The effect of inflammation on the generation of plasma DNA from dead and dying cells in the peritoneum

Abstract: To assess the effects of inflammation on the generation of circulating DNA from dead and dying cells, plasma DNA levels were determined in BALB/c mice, administered apoptotic or necrotic Jurkat cells following induction of peritonitis by treatment with thioglycollate (TG), peptone (PT), or sodium periodate (NaIO4). In mice receiving TG or NaIO4, plasma DNA levels following intraperi-toneal administration of Jurkat cells were signifi-cantly reduced compared with controls, whereas they were not affected in mice receiving PT. To determine the basis of these differences, the cellu-lar composition of peritoneal fluids prior to the administration of the dead cells was analyzed. Among agents tested, TG administration led to the largest increase in cells—neutrophils and mono-cytes. As shown by flow cytometry, the exudates contained apoptotic neutrophils and macrophages, with the highest levels in the TG-induced exudates. Analysis of DNA and caspase 3 in the fluids also showed differences; TG exudates showed increases in DNA and capase 3; and NaIO4-induced exudates had an increase only in DNA. Fluid from PT-treated mice did not have increases in DNA or caspase 3. Together, these results indicate that prior inflammation can affect the generation of blood DNA from apoptotic or necrotic cells, al-though this effect may vary depending on the com-position of the exudates with respect to cells as wel