Comparative studies on the localization of esteroproteases and kallikrein-like activity in primate organs

Various organs of three species of monkey were screened histochemically for esteroproteases using N-acethyl-L-methionine-alpha-naphthylester (alpha N-O-met) as the substrate and also for enzymes with kallikrein-like activity using D-Val-Leu-Arg-4-methoxy-2-naphthylamide as the substrate. Characteristic differences were found in the localization of the reaction products obtained with both substrates. In the main salivary glands, esteroproteases (alpha N-O-met reactivity) were found in mucous cells (submandibular gland), intercalated duct cells (parotid gland), acinar cells (sublingual gland), striated and interlobular duct cells (all glands). They were also localized in superficial lining epithelial cells of the digestive system, in liver cells, and acinar cells of the pancreas. Enzymes with kallikrein-like activity were found only in the striated and interlobular duct cells of salivary glands, in acinar cells of the pancreas, and in proximal tubular cells of the kidney. Free cells (including mast cells) normally distributed in the connective tissue of various organs showed reactivity towards alpha N-O-met. Some of these cells were also reactive against Val-Leu-Arg-4-MNA.