title: Comparative ultrastructural analyses of platelets and fibrin networks using the murine model of asthma.
abstract: The murine Balb/c asthma model has been used successfully for a number of in vivo immunological applications and for testing novel therapeutics, and it is a reliable, clinically relevant facsimile of the human disease. Here we investigate whether this model can be used to study other components of the human body, e.g. ultrastructure. In particular, we investigate the effect of the phytomedicine Euphorbia hirta (used to treat asthma), on the ultrastructure of fibrin as well as platelets, cellular structures that both play an important role in the coagulation process. Hydrocortisone is used as positive control. Ultrastructure of the fibrin networks and platelets of control mice were compared to mice that were asthmatic, treated with two concentrations of hydrocortisone and one concentration of the plant material. Results indicate control mice possess major, thick fibers and minor thin fibers as well as tight round platelet aggregates with typical pseudopodia formation. Minor fibers of asthmatic mice have a netlike appearance covering the major fibers, while the platelets seem to form loosely connected, granular aggregates. Both concentrations of hydrocortisone make the fibrin more fragile and that platelet morphology changes form a tight platelet aggregate to a more granular aggregate not closely fused to each other. We conclude that E. hirta does not impact on the fragility of the fibrin and that it prevents the minor fibers to form the dense netlike layer over the major fibers, as is seen in untreated asthmatic mice. This ultrastructural morphology might give us better insight into asthma and the possible new treatment regimes.
authors.affiliation: Department of Anatomy, School of Health Sciences, Faculty of Health Sciences, University of Pretoria, BMW Building, P.O. Box 2034, Pretoria 0001, South Africa. resia.pretorius@up.ac.za
authors.forename: E
authors.initials: E
authors.lastname: Pretorius
authors.forename: O E
authors.initials: OE
authors.lastname: Ekpo
authors.forename: E
authors.initials: E
authors.lastname: Smit
mesh_terms: D000485:Allergens / Q000276:immunology; D000818:Animals; D018927:Anti-Asthmatic Agents / Q000627:therapeutic use*; D000893:Anti-Inflammatory Agents; D001249:Asthma / Q000097:blood* / Q000188:drug therapy; D001792:Blood Platelets / Q000187:drug effects / Q000648:ultrastructure*; D004195:Disease Models, Animal; D004305:Dose-Response Relationship, Drug; D028481:Euphorbia / Q000737:chemistry; D005337:Fibrin / Q000187:drug effects / Q000648:ultrastructure*; D006854:Hydrocortisone / Q000627:therapeutic use; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D008855:Microscopy, Electron, Scanning; D010047:Ovalbumin / Q000276:immunology; D008517:Phytotherapy; D010936:Plant Extracts / Q000627:therapeutic use
chemical_list: D000485:Allergens; D018927:Anti-Asthmatic Agents; D000893:Anti-Inflammatory Agents; D010936:Plant Extracts; D005337:Fibrin; D010047:Ovalbumin; D006854:Hydrocortisone