Changes in mast cell phenotype in rat lung following infection with Nippostrongylus brasiliensis

Abstract

IntroductionPrevious studies by ourselves and others have shown that mast cells may undergo functional changes in the course of allergic and inflammatory disease [1]. Infection of the rat with the nematode parasite Nippostrongylus brasiliensis leads to an acute inflammatory response in the lung and intestine of the animal [2, 3]. We have now used this as a model system and have compared the properties of mast cells recovered from the peritoneum and by enzymatic dissociation of the lung, mesentery and prostate of normal and sensitised animals. Materials and methodsMale Sprague Dawley rats (ca 250 g) were used throughout. Lung, prostate and mesentery were dispersed into their component cells by treatment with the enzyme collagenase [4]. Peritoneal mast cells were obtained by direct lavage [4]. Where appropriate, animals were sensitised to N. brasiliensis and used two weeks later when the inflammatory response in the lung was maximal [5]. Histamine release was determined spectrofluorometrically as previously described [5]. Cytocentrifuge preparations of mast cells were fixed in either Carnoy's solution or formol saline and dried. The sides were then stained with alcian blue dye (30 min) and counterstained with safranin O (5 min) [6].The following secretagogues were purchased from Sigma unless otherwise noted: anti-rat IgE (ICN), compound 48/80, concanavalin A, dextran (RMM 70,000), histone, ionomycin (Calbiochem), ionophore A23187 and polymyxin B.