Figure 2.

Percentage of TUNEL-positive nuclei in untreated versus GTN-treated villous explants after a 6-hour H/R insult or after a 6-hour incubation in 5% O₂. Treatment of explants with GTN significantly inhibited syncytiotrophoblast apoptosis after a 6-hour exposure to H/R. Relatively low levels of apoptosis were observed in control explants incubated under normoxic conditions (5% O₂) with or without GTN. Asterisk indicates a significant difference (P < 0.001) between untreated explants after the 6-hour H/R exposure versus untreated explants after 3 hours of hypoxia alone. The H/R-exposed group consisted of explants isolated from 13 placentas whereas the group exposed to 5% O₂ consisted of explants isolated from five placentas. Data are presented as means ± SE.