Abstract
1. A method for histochemical demonstration of aconitase was presented based on OCHOA's indirect method using isocitric dehydrogenase and TPN combined with nitro-BT reduction.
2. The incubation medium was composed of 4ml of 0.2M sodium cis-aconitate, 10ml of 0.05M veronal buffer (pH 7.4), 2ml of 0.005M manganese chloride. 5mg of TPN, 10mg of nitro-BT, and 4ml of distilled water.
3. The liver, kidney, small intestine and brain of the rat, and the prostate of man and dog were investigated with this method. Strong activity was demonstrated in the hepatic cells of the peripheral part of the hepatic lobules, in the epithelial cells of the proximal convoluted tubules of the kidney, and glandular cells of the prostate.
4. The method is examined with respect to the specificity of enzyme activity concerned by adding or omitting substrates, cofactors, activators and inhibitors to or from the mixture. It is clear that the method demonstrates aconitase with coexistent isocitric dehydrogenase and TPN-diaphorase. DPN-linked isocitric dehydrogenase might not be concerned in this method.
