Histochemical changes of the glycosaminoglycans in the uterine cervix of pregnant rats after local injection of hyaluronidase

PURPOSE: to study the histochemical changes related to the uterine cervix glycosaminoglycan of the albino female rat, after local ministration of hyaluronidases at the end of pregnancy. METHODS: ten female rats with positive pregnancy tests were randomly distributed in two numerically equal groups. The control group (Cg) was built up with rats that received a single dose of 1 mL of distilled water in the uterine cervix, under anesthesia, at the 18th pregnancy day. In the experimental group (Exg), the rats received 0.02 mL of hyaluronidase, diluted in 0.98 mL of distilled water (1 mL as a total), under the same conditions as the Cg. At the 20th pregnancy day, the rats were anesthetized once again and submitted to dissection, and the cervix prepared for histochemical study with alcian blue dye and its blockades (pH=0.5, pH=2.5, methylation and saponification). RESULTS: strongly positive reaction in the lamina propria (+3) has been seen in the Cg, and negative reaction in the Exg, with pH= 0.5 alcian blue staining. With pH= 2.5, staining has also been strongly positive (+4) in the Cg, and weakly positive (+1) in the Exg slide. After methylation, both groups have shown negative reaction, with pH= 2.5 alcian blue staining. The lamina propria staining became negative after methylation in both groups, followed by saponification and enzymatic digestion on slide. CONCLUSIONS: there is clear predominance of sulphated glycosaminoglycans in the Cg as compared to the Exg and a small amount of identified carboxylated glycosaminoglycans in the Exg. The changes evidenced in the extracellular matrix have suggested that the hyaluronidase injected in the uterine cervix has promoted biochemical changes compatible with cervix maturation.