Lectin binding patterns of porcine oviduct mucosa and endometrium during the oestrous cycle

Abstract

Important functions of the oviduct during reproduction include the provision of an optimal environment for gametes and zygotes and nutrition of the early embryo. These functions are ensured by the secretion of an oviductal fluid which is known to contain organ-specific glycoproteins. Glycoconjugates of the apical glycocalyx are considered to play a major role in cell recognition and interaction processes. In the present investigation, binding patterns of Con A, HPA, LTA, RCA I, UEA I, and WGA were studied in defined segments of the oviduct (infundibulum, ampulla, isthmus) and in the uterus during the oestrous cycle. The carbohydrate distribution showed regional as well as time dependent differences. LTA, HPA and WGA reacted strongly with Golgi regions and secretory granules in the oviduct epithelium during the follicular phase, indicating high secretory activity. LTA, HPA, and UEA I also revealed a varying carbohydrate composition of the glycocalyx during the oestrous cycle. Prominent regional differences in glycoconjugate expression were shown in oviductal segments by LTA and HPA binding : during the follicular phase, LTA binding sites were only present on epithelial cells of the isthmic segment, the ampulla and infundibulum being unreactive. D-N-acetyl-galactosamine residues were demonstrated on ciliated epithelial cells of the ampulla and infundibulum exclusively during oestrus. The glycocalyx of uterine epithelial cells was clearly defined by HPA, WGA, LTA, RCA I and UEA I ; LTA binding was restricted to the secretory phase. The observation of regional and time dependent variability in glycoconjugate distribution strongly indicates their specific physiological functions in reproductive processes.Key words : Pig ; uterus ; oviduct ; glycoconjugates ; lectins. The female reproductive tract is the site of complex processes, such as oocyte maturation, capacitation of spermatozoa, fertilisation, and embryonic development. It has been considered that the oviduct and uterus-in addition to hormonal control-are influenced by oocyte or embryonic signals (Hunter, 1988). However, more detailed information on interactions between oviduct\uterine mucosa and the ovum or the early embryo is still lacking. Physiological significance was suggested for the luminal glycoconjugate-surface coat (glycocalyx) of the epithelial layer in the oviduct and uterus, and for the oviduct fluid. The apical glycocalyx acts as a mediator

Determination of glycosidase activity in porcine oviductal fluid at the different phases of the estrous cycle

“…On the one hand, it has been shown that Triticum vulgaris, specific against D-N-acetyl-glucosamine sugar residues, reacts strongly with the oviduct epithelium during the follicular phase (Walter & Bavdek 1997). On the other hand, studies with Helix pomatia (Walter & Bavdek 1997) and Dolichos biflorus lectins, which recognize a-GalNAc residues, have shown that the porcine oviduct expresses this sugar especially during the follicular phase. Therefore, oviductal hexosaminidase might have a role in remodeling the oviduct surface, thus affecting gamete interactions with oviductal cells.…”

“…In pigs, experiments with lectins show that carbohydrates are differently expressed among regions of the oviduct during the different phases of the estrous cycle (Raychoudhury et al 1993, Walter & Bavdek 1997, Sant'ana et al 2005. Lotus tetragonolobus lectin mainly recognizes a-L-fucose residues, and during the follicular phase its binding sites are only present on epithelial cells of the isthmic segment, the ampulla and infundibulum being unreactive (Walter & Bavdek 1997).…”

Oviduct binding ability of porcine spermatozoa develops in the epididymis and can be advanced by incubation with caudal fluid

“…Moreover, spermatozoa from the horse and human have also been reported to bind in greater numbers to the isthmus than to the ampulla [56,57]. It is important to realise that regional differences in the expression of glycoconjugates are apparent between segments of the porcine oviduct, and across the different stages of the oestrous cycle, thereby affecting the available binding sites [58]. It seems logical that the difference observed with binding is consistent with the normal physiological functions of the oviduct in these two regions: i.e.…”

Distribution of sialoglycoconjugates in the oviductal isthmus of the horse during anoestrus, oestrus and pregnancy: a lectin histochemistry study

“…In spite of their putative importance, sialoglycoconjugates have not been studied in horse. Lectins have been successfully used to demonstrate the presence of glycoconjugates in a number of studies including the in situ distribution of glycoconjugates in the mammalian isthmic oviduct, namely in mice (Lee et al, 1983), humans Wu et al, 1993;Kiss et al, 1998), hares (Menghi et al, 1988), rats (Menghi et al, 1989), pigs (Raychoudhury et al, 1993;Walter and Bavdek, 1997), rabbits (Menghi et al, 1995), monkeys (Jones et al, 2001) and horses .…”