of cells in these phases gradually increased after 48 h. ConclusionsCell cycle arrest and apoptosis of the spleen cells are potentially contributed to the change of animal mortality after abdominal infection.

Key words: spleen, severe sepsis, cell cycle, apoptosis, p27