The functional regeneration of syncytiotrophoblast in cultured explants of term placenta

Abstract

We have investigated the functional characteristics of term human placental villous explants kept in long-term (7-11 days) culture. Fragments of placental villous tissue (approximately 5-10 mg wet wt) were cultured in supplemented CMRL-1066 culture medium for up to 11 days. After the first day of culture, the syncytiotrophoblast appeared vacuolated and eventually degenerated. However, a new syncytiotrophoblast developed by day 4, being indistinguishable from that of a fresh placenta by 11 days. Release of human chorionic gonadotrophin increased and activity of lactate dehydrogenase in culture medium decreased with culture time. Transport variables were measured over the first 7 days of culture. Basal (86)Rb efflux was reduced with time in culture and was inhibited by Ba2+, suggesting the efflux was mediated by K+ channels. At all stages of culture, (86)Rb efflux was stimulated by ATP, hyposmotic medium, and ANG II. A complex pattern of efflux changes with culture time and type of stimulator was observed, suggesting that several compartments of the tissue contributed to stimulated efflux. This culture system provides opportunities for studies of chronic regulation of placental function.

Effects of Prenatal Cocaine Exposure on Human Pregnancy and Postpartum

“…Basic studies on placental villous explant viability; analysis of morphology, metabolic activity, glucose consumption, lactate production and protein expression have shown that placental explants remain functional for ~2 weeks following an initial degeneration with recovery after ~48 h of culture [62,63]. A detailed understanding of the extent to which placental explant integrity is comparable to the physiological, in vivo situation and how the process of post-ischemic recovery in vitro affects tissue integrity and viability is lacking [62][63][64].…”

“…A detailed understanding of the extent to which placental explant integrity is comparable to the physiological, in vivo situation and how the process of post-ischemic recovery in vitro affects tissue integrity and viability is lacking [62][63][64]. In particular, the significance of the interval between delivery and initiation of explant culture is poorly understood.…”

Placental nutrient supply and fetal growth

“…As regards cellular homeostasis, Birdsey et al, (1999) showed that hypoosmotic challenge of the syncytiotrophoblast resulted in activation of both K + , and anion, conductances (Birdsey et al, 1999) suggesting that they are involved in maintenance of cell volume. K + efflux is also stimulated by angiotensin and ATP, and there is evidence that the latter effects specifically the Ca 2+ sensitive K + channels (Clarson et al, 2002;Siman et al, 2001). In relation to regulation of secretory processes, recent data show that specific K + channel blockers inhibit the secretion of human chorionic gonadotrophin from syncytiotrophoblast (Williams et al, 2007).…”

Carbon Monoxide Inhibits Hypoxia/Reoxygenation-Induced Apoptosis and Secondary Necrosis in Syncytiotrophoblast

“…40 All reagents, unless otherwise indicated, were purchased from Sigma-Aldrich Ltd. (Oakville, ON, Canada).…”