ENZYMATIC AND HISTOCHEMICAL STUDIES ON THE ACTION OF IONIZING RADIATIONS IN ANIMAL EXPERIMENTS. I. INVESTIGATION OF SERUM AND TISSUE ENZYMES IN WHOLE-BODY IRRADIATED RATS WITH PARTIAL PROTECTION OF THE INTESTINE (in German)
An enzyme of the glycolytic series, lactic dehydrogenase (LDH), and one of the tricarboxylic acid cycle, malic dehydrogenase (MDH), which have been previously shown to undergo changes in tissue destruction and regeneration, were assayed in the serum and tissues of irradiated rats. The rats were exposed to 800-r doses of 200-kv x rays; in some animals a 2 x 2 cm lead shield was placed over the abdomen in the duodenal region during irradiation, and in others an intestinal loop was exteriorized surgically and shielded during exposure. Enzyme assays were made in serum and homogenates of skin, liver, spleen, and intestine at 1, 3, 5, 10, 12, and 30 days postirradiation. In unshielded rats, serum LDH activity rose 2-fold, from a control level of 13 units to a max of 26 units on the first day, then declined to normal by the 5th day. With intestinal shielding a max on the 3rd day of 22 units was seen. In intestine of unshielded rats, LDH fell markedly, from 283 to 7 units on the 3rd day; then it rose to a max of 940 units on the 12th day. A similar biphasic, but much less pronounced change (min 83, max 450 units) was noted. Serum MDH activity rose markedly in the unprotected rats, from 120 to a max of 680 units on the 5th day; whereas after intestinal shielding the max was lower (184 units) and earlier 3rd day). Without shielding, MDH activity in intestine fell from 8094 to 422 units on the 3rd day, then rose to 45818 units on the 10th day. Shielding raised the min (4321 units, 3rd day) and lowered the max (27501 units, 12th day). These biphasic changes in enzyme activities reflect the destructive and regenerative processes following irradiation, and show that even partial protection of the intestine ameliorates these changes. Moreover, 90% of the shielded animals survived 30 days or longer compared to only 50% of the unprotected rats. (BBB)
- Research Organization:
- Universitat, Heidelberg
- NSA Number:
- NSA-17-038761
- OSTI ID:
- 4629052
- Journal Information:
- Aerztliche Forschung (West Germany) Discontinued, Journal Name: Aerztliche Forschung (West Germany) Discontinued Vol. Vol: 16; ISSN ARZFA
- Country of Publication:
- Country unknown/Code not available
- Language:
- German
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