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World J Gastroenterol. Apr 14, 2008; 14(14): 2241-2245
Published online Apr 14, 2008. doi: 10.3748/wjg.14.2241
Effects of simulated carbon dioxide and helium peumoperitoneum on proliferation and apoptosis of gastric cancer cells
Ying-Xue Hao, Hua Zhong, Chao Zhang, Dong-Zu Zeng, Yan Shi, Bo Tang, Pei-Wu Yu
Ying-Xue Hao, Chao Zhang, Dong-Zu Zeng, Yan Shi, Bo Tang, Pei-Wu Yu, Department of General Surgery and Center of Minimal Invasive Gastrointestinal Surgery, Southwest Hospital, Third Military Medical University, Chongqing 400038, China
Hua Zhong, Department of Ultrasonography, Southwest Hospital, Third Military Medical University, Chongqing 400038, China
Author contributions: Hao YX, Zhong H, Yu PW and Zhang C designed the research; Hao YX, Zhong H, Zeng DZ, Shi Y and Tang B performed the research; Hao YX and Zhong H analyzed data; Hao YX wrote the paper.
Correspondence to: Pei-Wu Yu, Professor, Department of General Surgery and Center of Minimal Invasive Gastrointestinal Surgery, Southwest Hospital, Third Military Medical University, Gaotanyan Street, Shapingba District, Chongqing 400038, China. yupeiwu01@vip.sina.com.cn
Telephone: +86-23-68754161
Fax: +86-23-68754167
Received: December 18, 2007
Revised: February 5, 2008
Published online: April 14, 2008
Abstract

AIM: To investigate the effects of carbon dioxide (CO2) and helium insufflation administered at different pressures on the growth and apoptosis of cultured human gastric cancer cells.

METHODS: The gastric cancer cells MKN-45 were exposed to a CO2 and helium environment maintained at different pressures (0, 5, 10 and 15 mmHg). The cells were exposed to simulated pneumoperitoneum environment for 4 h, and pH of the culture media was measured after it was moved to normal conditions for 0, 2, 4, 6 and 8 h. Proliferation viability of MKN-45 was examined by 3-[4,5Dimethylthiazol-2-yl],5-diphenyltetrazolium bromide or triazolyl blue (MTT) assay after it was moved to normal conditions. Apoptotic ratio was measured by Annexin V-FITC/PI double labelled staining.

RESULTS: The pH of media was acid and recovered to normal after 4 h in the CO2 group while it was basic in the helium group. There was no difference between CO2 groups (under 10 mmHg ) and control group (P > 0.05) in the proliferative viability of the cells. The cultured cells exposed to 15 mmHg CO2 environment grew more slowly than control group from 4 to 7 d (P < 0.01 ) while there was no difference from 1 to 3 d (P > 0.05). The proliferative viability in helium group was not obviously different from the control group (P > 0.05). The apoptotic ratio of the cultured cells was markedly higher than that of the control group (P < 0.01) at 10 and 15 mmHg CO2 insufflation pressure. In helium group, the apoptotic ratio was not obviously different from the control group (P > 0.05).

CONCLUSION: There is no obvious effect in the proliferation and apoptosis of MKN-45 cells under 10 mmHg CO2 insufflation pressure and helium in any pressure. Fifteen mmHg CO2 insufflation pressure can inhibit the proliferation of the cells and improve apoptosis.

Keywords: Pneumoperitoneum; Gastric cancer cells; Proliferation; Apoptosis