Estrogens modulate the density of opioid receptors in selected brain areas; however, it is not clear whether they exert such an effect directly on the cells which express the opioid receptors. Therefore, we analyzed the binding of [3H]-diprenorphine in human neuroblastoma cells stably transfected with the estrogen receptor cDNA (SK-ER3 cell line). A 16-hour exposure of these cells with 1 nM 17beta-estradiol induces a progressive morphological differentiation which appears clearly established 6 days after the suspension of the treatment. The binding of [3H]-diprenorphine was then measured immediately after the exposure to 17beta-estradiol (16 h) as well as 6 days later. The results shows that the number of opioid receptors in SK-ER3 cells is unaffected at 16 h but appears significantly reduced at 6 days. This effect is blocked by the estrogen antagonist ICI-182780, and is coincident to a decrease of the inhibitory effect of morphine on cyclic AMP accumulation. Binding experiments performed using selective ligands suggest that the micro subclass of opioid receptors is down-regulated by estradiol in SK-ER3 cells.
Decrease of the number of opioid receptors and of the responsiveness to morphineduring neuronal differentiation induced by 17beta-estradiol in estrogen receptor-transfected neuroblastoma cells (SK-ER3) / R. Maggi, Z.Q. Ma, F. Pimpinelli, A.C. Maggi, L. Martini. - In: NEUROENDOCRINOLOGY. - ISSN 0028-3835. - 69:1(1999 Jan), pp. 54-62.
Decrease of the number of opioid receptors and of the responsiveness to morphineduring neuronal differentiation induced by 17beta-estradiol in estrogen receptor-transfected neuroblastoma cells (SK-ER3)
R. MaggiPrimo
;F. Pimpinelli;A.C. MaggiPenultimo
;L. MartiniUltimo
1999
Abstract
Estrogens modulate the density of opioid receptors in selected brain areas; however, it is not clear whether they exert such an effect directly on the cells which express the opioid receptors. Therefore, we analyzed the binding of [3H]-diprenorphine in human neuroblastoma cells stably transfected with the estrogen receptor cDNA (SK-ER3 cell line). A 16-hour exposure of these cells with 1 nM 17beta-estradiol induces a progressive morphological differentiation which appears clearly established 6 days after the suspension of the treatment. The binding of [3H]-diprenorphine was then measured immediately after the exposure to 17beta-estradiol (16 h) as well as 6 days later. The results shows that the number of opioid receptors in SK-ER3 cells is unaffected at 16 h but appears significantly reduced at 6 days. This effect is blocked by the estrogen antagonist ICI-182780, and is coincident to a decrease of the inhibitory effect of morphine on cyclic AMP accumulation. Binding experiments performed using selective ligands suggest that the micro subclass of opioid receptors is down-regulated by estradiol in SK-ER3 cells.Pubblicazioni consigliate
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