IMMUNOHISTOCHEMICAL IDENTIFICATION OF THE UNCOUPLING PROTEIN IN HUMANHIBERNOMA

The expression of the uncoupling protein (UCP), a protein unique to br own adipocyte mitochondria, was studied in sections of a human hiberno ma by means of immunohistochemistry. Multilocular, but not unilocular, adipocytes expressed the UCP in the tissue. Further, the immunostaini ng was not uniform in multilocular cells, because small adipocytes wit h finely multivacuolar or scanty lipid deposit showed more intense sta ining. This pattern is similar to that found in brown adipose tissue. Ultrastructural investigation confirmed that a majority of proliferati ng cells had the morphological characteristics of brown adipocyte. Res ults indicate that adipocytes in hibernoma may be very close to brown adipocytes both morphologically and immunocytochemically.