1. We examined the secretion of arginine amidase activity from rabbit aorta and ear arteries. 2. The amount of arginine amidase activity spontaneously secretion from the aorta was significantly less than that secreted from the ear artery. Dermatan sulphate significantly facilitated the secretion of arginine amidase activity from both the aorta and ear artery. 3. The dermatan sulphate-enhanced secretion of arginine amidase activity from the aorta and ear artery was reduced by denudation of the endothelium. 4. These findings may indicate that spontaneous release of arginine amidase activity from vascular smooth muscle and the enhancement of secretion of arginine amidase activity produced by dermatan sulphate depends on the endothelium.

We have previously reported that trypsin (EC 3.4.21.4)-like enzymes, showing lysine and arginine p-nitroanilidederivative hydrolyzing activities (arginine amidase activity, AA activity), which can be separated using aprotinin and lima bean inhibitor affinity columns, are secreted from rabbit arteries.1,2) Moreover, we showed that AA released from isolated rabbit ear arteries was accelerated by the addition of mucopolysaccharide sulfate derivatives; heparin, chondroitin sulfate, dextran sulfate and dermatan sulfate.