Journal of Zhejiang University SCIENCE
(ISSN 1009-3095, Monthly)

2005   Vol. 6B   No. 7   p.650-655

Influence of CO₂ pneumoperitoneum on intracellular pH and signal transduction in cancer cells

CAO Li-ping^†1, DING Guo-ping², QUE Ri-sheng¹, ZHENG Shu³

(¹Department of Surgery, Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou 310009, China)
(²Department of Surgery, Ningbo No 2. Hospital, Ningbo 315010, China)
(³Cancer Research Institute, School of Medicine, Zhejiang University, Hangzhou 310009, China)
^†E-mail: cao@zju.edu.cn
Received Feb. 23, 2005; revision accepted May 3, 2005

Abstract: Object: The authors studied the influence of CO₂ pneumoperitoneum on intracellular pH and signal transduction arising from cancer cell multiplication in laparoscopic tumor operation. Method: They set up a simulation of pneumoperitoneum under different CO₂ pressure, and then measured the variation of intracellular pH (pHi) at different time and the activity of protein kinase C (PKC) and protein phosphatase 2a (PP2a) at the end of the pneumoperitoneum. After 1 week, the concentration of cancer cells in the culture medium was calculated. Result: When the pressure of CO₂ pneumoperitoneum was 0, 10, 20, 30 mmHg respectively, the average pHi was 7.273, 7.075, 6.783, 6.693 at the end of the pneumoperitoneum; PKC activity was 159.4, 168.5, 178.0, 181.6 nmol/(g·min) and PP2a was 4158.3, 4066.9, 3984.0, 3878.5 nmol/(g·min) respectively. After 1 week, the cancer cells concentration was 2.15×10⁵, 2.03×10⁵, 2.20×10⁵, 2.18×10⁵ L⁻¹. Conclusion: CO₂ pneumoperitoneum could promote acidosis in cancer cells, inducing the activation of protein kinase C and deactivation of protein phosphatase 2a, but it could not accelerate the mitosis rate of the cancer cells.

Key words: Cancer, CO₂ pneumoperitoneum, Intracellular pH, Signal transduction
doi:10.1631/jzus.2005.B0650             CLC number: R616