Demonstration of cathepsins H and L in rat tissues.

Using immunohistochemical techniques, cathepsins H and L were shown to be widely distributed in rat tissues. The intracellular location of the enzymes in the parenchymatous tissues was granular under light microscopy and was shown to be lysosomal by immunoelectron microscopy of the kidney proximal tubule epithelium. In the lymphatic tissue both cathepsins H and L were seen in the reticular cells and not in the lymphoid cells. The locations of the two enzymes differed from each other in some tissues suggesting that the enzymes may have specialized functions in those tissues.