Effects Of TCA On Apoptosis Of Immunocytes In Mice

Taurocholic acid (TCA) is one of the main effective components of cattle and sheep bile, also it's main active constituent which play pharmacological action. In the paper, to clarify the effects of TCA on apoptosis of immunocyte in mice, the effects of TCA on priming phase, executing phase, biochemistry characteristic phase of apoptosis of thymocyte and the biochemistry characteristic phase of apoptosis of peritoneal macrophage, lymphocyte in peripheral blood and spleen were examined. The effect of TCA on percentage of phosphatidylserine eversion of thymocyte was determined using flow cytometry. The results showed that high dose TCA significantly decreased the phosphatidylserine eversion of thymocyte, inhibited the apoptosis of thymocyte. The results of experiment in vitro showed that both the three different dose of TCA remarkably decreased the phosphatidylserine eversion, inhibited the apoptosis of thymocyte. The effects of TCA on activation of Caspase-9 and Caspase-3 during apoptosis of thymocyte were detected by spectrophotometric method. TCA remarkably increased the activity of Caspase-9, induced the apoptosis of thymocyte in vivo. In addition, middle and high dose of TCA also increased the activity of Caspase-9 significantly, induced the apoptosis of thymocyte in vitro; Low dose of TCA remarkably increased the activity of Caspase-3, induced the apoptosis of thymocyte in vivo, but middle dose of TCA increased the activity of Caspase-9 significantly, induced the apoptosis of thymocyte in vitro. The effects of TCA on apoptosis percentage of immunocytes of mice were determined by diphenylamine method, the results showed that low and high dose of TCA induced the apoptosis of thymocytes noticeably, low dose of TCA induced the apoptosis of peritoneal macrophage, induced the apoptosis of peripheral blood lymphocyte at high and low dose. But TCA inhibited the apoptosis of splenic lymphocytes significantly at high and low dose. Conclusion: TCA can remarkably decrease the phosphatidylserine eversion of thymocyte; can remarkably increase the expression of Caspase-9 and Caspase-3 in thymocyte, had promotional effects on apoptosis at priming phase and execute phase. TCA can increase the percentage of DNA fragmentation of thymocyte, peritoneal macrophage and peripheral blood lymphocyte in mice, promote the apoptosis of immunocyte; TCA can decrease the percentage of DNA fragmentation of splenic lymphocyte in mice, depress the apoptosis of splenic lymphocyte, inhibit the apoptosis of splenic lymphocyte.