Radiation-Induced Apoptosis of Lymphocytes in Peripheral Blood.
- Author:
Yoon Kyeong OH
1
;
Tae Bum LEE
;
Taek Keun NAM
;
Keun Hong KEE
;
Cheol Hee CHOI
Author Information
1. Department of Therapeutic Radiology, Chosun University Medical School, Gwangju, Korea. ykoh@chosun.ac.kr
- Publication Type:In Vitro ; Original Article
- Keywords:
Lymphocyte;
Blood;
Radiation;
Apoptosis
- MeSH:
Apoptosis*;
DNA Fragmentation;
Female;
Flow Cytometry;
Healthy Volunteers;
Heparin;
Humans;
Lymphocytes*;
Male;
Microscopy, Electron;
Particle Accelerators
- From:The Journal of the Korean Society for Therapeutic Radiology and Oncology
2003;21(1):75-81
- CountryRepublic of Korea
- Language:Korean
-
Abstract:
PURPOSE: This study quantitatively evaluated the apoptosis in human peripheral blood lymphocytes using flow cytometry, and investigated the possibility of using this method, with a small amount of blood, and the time and dose dependence of radiation-induced apoptosis. MATERIALS AND METHODS: Peripheral blood lymphocytes were isolated from the heparinized venous blood of 11 healthy volunteers, 8 men and 3 women, with each 10 ml of blood being divided into 15 samples. The blood lymphocytes were irradiated using a linear accelerator at a dose rate of 2.4 Gy/min, to deliver doses of 0.5, 1, 2 and 5 Gy. The control samples, and irradiated cells, were maintained in culture medium for 24, 48 and 72 hours following the irradiation. The number of apoptotic cells after the in vitro X-irradiation was measured by flow cytometry after incubation periods of 24, 48 and 72 hours. We also observed the apoptotic cells using a DNA fragmentation assay and electron microscopy. RESULTS: The rate of spontaneous apoptosis increased in relation to the time interval following irradiation (1.761+/-0.161, 3.563+/-0.564, 11.098+/-2.849, at 24, 48, and 72 hours). The apoptotic cells also increased in the samples irradiated with 0.5, 1, 2 and 5 Gy, in a radiation dose and time interval after irradiation manner, with the apoptosis being too great at 72 hours after irradiation. The dose-response curves were characterized by an initial steep increase in the number of apoptotic cells for irradiation doses below 2 Gy, with a flattening of the curves as the dose approached towards 5 Gy. CONCLUSION: The flow cytometric assay technique yielded adequate data, and required less than 1 mL of blood. The time and dose dependence of the radiation-induced apoptosis, was also shown. It is suggested that the adequate time interval required for the evaluation of apoptosis would be 24 to 48 hours after blood sampling.
