Sensitivity of porcine peripheral blood leukocytes to gamma irradiation in vivo, in vitro and ex vivo

Abstract

Purpose: The large white pig is a useful experimental model to compare in vivo, in vitro and ex vivo sensitivity of peripheral blood leukocytes to ionising radiation. Such studies are impossible to perform in humans and laboratory rodents due to ethical reasons and body size, respectively. We analysed dose- and time-dependent changes of lymphocyte and granulocyte absolute numbers in porcine peripheral blood after either whole-body irradiation (in vivo and ex vivo experiments) or exposure of porcine whole blood to γ-irradiation (in vitro experiments).

Materials and methods: CytoCount™ absolute counting beads and light scatter analysis using a flow cytometer were used to determine major leukocyte subpopulation numbers in blood samples after red cell removal.

Results: Similar to other species, lymphocyte numbers significantly decreased in pigs both in vivo and in vitro in a dose-dependent manner. Most importantly, our data clearly show that reduction of lymphocyte numbers after irradiation in vivo proceeds much faster than after irradiation in vitro and that granulocyte changes depend only on the time of analysis after irradiation.

Conclusions: All three tested experimental arrangements demonstrated the radiosensitivity of lymphocytes and the radioresistance of peripheral blood granulocytes. These in vivo and in vitro approaches, as well as the newly introduced ex vivo observations, appear to be relevant to biodosimetry.

Keywords:

• ionising radiation
• absolute cell count
• flow cytometry
• peripheral blood
• pig

Acknowledgements

We would like to gratefully acknowledge Iveta Tothova for excellent technical assistance in all projects. This work was supported by the Ministry of Defence of the Czech Republic (Grant nos. MO0FVZ0000501 and OPUOFVZ 200809) and by the Ministry of Education, Youth and Sports of the Czech Republic (Grant no. 2B08028).

Declaration of interest: The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper.