Ultrastructural and ultracytochemical features of secretory granules in the ampullary epithelium of the hamster oviduct

Abstract

The epithelium of mammalian oviducts consists mainly of ciliated and non-ciliated secretory cells. In some mammals, secretory products originating from oviductal secretory cells have been shown to bind to the surface of, or accumulate within, ovulated eggs and/or developing embryos. These findings suggest that the secretions of the oviductal epithelial cells may play an important role in reproductive and developmental events that occur in the oviduct. In the present study, ultrastructural and cytochemical features of secretory cells in the hamster ampullary epithelium were shown by routine electron microscopy, lectin-gold cytochemistry and both conventional freeze-fracture and rapid-freezing techniques with special reference to the organizational aspects of their secretory granules. The use of ferrocyanide-reduced osmium tetroxide as a post-fixative in the Epon embedment of ampullary tissue samples also proved to be advantageous especially in revealing the carbohydrate contents of certain cellular compartments. The most conspicuous characteristic of the secretory cells, based on their staining property, was the presence of two types of secretory granules: those with a homogeneous electron-dense matrix and those with an electron-lucent matrix. Under favorable conditions, distinct features of the organizational arrangement of a crystalline lattice inside the secretory granules were also revealed. This well organized crystalline lattice shown in sections of Epon-embedded oviductal tissue was confirmed by examination of replicas of freeze-fractured oviducts prepared by the rapid-freezing technique. We also demonstrated with high resolution lectin-gold cytochemistry the intracellular distribution of lectin-binding glycoconjugates in the secretory cells of the hamster oviductal ampulla often in a linear array following the crystalline lattice. The results obtained in this study, taken together, provide insight into a possible link of the internal topographical features of oviductal secretory granules along with the cytochemical properties of their contents to the anticipated regulatory mechanism underlying their process of secretions.

Topographic and ultrastructural variations in isthmus segment of oviduct during oestrous cycle in Caprines

“…, ). The secretory granules observed in goat oviduct are similar in their fine morphology to those observed in rabbit and primates (Jansen and Bajpai ; Wheeler ; El‐Mestrah and Kan ). Presence of two types of secretory granules, i.e.…”

“…Estrogen induces hypertrophy, active ciliation, and formation of secretory granules (Verhage and Brenner 1975;Abe and Oikawa 1993;Vigil et al 2009Vigil et al , 2012. The secretory granules observed in goat oviduct are similar in their fine morphology to those observed in rabbit and primates (Jansen and Bajpai 1982;Wheeler 1982;El-Mestrah and Kan 1999). Presence of two types of secretory granules, i.e.…”

Cysteinyl leukotriene 2 receptor‐mediated vascular permeability via transendothelial vesicle transport

“…The cremaster muscle was excised and fixed immediately by immersion in 2.5% glutaraldehyde in 0.1 M cacodylate buffer, pH 7.4. After 2 h at 4°C, the tissue samples were washed 3 times with PBS and then trimmed into small pieces for Epon embedding (Epon 812), as described previously (19). One‐micrometer‐thick sections were first examined by light microscopy in order to locate the area of interest, after which Epon thin sections were cut with a diamond knife on a LKB ultrami‐crotome and mounted on copper grids.…”

Changes in the oviducal epithelium during the estrous cycle in the marsupial Monodelphis domestica

“…These differences may partly show in a varying morphology of the secretory granules depending on the oviducal area as shown in macaca (Odor et al. 1983) or the golden hamster (El‐Mestrah & Kan, 1999) where two types of secretory granules, some with internal lamellae‐like structures, were found. The secretory granules in the Monodelphis oviduct did not exhibit morphological differences between ampulla and isthmus.…”