Inhibition of elastolysis by proteinase inhibitors from chick plasma and aorta.

Chick plasma contains inhibitor(s) against trypsin and elastase which also appear to retard the degradation of tropoelastin by arterial tissue extracts. Chick aorta extracts also contain similar inhibitors against elastase and trypsin. Both levels of the plasma inhibitor(s) and inhibitor(s) extracted from thoracic aorta increase during early stages of growth and maturation. There is a three- to four-fold increase in the levels of the inhibitor(s) in chick plasma and aorta between one to four weeks after hatching. Of particular interest are the observations that the presence of the inhibitor(s) retards the conversion of soluble elastin (tropoelastin) to smaller elastin peptides. Subsequently, it is speculated that in addition to other vital roles, such proteinase inhibitors may also act in regulating elastogenesis and elastin fiber formation.