OXIDATIVE ENZYMES

I. SUCCINIC DEHYDROGENASE, DPN CYTOCHROME C REDUCTASE, CYTOCHROME OXIDASE, AND CATALASE IN ORAL, LIVER, AND BRAIN CORTEX TISSUES

¹ Departments of Experimental Dentistry and Pathology, USAF School of Aviation Medicine, Randolph Air Force Base, Texas

1. Total protein, succinic dehydrogenase, DPN cytochrome c reductase, cytochrome oxidase, and catalase have been determined in submaxillary gland, tooth pulp, gingiva, tongue mucosa, liver, and brain cortex tissue homogenates of normal female rabbits.

2. Total protein was quantitated in terms of gamma of protein per 0.1 ml. of a 1:50 dilution of homogenate. Enzyme concentrations were expressed as unit activities, the enzyme velocity constant per milligram of protein.

3. Comparisons were made between each tissue to establish the relative concentrations for each component analyzed, assigning a value of 100 per cent to the liver.

4. The liver and submaxillary gland possessed equally high levels of total protein. Tongue mucosa, brain cortex, gingiva and tooth pulp, respectively, gave lower total protein values; the brain cortex and gingiva being approximately equal.

5. The liver, submaxillary gland, and brain cortex possessed high succinic dehydrogenase, DPN cytochrome c reductase, and cytochrome oxidase unit activities. The tongue mucosa yielded intermediate activities for these enzymes; whereas, relatively low activities were uniformly detected in the tooth pulp and gingiva.

6. For catalase, the liver yielded the highest unit enzyme activity. Gingiva, tooth pulp, and submaxillary gland exhibited considerably lower unit activity. The brain cortex possessed the smallest activity.