Effect of angiotensin II on cord blood CD34+ cells expansion in vitro.

In order to investigate the influence of angiotensin II on hematopoietic system, CD34+ cells in cord blood were purified, and the effects of angiotensin II in combination with various cytokines on their growth and differentiation were studied by cell culture in vitro. It was found that angiotensin II in suspending medium could stimulate both BFU-E and CFU-GM expansion. The number of BFU-E and CFU-GM was increased with the increases of angiotensin II concentrations during a certain range. In addition, the expansion fold of CFU-GM was increased from 2.3 +/- 0.8 times to 7.8 +/- 2.3 times when angiotensin II was added in the presence of SCF+G-CSF+GM-CSF+IL3 cytokines mixture. Similarly, the expansion fold of BFU-E was increased from 3.1 +/- 1.8 times to 9. 2 +/- 2.3 times with angiotensin II in the presence of SCF+EPO+TPO+IL-3. In the semi-solid medium, angiotensin II could stimulate CFU-GM expansion but had no effect on the growth of BFU-E. In conclusion, angiotensin II had some stimulating effects on cord blood hematopoietic progenitors expansion in vitro in the presence of other cytokines.