Abstract

EFFECTS OF DIFFERENT PRESSURES OF CO2 ON P33 TUMOR INHIBITOR GENE IN LIVER AND SPLEEN TISSUES DURING CO2 PNEUMOPERITONEUM IN ADULT RATS

Somayeh Fallahnezhad, Ali rostami and Iraj Jafari Anarkooli*

ABSTRACT

Aims: This study aimed to investigate the effect of different pressures of CO2 on expression of P33 gene and apoptosis in liver and spleen cells during CO2 pneumoperitoneum. Methods: In this study, 30 male Sprague-Dawley rats, weighing approximately 280-340 grams were procured from Tehran Pasteur Institute’s animal house, and randomly divided into 3 equal groups. Groups 1 and 2 received 10 and 20 mmHg respectively, and group 3 was the control group. CO2 was insufflated into abdominal cavity of rats in groups 1 and 2 for one hour using a cannula, and then, perfusion was performed for half an hour. In group 3, cannula was placed into abdominal cavity without releasing any gas. The rats were sacrificed afterwards, and their livers and spleens were removed after laparotomy to investigate expression of gene P33 and apoptosis using RT-PCR and TUNEL techniques. Results: The TUNEL technique showed a significant increase in apoptosis in liver cells of rats that received 20 mmHg compared to rats that received 10 mmHg and control group (P<0.0001). Similarly, the increase in apoptosis in spleen cells was also significant in rats that received 20 mmHg compared to rats in 10mmHg and control groups (P<0.006). Furthermore, RT-PCR revealed a significant decrease in P33 gene mRNA in liver and spleen cells in 20 mmHg group compared to other two groups (P<0.001). Conclusion: Pressure level and duration of use of Co2 gas affect viability of liver and spleen cells. Too high a pressure or too long a duration may cause release of cytokines and free-radicals from cells of these organs, which can lead to transient or serious dysfunction.

Keywords: CO2 pneumoperitoneum, apoptosis, P33, liver, spleen.