Enzymatic Activity of Radiated Exteriorized Salivary Glands

¹ From the Naval Medical Research Institute, National Naval Medical Center, Bethesda, Maryland

It was previously determined that when salivary glands of rats were radiated in situ with 3–5000 r of 200-kv x-ray there was a significant increase in specific activity of the glucose-6-phosphate and isocitric dehydrogenases. At the same time it was observed that there were other more general effects from this localized radiation. The present study was designed to determine what effect radiation (2000 r) would have upon the enzyme systems of exteriorized salivary glands of rats under conditions wherein the rest of the animal was completely shielded. Under these conditions we observed no general effects upon the animals and even the weights of the radiated salivary glands were not significantly altered, whereas in the previous study this was not the case. The values for glucose-6-phosphate dehydrogenase were higher for radiated salivary glands in 17 out of 18 groups of animals, the average values in arbitrary units being 3.36 ± 0.71 for the nonradiated glands and 3.83 ± 0.67 for the radiated glands when all groups of rats were considered (probability 0.05). During the 2nd week following radiation, the increase in activity of this enzyme was greater, the values being 3.04 ± 0.48 and 3.80 ± 0.42, respectively (probability 0.01). There was not a significant change in isocitric dehydrogenase following radiation of the exteriorized salivary glands.