Localization and quantitation of hyaluronan and sulfated glycosaminoglycans in the tissues and intraluminal fluid of the pig oviduct

Abstract

Glycosaminoglycans (GAGs), hyaluronan (HA) and heparan sulfate (HS) were localized in the pre- and post-ovulatory oviducts of inseminated and control (non-inseminated) sows using biotinylated HA-binding protein (HABP) and anti-syndecan antibodies respectively. In addition, the concentrations of HA and total sulfated GAGs (S-GAGs) were measured in fluid collected in vivo from either a selected tubal segment (isthmus or ampulla) or from the contralateral whole oviduct (WO) of non-inseminated sows during proestrus–metoestrus. HA was localized in the lamina propria of the entire oviduct, but epithelial HA-labelling was only present in the sperm reservoir (utero-tubal junction–adjacent isthmus) in control and inseminated sows. In contrast, immunolabelling for HS proteoglycans (HSPGs, syndecans) was present on the entire epithelial lining, both pre and post ovulation and in both sow groups. Both HA and S-GAGs could be detected in the intraluminal fluid. Concentrations varied among sows and segments; those of the S-GAGs being higher (P<0.05) than that of HA. Mean levels of S-GAGs and HA tended to increase in the fluid collected from isthmus and ampulla during standing oestrus. Fluid levels from the WO, however, fluctuated less during the collection period. Major statistical differences were not present, owing to the large variation seen between animals. The results confirm, however, that GAGs are present in the pig oviduct. The conspicuous localization in the sperm reservoir and the tendency to higher levels in the fluid during pre-ovulatory oestrus support the hypothesis that GAGs play a role in modulating sperm viability and capacitation during sperm transport in the pig oviduct.