Evaluation of protein metabolism of experimental animals during intoxication with cadmium sulfate and its combinations with other poisons

The article presents the results of the study of some indicators of protein metabolism in experimental animals intoxicated with cadmium sulfate and its combination with other poisons, as well as the protective role of sulfate ion. These data indicate that the toxicity of cadmium when isolated is greater than at its effects in combination with other poisons. It has the importance in the diagnosis and prevention.

At present, fairly large workers contingent is exposed to cadmium compounds occupationally, as they are widely used in various industries. Hygienic studies have been conducted in a number of industries, but the alkaline batteries manufacture has attracted great attention of scientists [1, 2]. Since 1920 years, there were descriptions of cases of industrial poisoning by compounds cadmium occurring mainly by inhalation [3].

Cadmium and its compounds are polytropic poisons influencing on many functions and systems of the body. In a number of cases, the toxicological studies have confirmed that changes in health status found in workers are occupationally conditioned and effected by cadmium.

Physiological antagonism of cadmium and some other trace elements occur at the level of absorption. In particular, low zinc concentration (0.01-1 mmol/l ) increases the rate of cadmium absorption in the gut of rats, apparently, due to the induction of biosynthesis of zinc metalotionein. Higher zinc concentrations, on the contrary, hinder the absorption of cadmium. Moreover, in rats the expressed antagonism is mounted on the suction between cadmium and mercury, cadmium and copper [4].

In chicken and mice the inhibition of iron absorption by cadmium and cobalt is demonstrated. In their turn, these poisons reduce the absorption of cadmium that partly can be explained by their protective effect in cadmium poisoning.

In this context, the aim of this study was to investigate the influence of cadmium sulfate and its combination with other poisons on the protein metabolism in experimental animals.

Materials and methods

The studies are performed experimentally, in rabbits of both sexes with an initial weight of 2100-2900. Two series of experiments lasted for 4 months. In each series, there were 3 groups of animals.

Note: The animals received substance orally and daily, except of weekends and holidays.

Monthly, indicators such as DNA and RNA blood, total protein, blood urea were determined by well known methods in animals. Comparative analysis of the protein fractions in the serum in animals orally exposed to cadmium sulfate solution at 0.5 mg/kg and 0.5 mg/kg in combination with other poisons showed that after 1 month of the experiment the administration of the cadmium (0.5 mg/kg), the total protein content did not change in both experimental groups compared with the control, and had no significant difference.

After 2 months, the total protein content was reduced in animals treated by cadmium sulfate with significant difference compared to the control.

After 3 months, no changes in theses indices were shown in the experimental groups compared to control.

After 4 months, the total protein content was increased in the cadmium group with proved difference between them and the control group, i.e. in the sulfate group, there was practically no difference from the control.

Thus, after 4 months of the experiment, if cadmium at 0.5 mg/kg was administered coupled with sulfate, its protective function had place with proven probability.

The administration of cadmium with the poisons mixture had no changes in figures in the experimental groups and no difference was observed between them and control group after 1, 3 and 4 months of the experiment. After 2 months of the experiment, the total protein content was reduced in animals exposed to cadmium with the poisons mixture, with significant difference compared to the control group. The same happen to the group of animals treated by sulphate and the poisons mixture, but the difference between them and the control was not proven, i.e. we can say that a positive influence of sulfate has been there.

Practically no changes found in the urea content in the experimental groups after 1 and 2 months of administration of cadmium (0.5 mg/kg). It was increased in the group exposed to cadmium, by the end of 3 and 4 months of the experiment, with significant difference compared to the control group. In the group of animals additionally treated by sulfate, not significant increase of urea content was observed. Thus, we can propose that the sulfate adjusts the changes caused by cadmium intoxication (0.5 mg/kg).

In animals exposed to cadmium with the poisons mixture the urea rate was increased twice, while in animals treated with additional sulfate, it was almost equal to the control group's rate.

After 2 and 3 months of the experiment, no changes in plasma urea level were observed in the experimental groups. In 4 months, the urea level increased in both experimental groups with significant difference compared to the control indicator, although it should be noted that in the cadmium group, it was higher than in the sulfate group.

The results indicate that the cadmium intoxication (0.5 mg/kg) there were no changes in DNA content in the experimental groups after 1 month of the experiment. After 2 months, this index increased with significant difference in the experimental groups. After 3 and 4 months, the reverse pattern is observed, and the indices were reduced, so the difference between the cadmium and control groups was significant, while between the cadmium and sulfate group no difference was not proved. Thus, in this case, the positive effect of sulfate has occurred.

In animals exposed to cadmium (0.5 mg/kg) with the poison mixture no changes in DNA level were noted in 1 and 2 months of the experiment. In the end of 3 and 4 months of the experiment, this index increased in the cadmium group with reliable degree of difference compared to the control group. In animals treated with sulphate, sulfates were able to prevent changes, so there was no difference compared to the control index.

As seen from the tables, the cadmium exposure (0.5 mg/kg of body weight) has no effect in plasma RNA level by the end of 1 month of the experiment. In the end of 2 months, this index increased significantly in the cadmium group. In animals exposed to additional sulfate, this index slightly increased, with no significant change compared to the control. After 3 and 4 months of the experiment, the index significantly dropped in the cadmium group, while in the sulfate group it practically did not differ from the control. Thus, again the sulfate provided significant positive impact throughout the experiment.

In animals exposed to cadmium (0.5 mg/kg) with the poison mixture, the RNA levels did not changed by the end of 1 and 2 months of the experiment and were within the control. After 3 and 4 months of the experiment, this index increased in the cadmium group with reliable degree of difference to the control group, while in animals treated with sulphate, no changes noted, thus, there was no difference compared to the control group.

From the described above, it follows that the exposure to only cadmium the toxic effect is greater than in combination with other poisons.

REFERENCE

1. Ishhuk I.G. Gigienicheskaja ocenka uslovii truda pri rabotah s okis'ju kadmija i dihlorjetanom v proizvodstve shhelochnyh akkumuljatorov: автореф. дис. ... канд. мед. наук - Алматы, 1971. - 258 с.
2. Mihaleva L.M. Kadmijzavisimaja patologija cheloveka //Arhiv patologii. – 1988. - T. 50. - № 9. – Р. 81-85.
3. A.A. Lukashev Biologicheskaja i gigienicheskaja rol' kadmija i mysh'jaka (jekologicheskie aspekty). - Almaty: 2004. - 326 с.