QUANTITATIVE IMMUNOHISTOCHEMICAL EVALUATION BY IMAGE-ANALYSIS OF METALLOTHIONEIN IN COPPER-LOADED RAT-KIDNEY

Kidneys of copper-loaded rats were investigated immunohistochemically with a directly peroxidase-conjugated monoclonal antibody against meta llothionein (MT). By means of an image analyzing system the area and t he staining intensity of MT immunoreactivity in the proximal convolute d tubule (PCT) cells were determined. In the present study we compared the data obtained by image analysis with analytically determined tiss ue copper and MT concentrations of rats fed a high-copper diet (1 g/kg ) for 16 weeks and sacrificed sequentially during this period. Our res ults provide evidence that the area of MT immunoreactivity correlates significantly with tissue copper and MT concentrations. Both the coppe r and MT concentrations in kidney rose to a maximum at 8 weeks and rem ained constant thereafter. The observed rise in the staining intensity of MT in PCT cells to a maximum at 6 weeks, which subsequently declin ed, suggests a continuing redistribution of copper and MT in the kidne ys even after a maximum of concentration copper and MT is reached in t he tissue.