OBJECTIVE: Identification and quantitation of sulphated glycosaminoglycans (GAGs) in the uterus of female mice during the estrous cycle. METHODS: Four groups (n = 10 each) of virgin, 100-day old female mice were assembled according to the estrous cycle phase: proestrus, estrus, metaestrus and diestrus. Samples of the median portion of uterine horns were processed for light microscopy examination (H/E and Alcian blue + PAS). The GAGs were extracted and characterized by agarose gel electrophoresis. Data were analyzed by the unpaired Student's t-test. RESULTS: At light microscopy GAGs appear in all layers of the uterus, especially in the endometrium, between collagen fibers, in the basal membrane and around fibroblasts. Biochemical analyses disclosed presence of dermatan sulphate (DS), chondroitin sulphate (CS and heparan sulphate (HS) during all estral cycle phases. There was no clear electrophoretic separation between DS and CS, thus these two GAGs were considered together (DS+CS) (proestrus = 0.854 ± 0.192; estrus = 1.073 ± 0.254; metaestrus = 1.003 ± 0.255; diestrus = 0.632 ± 0.443 µg/mg). HS was as follows: proestrus = 0.092 ± 0.097; estrus = 0.180 ± 0.141; metaestrus = 0.091 ± 0.046; diestrus = 0.233 ± 0.147 µg/mg. The uterine content of DS+CS peaked at estrus (estrogenic action) and that of HS at diestrus (progestagen action). CONCLUSION: Due to a constant turnover process, there are definite alterations in the uterine profile of GAGs content during the estrous cycle in mice, which may be modulated by female sex hormones.
Sulphated glycosaminoglycans; Uterus; Estrous cycle; Mice
