Ethyl carbamate(EC) has been identified at low microgram quantities in various fermented beverages, distilled products and tobacco smoke. EC has long been known as a carcinogen. Oxidation of the ethyl group of EC is followed by dehydration to
yield
the
carcinogen vinyl carbamate (VC). This is further oxidized to vinyl carbamate epoxide (VCO). VC and VCO proved to be much more carcinogenic than EC
The objective o this study is to compare the potency of carcinogenic ability in skin tumors induced by EC, VC, or VCO. The studies, such as electron microscopy, flow cytometry and immuno-histochemical stain were performed.
@ES The results are summarized as follows:
@EN 1. on electron microscopic examination. Dark cells were present in all of the groups except the control group. In keratoanthoma and squamous cell carcinoma, electron microscopic examination showed distinctive morphologic features which were
increased number of dark cells, intracytoplasmic or nuclear inclusions. Villous projection and widening of intercellular space. Many intracytoplasmic vacuoles were present more frequently in papilloma than other tumors or in the control group.
2. In the DA histogram, control group, papilloma and keratoacanthoma specimens showed diploid pattern but among three of the squamous cell carcinoma lesions only one showed an aneuploidy.
3. Among five of the squamous cell carcinoma specimens one disclosed a diffuse staining pattern of p53 protein by the immunoperoxidase method. The others such as the control group, papilloma or keratoacanthoma lesions stained negative for p53
protein.
4. From the above results it is concluded that VC and VCO have more potent carcinogenic potential than EC. Various skin tumors, such as papilloma, keratoacanthoma or squamous cell carcinoma were produced by above carcinogens. Even though these
tumors
showed various, distinctive electron microscopic changes, most of the lesions revaled a minor degree of quantitative abnormality in flow cytometry and p53 protein taining.
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