@entity1 endometrium expresses specific kappa-opioid binding sites and their endogenous ligands, the dynorphins. In neural crest-derived tissues, kappa-opioids affect apoptosis, a phenomenon of major significance in endometrial stroma physiology. Our hypothesis was that endometrial kappa-opioids may play a role in endometrial stromal cell apoptosis. Thus, we examined the effect of the synthetic kappa-opioid agonist, @entity25838 , on the apoptotic rate of @entity1 endometrial stromal cells in primary culture. Apoptosis of endometrial stromal cells was elevated after 3 h exposure to 100 nmol/l @entity25838 , and remained elevated for up to 3 days. This effect was dose-dependent and was reversed by the general opioid antagonist, @entity1510 , suggesting that it is mediated via opioid receptors. In parallel, semi-quantitative Western blot and flow cytometry analysis showed that @entity25838 caused a rapid but transient up-regulation of Fas protein, suggesting that its effect on apoptosis is mediated by activation of the Fas/ @entity12 apoptotic pathway. Additionally, @entity25838 increased the content of the anti-apoptotic members of the @entity588 family of proteins, the @entity588 and @entity1836 , whereas it had no significant effect on the apoptosis-promoting homologues @entity589 , @entity1836 (S) and Bak. This implies that a transient survival mechanism is activated in stromal cells as a parallel rescue response to the apoptosis-inducing factor. In conclusion, our data suggest that endometrial opioid dynorphins may participate in the apoptotic processes related to @entity1478 during early pregnancy or menstruation.

The Fas/ XXXX apoptotic pathway is involved in kappa-opioid-induced apoptosis of @entity1 endometrial stromal cells.

@entity1 :: ('9606', 'Species') :: ['human', 'Human'] @entity589 :: ('581', 'Gene') :: ['Bax'] @entity588 :: ('596', 'Gene') :: ['Bcl-2'] @entity25838 :: ('MESH:C045444', 'Chemical') :: ['U69593'] @entity1836 :: ('598', 'Gene') :: ['Bcl-x(L)', 'Bcl-x'] @entity1510 :: ('MESH:D009270', 'Chemical') :: ['naloxone'] @entity12 :: ('356', 'Gene') :: ['FasL'] @entity1478 :: ('MESH:D014591', 'Disease') :: ['endometrial tissue remodelling']
@entity12 :: (356,Gene) :: ['FasL']
