Immunohistochemical detection of LRP protein in the normal human lung.
In this study, we have determined the LRP (lung resistance-related protein) by immunohistochemical method. LRP belongs to proteins which cause the multidrug resistance (MDR). It has been found in various normal human tissues, where it plays a protective role against toxic compounds. Multidrug-resistant cells distribute the cytotoxic drug into the perinuclear region and then redistribute it back into the cytoplasm. It is just a hypothesis today that LRP can mediate drug resistance by regulating both the cytoplasmic redistribution and the nucleocytoplasmic transport of drugs. In order to detect LRP we have used the paraffin-embedded sections of the normal human lung tissue. LRP was predominantly located in two regions: 1) in bronchial epithelial cells and 2) in alveolar macrophages. Positive cells were coloured brown and showed strong reactivity. Negative control included the omitting of primary antibody and replacing it by buffer solution. Bronchial epithelial cells and alveolar macrophages stayed uncoloured, i.e. unreactive. (Fig. 5, Ref. 17.).