EFFECT OF GAMMA IRRADIATION ON SERUM ISOENZYME SYSTEMS

The objective of this program was to study serum LDH isoenzyme alterations after subacute irradiation with primates. These alterations were to be related to dose in order to relate the minimum dose necessary to produce significant LDH isoenzyme changes. The doses studied were 200, 300, and 500 rads at a dose rate of 20 rads/min. Blood was collected, and the clear supernatent was analyzed by electrophoresis and histochemical staining for LDH isoenzymes. The isoenzyme change and the altered ratio were calculated and related to dose of irradiation received. It has been established that the band 1-to-band 2 ratio should be 1.0-to-2.5. Values above or below this range are considered abnormal. Depression of the 1-to-2 ratio that lasted 72 hr was seen at 4 hr after irradiation in the 300- and the 500-rad groups. The ratio became markedly elevated to 4.2-to-1 in the 300-rad group at 168 hr. This elevation was not seen in the 200-rad group, whose ratio remained depressed throughout the test period. It appears that 200 rads is not the lower limit of radiation detected by serum LDH isoenzyme alterations but that lower levels may be detectable with these methods. (Author)