Immunocytochemical and in situ hybridization studies of the distribution of calbindin D(9k) in the bovine placenta throughout pregnancy

Nikitenko, Leonid; Morgan, Geoffrey; Kolesnikov, Sergei I.; Wooding, F. B.Peter

Abstract

The fetus must transport considerable and increasing amounts of calcium across the placental trophoblast epithelium to support growth and development and bone formation. Active calcium transport across epithelia has been shown to correlate with calbindin D(9k) or (28k) content. This study examined the distribution of calbindin D(9k) (9CBP) protein and mRNA during pregnancy in the bovine placenta to determine its possible role in calcium transport in this system. The immunocytochemical results show 9CBP in an increasing percentage of interplacentomal uninucleate trophoblast cells until, at term, all show a level at least eight times that of any other placental cell. There is a similar, although smaller, rise in their 9CBP mRNA content. The mature interplacentomal binucleate cell (~5% of the total) contains no 9CBP at any stage of pregnancy. In interplacentomal uterine epithelium, 9CBP protein and mRNA decrease to zero in late pregnancy but the glands maintain constant low levels throughout. In the placentome trophoblast, uninucleate cells show insignificant amounts but binucleate cells (15-20% of the total trophoblast cells) contain considerable levels of both 9CBP protein and mRNA, as do all the uninucleate uterine epithelial cells. The placentomal binucleate cells show peak values at mid-pregnancy; the placentomal uterine epithelium shows only small changes in levels in the second half of pregnancy. Increase in fetal calcium demand in the second half of pregnancy therefore correlates with a major increase in 9CBP only in the interplacentomal trophoblast, as we have also shown in the sheep and goat, indicating an important role for this region in active calcium transport by the ruminant placenta. The 9CBP is distributed uniformly in the cytosol and nucleoplasm, supporting a role in facilitated diffusion of calcium through the cell rather than a vesicular shuttle system.

Citation

Nikitenko, L., Morgan, G., Kolesnikov, S. I., & Wooding, F. B. (1998). Immunocytochemical and in situ hybridization studies of the distribution of calbindin D(9k) in the bovine placenta throughout pregnancy. Journal of Histochemistry and Cytochemistry, 46(5), 679-688. https://doi.org/10.1177/002215549804600513

• Journal Article Type: Article
• Publication Date: Jan 1, 1998
• Deposit Date: May 3, 2022
• Journal: Journal of Histochemistry and Cytochemistry
• Print ISSN: 0022-1554
• Electronic ISSN: 1551-5044
• Publisher: SAGE Publications
• Peer Reviewed: Peer Reviewed
• Volume: 46
• Issue: 5
• Pages: 679-688
• DOI: https://doi.org/10.1177/002215549804600513
• Public URL: https://hull-repository.worktribe.com/output/3571109
• Publisher URL: https://journals.sagepub.com/doi/pdf/10.1177/002215549804600513