Abstract
Abstract: :
Purpose: The purpose of this study is to analyze elements and their localization of the secretory granules in the palpebral conjunctiva of aged normal Wistar Kyoto rats by energy dispersive x–ray analyzer (EDX), and to compare them with young normal Wistar Kyoto rats. Materials and methods: We used 3–month–old and 15–month–old Wistar Kyoto rats. Immediately after the palpebral conjunctivae were excised, they were frozen with slushy nitrogen and then put into liquid nitrogen. Ultra–thin sections were made with a cryo–ultramicrotome, freeze–evaporation–dryed, carbon–coated and observed under a transmission electron microscope (TEM). Elements of the secretory granules in the palpebral conjunctiva of 15–month–old rats were analyzed with EDX and compared them with 3–month–old rats. Results: We detected Na, Mg, P, S, Cl and K in the secretory granules and in the surrounding area of secretory granules of 3–month–old rats with EDX. On the other hand, we detected Na, P, S, Cl and K in the secretory granules, and Na, Mg, P, S,K and Ca in the surrounding area next to secretory granules of 15–month–old rats. Remarkably, Ca was detected in the surrounding area next to secretory granules of 15–month–old rats. Discussion: By the methods we used in this study, morphology and elements of conjunctiva were preserved well. We showed that almost all elements preserved through aging, but Ca deposited in the high electron density area next to secretory granules. Conclusions: The physical fixation, ultra–thin freeze– sectioning method and freeze– evaporation–drying method are useful for the detection of elements in ocular tissues.
Keywords: aging • conjunctiva • calcium