Female reproductive tract fluids: composition, mechanism of formation and potential role in the developmental origins of health and disease

Abstract

The oviduct and uterus provide the environments for the earliest stages of mammalian embryo development. However, little is known about the mechanisms that underlie the formation of oviduct and uterine fluids, or the extent to which the supply of nutrients via these reproductive tract tissues matches the nutrient requirements of early embryos. After reviewing our limited knowledge of these phenomena, a new experimental paradigm is proposed in which the epithelia lining the endosalpinx and endometrium are seen as the final components in a supply line that links maternal diet at one end and embryo uptake of nutrients at the other. When considered in this way, the oviduct and uterine epithelia become, for a few days, potentially the most critical maternal tissues in the establishment of a healthy pregnancy. In fulfilling this 'gatekeeper' role, female reproductive tract fluids have a key role in the 'developmental origins of health and disease' concept.

Oviductal secretion and gamete interaction

“…The oviductal fluid contains amino acids, proteins, simple, and complex carbohydrates, ions, lipids, and phospholipids. Some of these components are metabolic substrates, such as lactate, pyruvic acid, amino acids, and glucose, whose levels differ from those present in the uterine fluid and the serum (Leese 1988, Leese et al 2008, Hugentobler et al 2010. Experimental evidence indicated that ion concentrations in oviductal fluid also differ from those of serum, suggesting that the oviductal epithelium modulates ion levels (Leese 1988, Leese et al 2008, Hugentobler et al 2010.…”

“…The presence of adequate levels of bicarbonateand calcium seems to be essential in regulating sperm capacitation, motility, and acrosome reaction (Rodriguez-Martinez 2007, Leese et al 2008, Abouhaila & Tulsiani 2009, Lishko et al 2012. Hyaluronan and sulfated glycosaminoglycans, such as heparin, have been detected in oviductal fluid from different mammalian species (Kawakami et al 2000, Tienthai et al 2000, Bergqvist & Rodríguez-Martínez 2006.…”

“…Transuded serum proteins, such as albumin and HDLs, are found in the oviductal fluid and would be involved in the cholesterol efflux from sperm membrane during capacitation (Travis & Kopf 2002, Leese et al 2008, Abou-haila & Tulsiani 2009). …”

“…The oviduct synthesizes and secretes proteins whose functions have not been clarified with certainty (Leese et al 2008, Killian 2011. Notorious differences in the proteomic profiles of the oviduct between follicular and luteal phases of the reproductive cycle in pig were Oviductal secretion R3 reported (Seytanoglu et al 2008).…”

Cumulus oophorus T cells: a possible source of follicular fluid G-CSF, biomarker predictive for embryo implantation in IVF/ICSI cycles

“…Another possibility could be that FF G-CSF provides the embryo with crucial information on how to repair itself (16). The FF itself could be involved in the complex dialogue that leads to implantation and could transmit messages directly to the fallopian tube and to the uterus in fertile patients (28). However, it is difficult to imagine the FF cytokines, which are known to act locally, influencing directly the receptivity of the uterus, which is far from the ovary.…”