GENETIC EFFECT OF CHRONIC EXPOSURES OF MALE-MICE TO GAMMA-RAYS

  • 1 January 1985
    • journal article
    • research article
    • Vol. 21  (2) , 245-251
Abstract
The frequency of reciprocal translocations (RT) in mouse spermatogonia induced by .gamma.-rays at doses of 1.5-4.5 Gy [Gray] and dose rates of 2.7 .times. 10-6, 5.8 .times. 10-6, 9.4 .times. 10-5 and 4.5 Gy/min was studied. A linear increase was observed in the RT frequency with increasing the dose, at all dose rates. At 9.4 .times. 10-5 Gy/min the RT frequency was, on average, 10 times lower, as compared to that for a single single acute dose rate of 4.5 Gy/min. Further reduction of the dose rate did not result in a decrease of the RT yield, and at the lowest dose rate of 2.7 .times. 10-6 Gy/min (the dose being 3.0 Gy) the RT frequency was higher than using the same dose at dose rates of 5.8 .times. 10-6 and 9.4 .times. 10-5 Gy/min. Possible reasons for an increase in the RT frequency at low dose rates are considered. A study of the frequency of abnormal sperm heads (ASH) has shown that at the dose rate of 9.4 .times. 10-5 Gy/min it is independent of an accumulated dose and is equal to the value obtained when exposing to an acute dose of 3.0 Gy. At dose rates of 2.7 .times. 10-6 and 5.8 .times. 10-6 Gy/min ASH frequencies were only slightly increased at all doses, as compared to the control level.