Effect of radiation on fin regeneration of the fish, Oryzias latipes, with special reference to dose-rate.

Abstract

Inhibitory effects of raddiation on the regeneration of fin of the fish, Oryzias latipes, irradiated before fin amputation was examined. Both whole body and local irradiation of the fin region alone suppressed the elongation of fin and prevent cell differentiation into fin rays dependent on the given dose. The earlier processes of the regeneration, wound healing and blastema formation, were relatively resistant to radiation. Reduction in the dose-rate resulted in a sparing effect on the radiation damage. In spite of the serious inhibition of the fin regeneration resulted from acute (250 R/min) irradiation of 4 kR, irradiation performed at exposure-rate reduced to 25 R/min or less did not prevent fin regeneration at least in the examination of the fin elongation.