Search

Objective and Design: There is evidence that substance P (SP) is involved in events related to allergic and non-allergic rhinitis. Furthermore, some effects of SP seem to be greater in subjects suffering from allergic rhinitis than in non-allergic subjects. To investigate if these effects may be partly mediated by histamine release (HR) we studied the influence of SP on HR from nasal mucosa of subjects with and without allergic rhinitis using an in vitro organ culture system.¶Subjects: Nasal mucosa of the inferior turbinate was obtained from ten patients suffering from allergic rhinitis and eighteen non-allergic subjects receiving surgical therapy for nasal obstruction.¶Methods: Tissue samples of nasal mucosa were stimulated with 10-5 M SP or with 10-5 M Ca-ionophore A23187 for 120 minutes, and the histamine content was determined in the culture supernatant.¶Results: Both SP and Ca-ionophore A23187, caused a significantly higher HR from the samples of the non-allergic group (p

Previous studies have shown that nasal allergen provocation leads to dose-dependent increases of inflammatory mediators, e.g. histamine, kinins, LTC4 and PGD2 in nasal lavages. To investigate further the interaction of these mediators, a titration study with intranasal bradykinin (Bk) application (maximal dose 100 nmol/nostril) and consecutive lavage were performed in eight grass-pollen-allergic patients out of season, and five controls. The nasal lavages were analysed for albumin, N-alpha-tosyl-L-arginine methyl ester (TAME) esterase activity, histamine, 9 alpha,11 beta-PGF2, and LTC4. The clinical reactions were measured with a subjective symptom score. A dose-dependent elevation of albumin was found which was significantly higher in patients with allergic and non-allergic rhinitis compared with normal volunteers. TAME-esterase activity also increased in relation to the dosage of Bk given without significant difference between the various groups. No influence on histamine, LTC4 and 9 alpha,11 beta-PGF2, release (PGD2 metabolite) was seen. Short-lasting clinical symptoms like irritation, sneezing, and obstruction were noticed after the two highest Bk dosages (10 and 100 nmol). We conclude that intranasally applied Bk induces a dose-dependent plasma leakage into the nasal cavity, which is significantly higher in patients with seasonal allergic rhinitis out of season compared to normals. Bk does not seem to affect the mast cell since histamine, LTC4 and 9 alpha,11 beta-PGF2 levels do not alter. The ability to induce relevant symptoms of rhinitis provides strong support for the hypothesis that kinins may be important mediators of inflammatory disorders of the upper airways.

Kinins are potent inflammatory mediators, liberated from kininogens by different kininogenases. The aim of this study was to investigate the kinin generation pathways in acute and chronic inflammation of the lower airways. We studied bronchoalveolar lavage fluid (BALF) of patients with acute pneumonia, patients with chronic bronchitis and healthy controls. Kinins were determined by radioimmunoassay (RIA). Plasma kallikrein (pl-Kal), alpha2-macroglobulin (alpha2-M) and toluenesulphonylarginine methyl ester (TAME) esterase activity (TAME-ea) were studied in BALF before and after gel filtration chromatography. Plasma kallikrein and alpha2-M were measured using two newly developed sandwich enzyme-linked immunosorbent assays (ELISAs). TAME-ea was measured by a radiochemical assay. After gel filtration, inhibition of TAME-ea with benzamidine, soy-bean-trypsin inhibitor (SBTI) and aprotinin was performed. Kinins and TAME-ea did not differ significantly between acute pneumonia and chronic bronchitis, whereas pl-Kal and alpha2-M values were significantly higher in acute pneumonia. Gel filtration revealed the highest TAME-ea peak in acute pneumonia corresponding with the first alpha2-M peak at approximately 800 kDa, whereas in chronic bronchitis the highest peak was found at approximately 40 kDa. The inhibition test showed that the TAME-ea peak at approximately 800 kDa was due to pl-Kal and the TAME-ea peak at approximately 40 kDa was mainly due to tissue kallikrein. High peaks of alpha2-M and pl-Kal were found in pneumonia and only small peaks were seen in chronic bronchitis. We conclude that in acute airway inflammation kinins seem to be mainly generated by plasma kallikrein whereas in chronic inflammation, kininogenases other than plasma kallikrein, such as tissue kallikrein, seem to be more important.

Hageman factor (FXII, HF) is a monomeric plasma zymogen that is capable of autoactivation to the serine protease FXIIa in the presence of negatively charged surfaces such as glass, kaolin, ellagic acid and dextran sulfate. FXIIa activates prekallikrein to kallikrein which in turn digests high molecular weight kininogen (HK) to produce the vasoactive peptide bradykinin (BK). Known natural activators of FXII and the contact system include heparin, sulfatides, phospholipids, endotoxin, and urate crystals. We now present evidence that FXII can undergo activation in the presence of phosphate ions (P(i)) and certain divalent metal ions. FXII (1 microgram/ml) and prekallikrein (1 microgram/ml), in HEPES buffered saline, pH 7.4, were incubated with 0-100 mM sodium phosphate, 0-200 microM zinc chloride, and 0.6 mM Chromozym-PK; absorbance at 405 nm was monitored. Graphic analysis of the data indicated reciprocal activation of the two enzymes within 60 min which was dependent upon Zn(II) and P(i). While Ca(II) did not replace Zn(II) as an activator it significantly enhanced Zn(II)- and P(i)-dependent activation of FXII. Maximum activation occurred at 1-10 mM P(i) and approximately 25 microM Zn(II). Co(II), Cu(II) and Ca(II) were negative while Fe(II) was positive in the presence of 1 mM P(i). Cl-, SO4= and CO3=/HCO3- ions were negative when tested in the presence of 50 microM Zn(II). P(i) and Zn(II) ions promoted activation of FXII alone (but not prekallikrein) and the kinetics of this reaction suggested autoactivation. These data therefore suggest that physiological concentrations of P(i) and Zn(II) may be sufficient for a low-level turnover of the contact system in plasma which in turn may be responsible for the background levels of cleaved HK and BK found in normal plasma.

We evaluated the levels of bradykinin, albumin, TAME-esterase activity, histamine, PGD2 and LTC4 in bronchoalveolar lavage fluid from asthmatics and from patients with pneumonia, sarcoidosis, fibrosis, and chronic bronchitis. Compared with the results of healthy volunteers and atopic asymptomatic asthmatics the bradykinin levels and TAME-esterase activity were significantly elevated. In all other groups, histamine was additionally elevated in asymptomatic asthmatics, whereas albumin was elevated in symptomatic asthmatics and fibrosis patients, and decreased in chronic bronchitis and pneumonia patients. Following local intrabronchial allergen challenge of mild grass pollen asthmatics out of season bradykinin levels increased significantly, correlated with albumin, histamine and TAME-esterase activity. In contrast to the increased mediator concentrations in the early phase reaction there was no change of BAL cells in asthmatics compared to baseline and healthy volunteers. The presence of bradykinin in the bronchoalveolar space of patients with active pulmonary inflammations and bradykinin generation in asthmatics as a result of intrabronchial allergen challenge provides strong evidence that kinins are involved in inflammatory disorders of the lower airways.

Twenty-five patients with perennial rhinitis and a positive skin prick test (SPT) for Dermatophagoides pteronyssinus (Dp) and Dermatophagoides farinae (Df) were submitted to nasal provocation and the radioimmunosorbent test (RAST) for specific IgE-antibodies. We found a significant correlation in the reaction to both allergen extracts for all parameters examined. In addition, there was a significant correlation among the SPT, the RAST and the nasal provocation for Dp and between the SPT and the RAST for Df. In patients with perennial rhinitis we recommend the combination of all three methods to differentiate unspecific rhinitis from an allergic rhinitis. Only the patients with proved allergic rhinitis could benefit from a specific hyposensitisation.