Histomorphometry and detection of glycosaminoglycans in the endocervical epithelium of pregnant rats after local administration of hyaluronidase

Abstract

Objective: The aim of the study was to detect the presence of glycosaminoglycans and to investigate histomorphometric aspects of the endocervical epithelium in pregnant rats after local administration of hyaluronidase. Materials and methods: Ten pregnant rats were randomly distributed into two groups. On day 18 of pregnancy, 1mL of distilled water and 0.02 mL of hyaluronidase were administered to the control group (CG) and the study group (SG), respectively. On day 20 the rats were sacrificed, followed by dissection and removal of the uterine cervix, which was prepared for histomorphometry (endocervical epithelium thickness and leucocyte infiltration) and for immunohistochemistry with alcian blue reaction and its respective blockers. The paired Student t test was used to compare the groups. Results: The SG was characterized by reduced epithelial thickness (mean: 291.01±71.1 vs. 764.30±50.94; p<0.0001) and a larger number of eosinophils (mean: 3.72±1.60 vs. 0.54±0.70; p<0.0001). Alcian blue staining (pH 0.5) indicated a very strong reaction (3+) for the CG. With pH 2.5, the staining was also very intense (4+) in the CG. With methylation, both groups showed negative reactions after alcian blue staining (pH 2.5). With the methylation reaction followed by saponification and with enzymatic digestion of the lamina, staining showed a weak reaction (1+) in both groups. Conclusion: The SG presented with significant alterations related to the reduction of epithelial thickness and an increase in leucocyte infiltration. Furthermore, the use of hyaluronidase resulted in a significant decrease of the sulfated glycosaminoglycans.