title: The endometrium of the anoestrous female pig: studies on infiltration by cells of the immune system.
abstract: The aim of this study was to investigate the distribution of immune cells in the endometrium of anoestrous female pigs, five sows in anoestrus by lactation and five pre-pubertal gilts (Swedish Landrace x Swedish Yorkshire). Uterine samples, taken immediately after slaughter, were fixed, embedded in plastic resin and stained with toluidine blue or cryo fixed and stored in a freezer at -70 degrees C until analysed by immunohistochemistry with an avidin-biotin peroxidase method. Immune cells in the surface (luminal) and the glandular epithelium as well as the subepithelial and the glandular connective tissue layers were counted using light microscopy. In the surface (luminal) and the glandular epithelia of gilts and sows, lymphocytes were the predominant immune cells found. There were no significant differences between gilts and sows. Macrophages were detected in the glandular epithelium of sows but not in gilts. In the subepithelial and the glandular connective tissue layers of both gilts and sows, lymphocytes were also the most common immune cells found. The numbers of lymphocytes and macrophages were significantly higher in the sows than in the gilts (p <or= 0.05) in both the layers of connective tissue. Numbers of plasma cells, mast cells, eosinophils and neutrophils in the connective tissue were low and not significantly different between sows and gilts. In both the surface (luminal) epithelium and the subepithelial connective tissue, higher numbers of CD2 than CD3 positive cells were found (p <or= 0.01). The numbers of CD2 positive cells in both epithelium and connective tissue and the number of CD3 positive cells in the epithelium were significantly higher in the sows than the gilts (p <or= 0.05). A few CD79 positive cells were found in the subepithelial connective tissue and none in the epithelia. A few CD14 and SWC3 positive cells were found in the epithelia. The numbers of CD14, SWC3 and MHC class II positive cells were significantly higher in the sows than in the gilts (p <or= 0.05) in the subepithelial connective tissue. In conclusion, the distribution of immune cells in the endometrium of anoestrous female pigs was affected by experienced pregnancy and parturition. In sows with lactation-induced anoestrus, there was a markedly higher cell infiltration (lymphocytes and macrophages) than in the pre-pubertal gilts. In pre-pubertal gilts, lymphocytes dominated, which indicates a role in the maturation of the endometrium.
authors.affiliation: Division of Comparative Reproduction, Obstetrics and Udder Health, Department of Clinical Science, Swedish University of Agricultural Sciences (SLU), Uppsala, Sweden. jatesada.jiwakanon@kv.slu.se
authors.forename: J
authors.initials: J
authors.lastname: Jiwakanon
authors.forename: E
authors.initials: E
authors.lastname: Persson
authors.forename: A-M
authors.initials: AM
authors.lastname: Dalin
mesh_terms: D000375:Aging / Q000276:immunology / Q000502:physiology; D000780:Anestrus / Q000276:immunology / Q000502:physiology*; D000818:Animals; D004717:Endometrium / Q000166:cytology* / Q000276:immunology* / Q000473:pathology; D005260:Female; D007150:Immunohistochemistry / Q000662:veterinary; D007774:Lactation / Q000276:immunology / Q000502:physiology; D016131:Lymphocyte Subsets / Q000276:immunology; D008214:Lymphocytes / Q000276:immunology; D008264:Macrophages / Q000276:immunology; D012741:Sexual Maturation / Q000276:immunology / Q000502:physiology; D013552:Swine