Expression of renin-angiotensin system components in the early bovine embryo.

The renin-angiotensin system (RAS), mainly associated with the regulation of blood pressure, has been recently investigated in female reproductive organs and the developing foetus. Angiotensin II (Ang II) influences oviductal gamete movements and foetal development, but there is no information about RAS in the early embryo. The aim of this study was to determine whether RAS components are present in the pre-implantation embryo, to determine how early they are expressed and to investigate their putative role at this stage of development.

Cellular localization of aquaporins along the secretory pathway of the lactating bovine mammary gland: an immunohistochemical study.

In this study we examined the cellular localization of aquaporins (AQPs) along the secretory pathway of actively lactating bovine mammary glands using immunohistochemistry. Mammary tissues examined included secretory ducts and acini, gland cisterns, teats, stromal and adipose tissues. Aquaporin 1 (AQP1) was localized in capillary endothelia throughout the mammary gland in addition to myoepithelial cells underlying teat duct epithelia.

Extracellular matrix of the corpus luteum.

The potential importance of the extracellular matrix to luteal formation and development, additional development in response to pregnancy hormones in some species, and luteal function and regression is possibly under-appreciated. Collagens I and III and fibronectin change dynamically during the formation of the corpus luteum and probably reflect the necessity for directional migration of cells in the establishment of a vascularized corpus luteum. Extracellular proteins may also be essential for the maintenance of luteal cell phenotype.