THE INFLUENCE OF THE TRACE METALS UPON THE ACONITASE ACTIVITY IN HUMAN PROSTATE GLANDS

Abstract

The concentration of zinc (Zn²⁺) and copper (Cu²⁺) were measured with a polarography in diseased human prostate glands, and the contents of iron (Fe²⁺) in the normal and hyperplastic prostate glands was also estimated spectrometrically.
The influences of Zn²⁺, Cu²⁺, Fe²⁺ and the other trace metals on the aconitase activity of the human prostate were studied.
The results obtained were as follows.
1. The mean value of Zn²⁺ contents was 458.2±128.7μg per gm. of dry tissue in the normal prostate glands, 2258.4±170.5μg in the hyperplastic prostate glands and 458.7±157.1μg in the cancerous prostate glands, and the mean value of Cu²⁺ contents was 11.9±3.1μg per gm. of dry tissue in the normal prostate glands, 10.5±2.9μg in the hyperplastic prostate glands and 10.9±3.7μg in the cancerous prostate glands.
2. The mean value of Fe²⁺ contents was 5.7±0.12μg per gm. of wet tissue in the normal prostate glands, and 5.9±0.37μg in the hyperplastic prostate glands.
3. Compared with the normal and cancerous prostate glands, high Zn²⁺ value was found in the hyperplastic prostate glands, but the contents of Cu²⁺ and Fe²⁺ in the hyperplastic prostate glands were not different from that of the normal and cancerous prostate glands.
4. With both biochemical and histochemical procedures, the aconitase activity in the hyperplastic prostate gland was demonstrated to be markedly inhibited by the addition of 10^-4-10^-2M concentration of Zn²⁺ and Cu²⁺, and being activated by the addition of 10^-4M concentration of Fe²⁺.
Aconitase activity was unchanged in the presence of other trace metals, such as barium, cobalt, magnesium, manganese and lead.
From the above mentioned findings, it was concluded that Zn²⁺ might be regarded as an inhibitor of the aconitase activity of the hyperplastic prostate glands.