Endocrine Abstracts

Introduction. Lipocortin-1 (annexin-1 and p35) is a 37-kDa Ca²⁺-dependant membrane-binding protein that has
anti-inflammatory, anti-mitotic and anti-proliferative properties.With these properties in mind it was hypothesised that lipocortin-1 may have an important role in the endometrium. Therefore, the aim of
this study was to determine the distribution of lipocortin-1 in normal and abnormal endometrial tissue.
Methods. Formalin fixed paraffin embedded sections were immunostained. Sections underwent dewaxing and rehydration, endogenous peroxidase blocking, and after microwave antigen retrieval blocking of non-specific protein binding. Sections were incubated in primary antibody (lipocortin-1 specific polyclonal antibody raised in sheep), diluted at 1:10000 for one hour at room temperature. A biotinylated secondary antibody followed by streptavadin/peroxidase complex was applied. Staining was then visualised with diaminobenzidine. Mast cell staining was used as positive control for lipocortin-1. Results. The number of slides with positive lipocrotin-1 staining in relation to cell type. Menstrual endometrium (n=6); epithelium 6/6, stroma 4/6, endothelium 4/6. Secretory endometrium (n=9); epithelium 9/9, stroma 7/9, endothelium 8/9. Proliferative endometrium (n=10); epithelium 10/10, stroma 9/10, endothelium 9/10. Simple hyperplasia endometrium (n=9); epithelium 9/9, stroma 7/9, endothelium 9/9.Complex hyperplasia endometrium (n=4); epithelium 4/4, stroma 2/4, endothelium 4/4. Complex hyperplasia with atypia endometrium (n=8); epithelium 7/8, stroma 2/8, endothelium 8/8. Adenocarcinoma endometrium(n=13); epithelium 13/13, stroma 3/13, endothelium 11/13. Conclusion. Lipocortin-1 expression was present throughout the normal menstrual cycle and present in the epithelium and endothelium of the abnormal endometrium. However, lipocortin -1 was reduced markedly in the stroma of the abnormal endometrium. These data suggest that lipocortin -1 may have a role to play in endometrial function.