Inhibitors of elastase in airway lavage samples from ventilated preterm human neonates.

Surplus elastase released from neutrophils during lung injury is balanced mainly by alpha1-protease inhibitor (alpha1-PI) and by two acid-resistant inhibitors. The latter include mucus protease inhibitor (MPI, also named SLPI, BSI, ALP) and elastase-specific inhibitor (ESI or Elafin), but their functional role during the neonatal period has not yet been characterized precisely. The saline airway lavage samples from neonates intubated for respiratory distress were separated by centrifugation into a cellular and a soluble, supernatant fraction and then analyzed.

Cellular association of antiproteases in lavages from ventilated preterm human neonates.

Lung antiprotease activity is routinely assayed in the supernatant of bronchoalveolar lavage fluid (BALF). In this study the cellular fraction of lavages was also analyzed. Functionally active acid-resistant inhibitors with molecular masses characteristic of the mucus proteinase inhibitor (MPI, 14 kDa) and elastase-specific inhibitor (ESI, 7 kDa) were demonstrated by gel chromatography.

Isolation and characterization of trypsin-like and chymotrypsin-like proteinases from human cholesteatoma.

The mast-cell-specific proteolytic enzymes tryptase and chymase were identified in and isolated from cholesteatoma in a ratio similar to that found in human skin. We assume that this ratio reflects a similar distribution of tryptase-containing and tryptase/chymase-containing mast cells in both these tissues. It seems conceivable that mechanisms able to trigger excessive and/or continuous mast cell degranulation in the middle ear might be causative for the formation of cholesteatoma either directly or via primed chronic inflammatory reactions.

Amino acid sequences of mammalian kazal-type proteinase inhibitors from salivary glands.

1. The amino acid sequences of bikazins (the double-headed Kazal-type proteinase inhibitors from submandibular glands) isolated from the snow leopard (Unica unica), the European mink (Mustela lutreola), and the European pine marten (Martes martes) were determined. 2.

Interaction of human mast cell tryptase and chymase with low-molecular-mass serine proteinase inhibitors from the human respiratory tract.

Mast cell degranulation results in the release of serine class proteinases with trypsin- and chymotrypsin-like specificity. While looking for natural protein inhibitors of these enzymes, we studied their reactions with the double-headed Kunitz-type inhibitor, bikunin, and the human bronchial secretion inhibitor (BSI), which are the only known low-molecular-mass proteinase inhibitors of the human respiratory tract. Both trypsin and chymotrypsin can be inhibited by these inhibitors.