Definitions for radiosensitivity
This page provides all possible meanings and translations of the word radiosensitivity
Random House Webster's College Dictionary
ra•di•o•sen•si•tiveˌreɪ di oʊˈsɛn sɪ tɪv(adj.)
(of certain tissues or organisms) sensitive to or destructible by various types of radiant energy, as x-rays.
Origin of radiosensitive:
sensitivity to the action of radiant energy
The relative sensitivity of cells or organisms to any form of radiation, but especially to the harmful effects of ionizing radiation
Radiosensitivity is the relative susceptibility of cells, tissues, organs or organisms to the harmful effect of ionizing radiation. Cells are least sensitive when in the S phase, then the G1 phase, then G2 phase and the most sensitive in the M phase of the cell cycle. This is described by the law of Bergonié and Tribondeau, formulated in 1906: X-rays are more effective on cells which have a greater reproductive activity. From their observation, they concluded that quickly dividing tumor cells are generally more sensitive than the majority of body cells. This is not always true. Tumor cells can be hypoxic and therefore less sensitive to X-rays that mediate most of their effects through free radicals produced by ionizing oxygen. Later it has been shown that the most sensitive cells are those that are undifferentiated, well nourished, divide quickly and are highly metabolically active. Amongst the body cells, the most sensitive are spermatogonia and erythroblasts, epidermal stem cells, gastrointestinal stem cells. The least sensitive are nerve cells and muscle fibers. Very sensitive cells are also oocytes and lymphocytes, although they are resting cells and do not meet the criteria described above. The reasons for their sensitivity are not clear.
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