Inhibition by selenium compounds of catecholamine secretion due to inhibition of Ca2+ influx in cultured bovine adrenal chromaffin cells.
Inhibition by selenium compounds of catecholamine secretion due to inhibition of Ca2+ influx in cultured bovine adrenal chromaffin cells.
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DOI：
10.1254/jphs.fp0060204
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发表时间：
2006
影响因子：
3.5
通讯作者：
Y. Uezono;Y. Toyohira;N. Yanagihara;A. Wada;K. Taniyama
中科院分区：
文献类型：
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作者：
Y. Uezono;Y. Toyohira;N. Yanagihara;A. Wada;K. Taniyama
硒是人体必需的微量金属元素，但大剂量的硒会对人体产生不良影响。我们研究了硒化合物，亚硒酸钠（Na_2SeO_3）和硒酸钠（Na_2SeO_4）对培养的牛肾上腺嗜铬细胞分泌儿茶酚胺的影响。亚硒酸钠处理嗜铬细胞72，48，和24小时引起蛋白质和儿茶酚胺含量下降，与细胞损伤，在浓度超过30，300，和300 μ M，分别。用亚硒酸钠的亚毒性条件（<100 μ M，48小时）处理的细胞用于进一步的实验。亚硒酸钠处理48 h抑制卡巴胆碱（CCh）诱导的儿茶酚胺分泌的浓度依赖性和非竞争性的方式，而它不影响高K+和藜芦碱诱导的儿茶酚胺分泌。亚硒酸钠（100 μ M）不影响CCh和藜芦碱诱导的22 Na+内流，而化合物仅抑制CCh诱导的45 Ca 2+内流，但不影响高K+和藜芦碱诱导的45 Ca 2+内流。硒酸钠，即使在较高的浓度（1000 μ M）没有影响任何刺激诱导的儿茶酚胺分泌和45Ca2+内流。因此，亚硒酸钠可能特异性地发挥不利作用，例如由于抑制Ca2+内流而抑制生理刺激诱导的肾上腺嗜铬细胞的儿茶酚胺分泌。
Selenium is an essential trace metal element, whereas large doses of selenium exert adverse effects to the human body. We examined the effects of selenium compounds, sodium selenite (Na2SeO3) and sodium selenate (Na2SeO4), on catecholamine secretion from cultured bovine adrenal chromaffin cells. Treatment of chromaffin cells with sodium selenite for 72, 48, and 24 h caused decreases in protein and catecholamine contents, in association with cell damage, at concentrations over 30, 300, and 300 microM, respectively. The cells treated with subtoxic conditions (<100 microM, 48 h) of sodium selenite were used for further experiments. Sodium selenite treatment for 48 h inhibited carbachol (CCh)-induced catecholamine secretion in a concentration-dependent and non-competitive manner, while it did not affect high K+- and veratridine-induced catecholamine secretion. Sodium selenite (100 microM) did not affect CCh- and veratridine-induced 22Na+ influx, while the compound inhibited 45Ca2+ influx induced only by CCh, but not high K+ and veratridine. Sodium selenate even at higher concentrations (1000 microM) did not affect any stimulus-induced catecholamine secretion and 45Ca2+ influx. Thus, sodium selenite may specifically exert adverse effects, such as inhibition of physiological stimulus-induced catecholamine secretion from adrenal chromaffin cells due to inhibition of Ca2+ influx.