l-NAME, a nitric oxide synthase inhibitor, increases the protein expression of both executioner and inhibitor of apoptosis in the placental bed of mid-to-late pregnant rats.

The involvement of nitric oxide (NO) signaling in apoptosis was examined in the placental bed of mid-to-late pregnant rats. Pregnant rats were treated with l-NAME, a nitric oxide synthase inhibitor, by subcutaneous infusion for 48 h before the examination at day 13.5, 17.5 or 21.5. l-NAME induced apoptosis in the placental bed to a limited extent at days 13.5 and 17.5, but not at day 21.5. When the placental bed was examined at day17.5, the protein expression of both executioner (C-Cas3) and inhibitor (XIAP) of apoptosis was increased by l-NAME, but they did not co-localized with apoptosis. It was presumed that placental bed apoptosis induced by l-NAME is regulated through the expression of both executioner and inhibitor, possibly involving protein S-nitrosylation. This article is protected by copyright. All rights reserved.