Apoptosis in rat peripheral lymphocytes in vitro and vivo following low level gamma irradiation

摘要

Apoptosis, also called programmed cell death, is a critical event in the embryogenesis and development of multicellular organisms. It is morphologically and biochemically characterized by cytoplasmic granularity, cell shrinkage, chromatin condensation, fragmentation of DNA by endonuclease, membrane blebbing and apoptotic body[1]. Enzymatic cleavage of DNA is now used by many investigators as a biochemical hallmark of apoptosis. Apoptosis occurs in number of physiological process, senescence of neutrophil and T cell clone maturation, etc. A little has been known of intracellular effectors that related to apoptotic process. Possible signalling mechanisms include influx of calcium and altered or different expression of ICE, Fas, foS c-myc and bcl-2 gene[2]. Inhibition and induction of apoptotic process may be crucial for cell differentiation and tumorogenesis. Mature lymphocytes readily undergo spontaneous apoptosis in vitro[3].