مطالعه هيستوشيميايي آنژيوژنز سيستم پورت هيپوتالاموسي - هيپوفيزي در جنين هاي رت

Histochemical study of hypothalamo - hypophyseal portal system angiogenesis in rat embryos

Introduction: Angiogenesis is controlled by series of cellular interactions which are mediated by cell surface glycoconjugates terminal sugars. The aim of this study was to investigate the distribution and changes of the cell surface terminal sugars during hypothalamo- pituitary portal (HPP) system angiogenesisʹ in rat embryos. Methods: In this study, 70 N-many rat. fetuses (10-20 gestational days) were used by lectin histochemichal technique as a tool to study distribution of the glvcoconjugates and their changes during HPP system angiogenesis. All paraffin sections were incubated with different HRP- lectins from Vicica villosa (VVA), Glycine max (SBA) and Wistaria floribunda (WFA) specific for terminal sugars D-Gal, a, fi-D-GaINAc and D- GalNAc of complex glycoconjugates, respectively. On the basis of staining intensity, the sections were graded and nonparametric statistical test was used to compare differences between samples. Results: The results demonstrated that some cells around Rathkeʹs pouch reacted with VVA .from day 13 and increased to day 14 and then decreased afterward, significantly (P<0.05). Some cells around Rathkeʹs pouch reacted with SBA from day 14 to day 18 and then decreased afterward (P<0.05). Many cells around Rathkeʹs pouch reacted with WFA from day 13 and increased on days day 14 and day 15 (P<0.05), then decreased with developmental advancement. Conclusion: Our findings indicated that the distribution and changes of glycoconjugates with terminal sugars D-Gal, a, Beta-D-Ga1NAc and D- GaINAc were regulated spatiotemporally and might play critical role (s,) in cell interactions and tissue differentiations such as angiogenesis during embryonic development.