Dimethylformamide (DMF) has been widely used in the synthetic textile industry as an organic solvent. However, it is known that DMF irritates to skin and mucous membranes and causes several toxic symptoms when dermal and respiratory exposu-re to DMF is prolonged.
It is supposed that DMF provoked toxic reaction in the liver during the metabolic process of the DMF-injected experimental animal. Therefore, the authors observed changes cytoplasmic organelles of the hepatic parenchymal cells in order to demonstrate the effect of DMF on the mouse liver.
Healthy male mice of ICR strain were used in this experiment and the weight of the experimental animals were around 20gm. The animals of the experimental group were administered DMF diluted in the water for injection, by intraperitoneal injec-tion in a dose of 1.5m1 per kg of body weight in a volume of 0.2m1. The animals of the control group were administered only water for injection.
The experimental animals were killed at intervals of 6, 12, 24 and 48 hours after administration of DMF, respectively. Liver specimens of 1mm3 size were prefixed in the 2% glutaraldehyde-2.5% paraformaldehyde phosphate buffer solution (pH 7.2) and post-fixed in the 1% osmic acid. After specimens were dehydrated, and embedd-ed in the epon 812, ultrathin sections (600-800 A ° thickness) were made and double stained with uranyl acetate and lead citrate: These preparations were observed with JEM ´100B electron microscope.
The results obtained were as follows:
1. Cisternae of rough endoplasmic reticulum were intensely dilatated and fragmented partly.
2. Smooth endoplasmic reticulum was markedly proliferated and glycogen par-ticles were markedly decreased or depleted.
3. The atrophies of the Golgi complex were found.
4. Primary lysosomes and secondary lysosomes-residual bodies, autophagic vacuole and multivesicular bodies were increased in number.
5. Numerous lipid droplets of irregular size were produced. Consequently, it is concluded that DMF would induce the degenerative changes in cytoplasmic organelles of the hepatic parenchymal cell in the mouse.
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