It was shown that there was a marked increase in protein synthesis of thymocytes that were metabolically labelled with

3

H-Leu for 4

6

8 and 12 hous in low dose irradiated mice showing 33.26%

51.48%

51.54% and 34.98% increase respectively at different time intervals of incubation when the thymic and splenic cells were sampled 4 hours after whole body irradiation (WBI) with 75 mGy X-rays. The results suggest that there is an increase in protein synthesis with its peak at 6~8 hours after radiation. Changes in protein synthesis of immune cells in mice 4 hours after radiation and incubated for 4~12 h were observed with SDS-PAGE followed by densitometrical scanning. It is revealed that 28 kD protein synthesis was increased gradually within 12 hours of incubation and 43 kD protein synthesis was increased in the thymocytes rapidly reaching a maximum 2 hours after incuba

tion. It was also exhibited that the synthesis of 43 kD protein and 32 kD protein was increased in the splenocytes 2 hours after incubation. These findings may have implications in the mechanism of immunoenhancement and adaptive response induced by low dose radiation.