Stimulation of 45Ca2+ efflux from rat pituitary by luteinizing hormone‐releasing hormone and other pituitary stimulants.
Stimulation of 45Ca2+ efflux from rat pituitary by luteinizing hormone‐releasing hormone and other pituitary stimulants.
复制标题
黄体生成素释放激素和其他垂体兴奋剂刺激大鼠垂体 45Ca2+ 流出。
DOI：
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发表时间：
1976
期刊：
影响因子：
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通讯作者：
J. Williams
中科院分区：
文献类型：
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作者：
J. Williams
1.将大鼠前垂体在含45 Ca 2+的培养基中孵育，用非放射性培养基灌注，并研究45 Ca 2+的流出。2.当使用来自过度切除大鼠的垂体时，在Ca 2+缓慢指数外排发生时向培养基中加入LH-RH，在LH释放增加的同时或之前，45 Ca 2+外排产生短暂增加。45 Ca 2+外排和LH释放的刺激显示出对LH-RH的类似浓度依赖性。3.增加培养基中K+浓度10倍也刺激45 Ca ~（2+）流出和LH释放。无钙培养基灌流降低了两个参数对LH‐RH的反应。4.当使用完整或甲状腺切除的雄性大鼠时，LH-RH仅诱导垂体45 Ca 2+流出量小幅增加。TRH增加甲状腺切除大鼠垂体45 Ca 2+流出，但只有一个小的影响时，垂体从完整或卵巢切除大鼠进行了研究。5.用雌二醇预处理卵巢切除大鼠可抑制随后由LH‐RH诱导的45 Ca 2+流出增加。6.由此得出结论，促分泌素诱导的45 Ca 2+流出量增加是由于细胞Ca 2+活性增加，推测其在刺激-分泌偶联中是活跃的。
1. Rat anterior pituitaries were incubated in medium containing 45Ca2+, superfused with non‐radioactive medium and the efflux of 45Ca2+ studied. 2. When pituitaries from overiectomized rats were used the addition of LH‐RH to the medium at a time when slow exponential efflux of Ca2+ was occurring produced a transient increase in 45Ca2+ efflux simultaneous with or before an increased release of LH. The stimulation of both 45Ca2+ efflux and LH release showed a similar concentration dependence on LH‐RH. 3. Increasing the K+ concentration of the medium tenfold also stimulated 45Ca2+ efflux and LH release. The response to LH‐RH of both parameters was reduced by superfusion with calcium‐free medium. 4. LH‐RH induced only a small increase in pituitary 45Ca2+ efflux when intact or thyroidectomized male rats were used. TRH increased 45Ca2+ efflux from thyroidectomized rat pituitaries but had only a small effect when pituitaries from intact or ovariectomized rats were studied. 5. Pretreatment of ovariectomized rats with oestradiol inhibited the subsequent increase in 45Ca2+ efflux induced by LH‐RH. 6. It is concluded that the secretagogue induced increase in 45Ca2+ efflux results from an increase in cellular Ca2+ activity which is presumably active in stimulus‐secretion coupling.