Rats received inhalation exposure to trichloroethylene (TriCE) or tetrachloro-ethylene (TetraCE) at concentrations of 200, 400 and 800 ppm for a month. Effects of the exposure on free amino acid content of midbrain were investigated by high-performance liquid chromatography. (1) A component on the chromatogram which contains glutamine, threonine and serine was greatly increased by the exposure to TetraCE in a concentration-dependent manner. By TriCE, it was significantly in-creased at 800 ppm. (2) Glutamate showed a tendency to decrease after the exposure to TetraCE. TriCE at 800 ppm significantly decreased glutamate content. (3) TriCE at 400 ppm significantly increased glycine content. (4) TetraCE decreased GABA, but on the contrary TriCE increased it. Both changes were not large and statis-tically not significant. (5) Both TetrCE and TriCE caused no significant change in taurine, aspartate and alanine contents. Exposure of rats to TetraCE and TriCE produced increase in some inhibitory putative neurotransmitter substances and decrease in some excitatory ones.
The present study reports on the pathological exaggeration of liver and kidney in addition to some biological, haematological parameters in copper poisoned rats, Rattus rattus albino. Physical examination of copper treated rats revealed a change in the colour of paws (from pink to white). Retarded animal growth further indicates adverse effects on its health. Haemoglobin percentage and haematocrit value were also decreased, whereas a slight elevation was noticed in the number of WBCs. Necrosis was the important lesion noticed in the liver and kidney. Present findings also show the sites of copper retention in these two tissues.
Plasma and red blood cells were prepared from rats given daily subcutaneous injection of 0.5 mg Cd/kg body weight for 26 weeks. The plasma and hemolysate of the cells were separated by Sephadex G-75 gel filtration. Main cadmium-con-taining (metallothionein) fractions were collected and subjected to DEAE Sephadex A-25 chromatography. DEAE Sephadex A-25 chromatographic profile of the cadmium-containing frac-tion from the plasma showed four cadmium peaks having corresponding copper peaks, but no zinc. DEAE Sephadex A-25 chromatogram of the sample from the hemolysate showed also four cadmium peaks corresponding to the four peaks from the plasma; each peak had an absorption peak at 250 nm. A small amount of zinc was observed at every peak. The separation profiles of two main cadmium peaks of the anion exchange chromatograms from the plasma and hemolysate were consistent with those of two forms of cadmium-induced hepatic and renal metallothionein. These results indicate that the low molecular-weight metal-binding proteins in the blood include metallothionein as a main component and strongly suggest that the proteins affect the turnover of zinc and copper as well as cadmium in the blood.
As an experimental model of dose-response relationship in contact sensitivity with simple chemicals, maneb, which has been known to be a strong sensitizer, was chosen and its modalities of sensitization in the guinea pig was investigated. As a result, dose-dependent relationship between induction and sensitization response was apparently indicated by intradermal injection as well as topical ap-plication technique. The skin reactivity was also corresponded with a range of concentrations used for challenge, but too low challenge concentrations represented a failure to respond despite the fact that the animals were indeed sensitized. A regression line was calculated and about a linear relationship between the induction dose and the incidence of sensitization was obtained from the semilogarithmic graph. The importance of topical induction area and repetitive application in contact sensitivity was also examined and discussed.
An electrobalance equipped with a hang down assembly was used to calibrate a permeation rate of vinyl chloride in a permeation tube and a diffusion rate of organic solvent in a diffusion tube. The permeation rate obtained by the electro-balance coincided fairly with that measured by means of a chemical balance. Gas chromatographic analysis of organic solvent vapor in the dynamic mixture prepared by the diffusion tube technique showed that diffusion rate obtained by the elec-trobalance was practically close to that obtained by the gas chromatography. Calculated diffusion rate was also in good coincidence with the value observed by the electrobalance. Several advantages were presented to calibrate the permeation tube and the diffusion tube by the electrobalance.