Survival of spermatogonial stem cells in the mouse after exposure to 1.0- MeV fast neutrons

Book · Mon Jan 01 04:00:00 EST 1973

OSTI ID:4341690

de Ruiter-Bootsma, A L; Kramer, M F; de Rooij, D G; Davids, J A.G.

The surviving number of stem cells after irradiation was estimated by determining the fraction of repopulated tubules in crosssections of the testis, 11 weeks after irradiation. This fraction, called the repopulation index, is assumed to be directly proportional to the number of surviving stem cells. Groups of mice were irradiated with different doses of 1-MeV fast neutrons ranging from 200 to 410 rads. Within this dose-range the dose-response curve has an exponential slope with a D/sub 0/ of 85 rads. This value indicates the rather low radiosensitivity of spermatogonial stem cells, compared with differentiated spermatogonia and stem cells of other tissues. Two other groups of mice received doses of 900 and 1,200 rats of x rays, in order to determine the RBE of the fast neutrons used. A RBE value of 4.4 was found. The response of spermatogonial stem cells to a dose of 350 rads of fast neutrons, divided into two fractions, was studied using fractionation intervals varying between 0 to 48 hours. At all intervals repopulation indices were lower than in controls, irradiated without fractionation. The radiosensitivity of the stem cells increases sharply between 4 and 8 hours after the first irradiation. Hence, in contrast to the behavior of stem cells in other tissues investigated, spermatogonial stem cells surviving an irradiation get into a state or phase of greater radiosensitivity. (GE)

• Research Organization: Rijksuniversiteit, Utrecht
• NSA Number: NSA-29-016017
• OSTI ID: 4341690
• Country of Publication: Germany
• Language: English

Related Subjects

*FAST NEUTRONS-- RBE
*FRACTIONATED IRRADIATION-- RADIOSENSITIVITY EFFECTS
*RADIOSENSITIVITY-- FRACTIONATED IRRADIATION
*SPERMATOGONIA-- RADIOSENSITIVITY
BIOLOGICAL RADIATION EFFECTS
BIOLOGICAL REGENERATION
DOSE- RESPONSE RELATIONSHIPS
MEV RANGE 01-10
MICE
N48520* --Life Sciences--Radiation Effects on Animals-- Vertebrates
PHOTON BEAMS
STEM CELLS
SURVIVAL TIME
TESTES
X RADIATION