@entity855 -evoked increase in intracellular XXXX via the P2Y receptor in proliferating @entity291 trophoblast cells.

@entity1603 @entity856 @entity593 @entity460 @entity141 @entity857 @entity5747 @entity291 @entity855
@entity291 trophoblasts actively proliferate to elongate blastocysts before implantation. The trophoblast at this stage secretes cytokines and starts to differentiate into an endocrine cell (binucleate cell) for successful pregnancy. Intracellular @entity460 ([ @entity141 ]i) may act as a second messenger in the trophoblast response. In this study, we investigated [ @entity141 ]i signals in a @entity291 trophoblast cell line (BT-1) using @entity593 fluorescence. We found that an application of @entity855 (> or =1 microM) induced a transient increase in [ @entity141 ]i in BT-1 cells. The @entity855 -induced increase was not affected by the removal of extracellular @entity141 , but was suppressed by @entity5747 (100 microM), an antagonist of P2 receptors. Pretreatment with pertussis toxin (0.1 or 1 microg/ml) partially inhibited the response to @entity855 . The order of potency to increase [ @entity141 ]i was @entity855 = @entity856 > @entity857 . @entity855 -induced [ @entity141 ]i responses preferentially occurred in cells at the periphery of the colony. The reduced responses at the center of the colony were associated with an increase in cell density and decrease in @entity1603 incorporation. These results indicated that @entity855 stimulated P2Y receptors coupled to pertussis toxin-sensitive and -insensitive G proteins, leading to an increase in [ @entity141 ]i as a result of release of @entity141 from intracellular stores in BT-1 cells. The occurrence of @entity855 -induced [ @entity141 ]i signals depended on the cell confluence and reflected the high proliferative activity of the trophoblast cell population.
