The sialoglycoconjugates in the oviducts of fertile and postmenopausal women

Abstract

Objectives: The aim of the study was to investigate the distribution of the sialoderivatives of the glycoconjugates in the oviduct of normally menstruating and postmenopausal women. Methods: Biopsies of ampullary and isthmic portions of the oviduct were obtained from fertile women, in proliferative and secretive phases, and from postmenopausal subjects. The study was carried out using digoxigenin-labelled lectins (MAA, SNA and PNA) in addition to the use of enzymatic and chemical treatments to characterize the different glycosidic linkages of the sialoderivatives and to obtain information on their structure. Results: No appreciable difference in sialoderivatives distribution was observed among the oviducts, particularly at the epithelium luminal surface, of the fertile women in the two menstrual cycle phases or among those of the fertile and some postmenopausal women, independently from age. Moreover, no appreciable difference of distribution was observed between the ampullary and the isthmic portions in both the study groups. Conclusions: In the fertile women sialoderivatives present at the luminal surface of the epithelial cells could play a role in sperm capacitation and mobility, and facilitate the transit of the egg and of the early embryo along the oviducts. The similar distribution of sialoderivatives in the oviduct epithelium of some postmenopausal women of different age, compared to the fertile ones, suggests a maintaining of some functions of the organ, independently from the age of the woman. This could be due, in some cases, to the influence of remaining still sufficient sex hormonal levels.

Morphological and glycan features of the camel oviduct epithelium

“…The lectins permit the characterization of the glycoconjugates (Spicer and Schulte, 1992). Thus, lectin histochemistry has been successfully used to demonstrate the in situ distribution of glycoconjugates in several mammalian oviducts such as mice (Lee et al, 1983), humans (Schulte et al, 1985;Kiss et al, 1998;Gheri et al, 2007), hares (Menghi et al, 1988), rats (Menghi et al, 1989), pigs (Raychoudhury et al, 1993;Walter and Bavdek, 1997), rabbits (Menghi et al, 1995), hamsters (El-Mestrah and Kan, 1999), monkeys (Jones et al, 2001) and horses (Ball et al, 1997;Desantis et al, 2004Desantis et al, , 2005. Among the carbohydrates that constitute the oligosaccharide chains in glycoproteins, sialic acids are known to be a large family of nine-carbon carboxylated sugars that usually occupy the terminal position of the oligosaccharides and, due to their net negative charge, act as ligands in recognition phenomena (Schauer, 1985;Varki, 1997) as well as in vitro sperm capacitation (Banerjee and Chowdhury, 1994;Focarelli et al, 1995) and sperm-egg interaction (Geng et al, 1997;Cortés et al, 2004).…”

Sialylation: fate decision of mammalian sperm development, fertilization, and male fertility

“…The epithelial cells lining the lumen of the fallopian tube are covered with abundant sialylated derivatives, which facilitate the molecular recognition and movement of sperm within the female reproductive tract [170]. The sialylated lactosamine on the ampullary epithelial cells of the fallopian tube can bind to the sialic acid on the head of the sperm.…”

Sequential Injection-Immunoassay System with a Plain Glass Capillary Reactor for the Assay of Hyaluronan

“…Immunoassay and bioassay, including those that utilize specific biomolecular recognitions other than antigen-antibody pairs, [1][2][3] have been widely used for chemical/biochemical analysis. These techniques normally involve multi-step operational procedures that require precise timing and small reagent volume manipulation, which are highly time consuming and subjected to human errors when manually operated.…”