PURPOSE: We compared changes in the populations of peritoneal T lymphocytes and natural killer (NK) cells after CO(2) pneumoperitoneum and laparotomy to clarify whether pneumoperitoneum affects cell-mediated immune responses in the peritoneal cavity. METHODS: We analyzed and compared populations of T lymphocytes and NK cells among peritoneal exudative cells (PECs) collected from 185 female mice subjected to pneumoperitoneum, laparotomy, or anesthesia only. PECs were collected postoperatively, and the populations of T lymphocytes and NK cell subsets were analyzed by flow cytometry. The NK cell cytotoxicity (NKCC) of PECs and splenocytes was measured. RESULTS: The populations of CD3(+), CD4(+), and CD8(+) lymphocytes in the PECs continued to increase up until postoperative day (POD) 7 after laparotomy. The CD4/8 ratio on POD 3 was significantly lower after laparotomy than after pneumoperitoneum. The percentages of NK cells in the pneumoperitoneum group were significantly lower than those in the laparotomy group. On POD 1, the NKCC of splenocytes was less impaired in the pneumoperitoneum group than in the laparotomy group (10.3% vs 5.0%, P << 0.05). CONCLUSION: Laparoscopic surgery is preferable to open surgery because it results in less impairment of systemic and intraperitoneal cell-mediated immune responses.
PURPOSE: We compared changes in the populations of peritoneal T lymphocytes and natural killer (NK) cells after CO(2) pneumoperitoneum and laparotomy to clarify whether pneumoperitoneum affects cell-mediated immune responses in the peritoneal cavity. METHODS: We analyzed and compared populations of T lymphocytes and NK cells among peritoneal exudative cells (PECs) collected from 185 female mice subjected to pneumoperitoneum, laparotomy, or anesthesia only. PECs were collected postoperatively, and the populations of T lymphocytes and NK cell subsets were analyzed by flow cytometry. The NK cell cytotoxicity (NKCC) of PECs and splenocytes was measured. RESULTS: The populations of CD3(+), CD4(+), and CD8(+) lymphocytes in the PECs continued to increase up until postoperative day (POD) 7 after laparotomy. The CD4/8 ratio on POD 3 was significantly lower after laparotomy than after pneumoperitoneum. The percentages of NK cells in the pneumoperitoneum group were significantly lower than those in the laparotomy group. On POD 1, the NKCC of splenocytes was less impaired in the pneumoperitoneum group than in the laparotomy group (10.3% vs 5.0%, P << 0.05). CONCLUSION: Laparoscopic surgery is preferable to open surgery because it results in less impairment of systemic and intraperitoneal cell-mediated immune responses.