Cadmium이 흰쥐의 carbonic anhydrase 활성에 미치는 영향과 보상효고에 관한 연구

Abstract

This incidence of clinically identifiable cadmiosis, both acute and chronic, has been increased due to expansion of industrial production and utilization of cadmium.

Fuck et al., (1971) speculated that the cadmium may function in or may be an etiological factor for various pathological processes, namely, testicular tumor, renal dysfunction, hypertension, arteriosclerosis, bony decalcification, chronic

diseases of old ages and cancer, Mechanism f toxic effect of cadmium is not exactly known. Recently, a several investigators(Hodgen et al., 1969; Gunn, 1961 a) asserted that the cadmium exerts to bind metallo-enzymes, such as carbonic

anhydrase, and it may inhibit enzyme activities. The present study is to confirm the mechanism of cadmium toxicity, whether various pathological changes or diseases are caused by direct inhibition of carbonic anhydrase in rats.

It is also to find out preventive measures for the toxic effect of cadmium upon carbonic anhydrase activity.

A total of one hundred healthy albino rats were selected for the experiments and divided into five groups as follows:

Ⅰ. Controls.

Ⅱ. 0.12mg cadmium chloride injection.

Ⅲ. 1.20mg cadmium chloride injection.

Ⅳ. 1.20mg each of cadmium chloride & zinc acetate injection.

Ⅴ. 1.20mg each of cadmium chloride & chromium oxide injection.

After the intra-peritoneal injection of experimental chemicals, the rats were sacrificed at the intervals of 24 hours and 48 hours. Then, blood, liver, kidney and testis were obtained for the experiments. Cadmium contents and carbonic anhydrase activities in blood, liver, kidney and testis were determined.

Histological changes in the tissues were also observed.

The results obtained were as follow:

1. The contents of cadmium in the kidney and the testis in male rats wer increased by time lapse, whereas those in the blood and the liver were decreased.

2. In the tissues of male rats, zinc and chromium prevented accumulation of cadmium.

3. In the both sexes of rats in vitro, the inhibition of carbonic anhydrase activities was not observed.

4. Cadmium inhibited carbonic anhydrase activities in all of the tissues of male rats in vivo.

5. There was no prominent pathological changes in the liver and the kidney except in the testis.

6. Cadmium toxicity on carbonic anhydrase was not seen in the female rats.

7. In the male rats, zinc and chromium prevented cadmium inhibition on carbonic anhydrase activities in tissues examined in vivo.

From the above results, damage to the tissues by cadmium is considered to be the results of inhibition of carbonic anhydrase activity, especially in the testis of the male rats. Carbonic anhydrase inhibition by cadmium may be prevented by zinc and chromium, resulting in the absence of testicular damage.