Expression of iNOS gene in macrophages stimulated with 17β-estradiol is regulated by free intracellular Ca2+
Expression of iNOS gene in macrophages stimulated with 17β-estradiol is regulated by free intracellular Ca2+
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DOI：
10.1139/o04-032
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发表时间：
2004-06-01
影响因子：
2.9
通讯作者：
Adedokun, OO
中科院分区：
文献类型：
--
作者：
Azenabor, AA;Yang, S;Adedokun, OO
17beta-Estradiol has potent Ca2+ ionophore capability and its signaling in macrophages is mediated through binding to surface and genomic receptors, resulting in transient nitric oxide (NO) elaboration. We decided to examine if the transient release of NO is due to Ca2+ influx pattern or the quenching effect of superoxide (O-2(-)) through peroxynitrite formation. Differential chelation of intracellular Ca2+ ([Ca2+]i) showed that NO generation was favored by [Ca2+]i concentration of 237 nM. Application of an estrogen receptor antagonist ICI 182 780 resulted in attenuation of estradiol mediated NO release. Studies directed at identifying the possible role of O-2(-) in the attenuation of NO showed no supportive evidence. Inhibition of extracellular Ca2+ channel or extracellular and intracellular Ca2+ channels showed data consistent with a case for optimum Ca2+ influx signal favoring iNOS gene expression, accompanied by an elevation in iNOS protein. These data show that Ca2+ influx pattern determines macrophage NO elaboration.
