chymostatin and phosphoramidon

The intratracheal (i.t.) instillation of Sephadex beads into rat induced inflammation and a 30-fold increase in the endothelin-1-like immunoreactivity (ET-1-LI) of broncho-alveolar lavage fluid. The levels were highest 24 h after the instillation and had declined significantly after 48 h. At a dose of 1 mg kg-1 i.t., the glucocorticosteroid budesonide almost abolished this response. Phosphoramidon, which inhibits neutral endopeptidase, an enzyme reported to degrade ET-1 and also to inhibit the endothelin-converting enzyme, potentiated the Sephadex-induced rise in ET-1-LI. Chymostatin and heparin, which are reported to reduce the formation of ET-1, did not affect the increase in ET-1-LI. The present model represents a very reactive system for analyzing the changes in ET-1 levels during inflammation.

Topics: Animals; Bronchoalveolar Lavage Fluid; Budesonide; Chromatography, High Pressure Liquid; Dextrans; Endothelin-1; Enzyme Inhibitors; Glycopeptides; Heparin; Hydrogen Peroxide; Male; Oligopeptides; Pneumonia; Pregnenediones; Rats; Rats, Sprague-Dawley

High activities of the neutrophil proteases, elastase and cathepsin G, are found in the sputum of patients with cystic fibrosis (CF). Because both proteases have been shown to be potent secretagogues for airway submucosal glands, and because hypersecretion is a characteristic feature of CF, the objective of the present study was to examine whether there is secretagogue activity in CF sputum, and to determine the contribution of neutrophil proteases to the secretagogue activity. Confluent monolayers of cultured bovine tracheal serous cells were pulse-labelled with Na2(35)SO4, incubated with diluted CF sputum supernatants in the presence or absence of different protease inhibitors, and the subsequent release of the radio-labelled macromolecules was measured. CF sputum potently induced secretion concentration-dependently. Addition of the selective neutrophil elastase inhibitor ICI 200,355 inhibited the secretory response to CF sputum supernatant by 89%. Addition of a cathepsin G-inhibitor resulted in further inhibition of the secretory response. Addition of phosphoramidon, a drug known to inhibit Pseudomonas aeruginosa elastase, had no effect. We conclude that CF sputum potently stimulates airway submucosal gland cell secretion. These studies with protease inhibitors suggest that neutrophil proteases account substantially for the secretagogue activity present in CF sputum.

Topics: Adult; Animals; Cathepsin G; Cathepsins; Cattle; Cells, Cultured; Cystic Fibrosis; Exocrine Glands; Glycopeptides; Humans; Leukocyte Elastase; Oligopeptides; Pancreatic Elastase; Protease Inhibitors; Serine Endopeptidases; Sputum; Trachea

This study examined the effect of some proteinase inhibitors on liquefaction of human semen. It revealed that a strong plasmin inhibitor, 6-amidino-2-naphthyl-6-guanidinobenzoate dihydrochloride (Fusan) showed a significant inhibition of liquefaction, while t-amino caproic acid (t-ACA) showed a weak retardation effect. In terms of sperm quality after liquefaction, Fusan (10 mM), ethyl diamine tetra-acetic acid (EDTA) and Urinastatin completely inhibited sperm motility. Fusan (1 mM) and Lima bean trypsin inhibitor (LBTI) decreased sperm motility significantly, while leupeptin and t-ACA had little effect. Leupeptin, LBTI, t-ACA and Fusan (1 mM) did not affect sperm speed. 50% inhibition of sperm motility was calculated to be approximately 1.7 mM of Fusan concentration. In addition, two inhibitors, Chymostatin and Phosphoramidon were also tested with each experiment and had no effect on liquefaction or on sperm motility and speed. These results strongly suggest that plasmin may play an important role in the liquefaction process of human semen.

Topics: Adult; Benzamidines; Edetic Acid; Glycopeptides; Glycoproteins; Guanidines; Humans; Male; Oligopeptides; Plant Proteins; Protease Inhibitors; Semen; Sperm Motility

We examined conversion of Big endothelin-1 (ET-1) to mature ET-1 and pressor action during perfusion of the isolated perfused rat lung with Big ET-1. Big ET-1 caused a concentration-related increase in perfusion pressure and the pressor molar potency of the peptide was fivefold less than that of ET-1. Pressor responses to Big ET-1 were accompanied by an increase in immunoreactive-ET (IR-ET) levels in the perfusate and in the lung tissues. Pretreatment with phosphoramidon (10(-4) M), a metalloproteinase inhibitor, markedly suppressed the pressor action and increment in IR-ET in the tissues. Unexpectedly, the amount of IR-ET in the perfusate during perfusion of Big ET-1 was not influenced by phosphoramidon treatment. On the other hand, chymostatin, an inhibitor of chymotrypsin-like enzymes, effectively suppressed IR-ET levels in the perfusate; however, this enzyme inhibitor was without effect on the pressor action of Big ET-1 or on the increase in IR-ET levels in lung tissues. We tentatively conclude that the phosphoramidon-sensitive conversion of Big ET-T to ET-1 is linked to the pressor action of Big ET-1 in the isolated perfused rat lung. In addition, it seems likely that chymostatin-sensitive conversion of Big ET-1 to ET-1 does not play a major role in the conversion of the precursor to the mature form. We propose that IR-ET present in the tissues rather than that in the perfusate is a better indicator of the functional conversion of Big ET-1 in the rat lung.

Topics: Animals; Aspartic Acid Endopeptidases; Chymotrypsin; Dose-Response Relationship, Drug; Endothelin-1; Endothelin-Converting Enzymes; Endothelins; Glycopeptides; In Vitro Techniques; Kinetics; Lung; Male; Metalloendopeptidases; Oligopeptides; Perfusion; Protein Precursors; Pulmonary Circulation; Rats; Rats, Sprague-Dawley

Nonvolatile and thermolabile antibiotics are investigated both by field desorption and by secondary ion mass spectrometry (SIMS). It has been successfully demonstrated that these two methods are complementary in obtaining informations about molecular weight and structure. Although FD is most widely used for the investigation of nonvolatile biologically active compounds, there are some compounds of which FD can not provide reliable information. SIMS is successfully applied to obtain structural information of these compounds. SIMS spectra frequently depend on the surface conditions of sample holder materials.

Topics: Aminoglycosides; Anti-Bacterial Agents; Antipain; Dihydrostreptomycin Sulfate; Glycopeptides; Guanidines; Inositol; Mass Spectrometry; Molecular Weight; Nucleosides; Oligopeptides; Organophosphorus Compounds; Paromomycin