Effect of brefeldin A on melatonin secretion of chick pineal cells.
Effect of brefeldin A on melatonin secretion of chick pineal cells.
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布雷菲德菌素 A 对鸡松果体细胞褪黑素分泌的影响。
DOI：
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发表时间：
2001
期刊：
影响因子：
--
通讯作者：
Y. Fukada
中科院分区：
文献类型：
--
作者：
T. Hirota;S. Kagiwada;T. Kasahara;T. Okano;M. Murata;Y. Fukada
褪黑激素由松果体以昼夜节律方式分泌。众所周知，褪黑激素的合成表现出昼夜节律，反映了血清素 N-乙酰转移酶 (NAT) 活性的每日变化，而褪黑激素的整体分泌需要一个细胞释放过程，但人们对此知之甚少。为了研究高尔基体来源的囊泡在释放中的可能参与，我们检测了布雷菲德菌素 A (BFA)（一种高尔基体介导的分泌的可逆抑制剂）对培养的鸡松果体细胞褪黑激素分泌的影响。我们在此表明，BFA 治疗可完全分解高尔基体并减少褪黑激素的分泌。然而，在更详细的时程实验中，只有在去除 BFA 并同时重新组装高尔基体后才能观察到褪黑激素分泌的抑制。这种对褪黑激素分泌的抑制并不伴随着褪黑激素在细胞中的积累。这些观察结果表明，鸡松果体褪黑激素的释放独立于高尔基体衍生的囊泡，并表明去除 BFA 后褪黑激素的合成受到抑制。通过测量褪黑激素合成酶的活性和mRNA水平，我们发现BFA的去除在蛋白质水平上特异性抑制NAT活性。另一方面，BFA 不会导致调节褪黑激素分泌昼夜节律的小鸡松果体振荡器发生可检测的相移。这里提出的结果表明，高尔基体介导的囊泡运输既不参与褪黑激素的释放，也不参与昼夜节律振荡器的计时机制，而是有助于 NAT 活性的调节。
Melatonin is secreted from the pineal gland in a circadian manner. It is well established that the synthesis of melatonin shows a diurnal rhythm reflecting a daily change in serotonin N-acetyltransferase (NAT) activity, and the overall secretion of melatonin requires a cellular release process, which is poorly understood. To investigate the possible involvement of Golgi-derived vesicles in the release, we examined the effect of brefeldin A (BFA), a reversible inhibitor of Golgi-mediated secretion, on melatonin secretion of cultured chick pineal cells. We show here that treatment with BFA completely disassembles the Golgi apparatus and reduces melatonin secretion. In more detailed time course experiments, however, the inhibition of melatonin secretion is only observed after the removal of BFA in parallel with the reassembly of the Golgi apparatus. This inhibition of melatonin secretion is not accompanied by accumulation of melatonin in the cells. These observations indicate that chick pineal melatonin is released independently of the Golgi-derived vesicles, and suggest inhibition of melatonin synthesis after the removal of BFA. By measuring the activities and mRNA levels of melatonin-synthesizing enzymes, we found that the removal of BFA specifically inhibits NAT activity at the protein level. On the other hand, BFA causes no detectable phase-shift of the chick pineal oscillator regulating the circadian rhythm of melatonin secretion. The results presented here suggest that the Golgi-mediated vesicular transport is involved in neither the melatonin release nor the time-keeping mechanism of the circadian oscillator, but rather contributes to the regulation of NAT activity.
鸟类松果体，昼夜节律振荡器的脊椎动物模型系统：通过光、第二信使和大分子合成对昼夜节律进行细胞调节。
DOI：
10.1016/b978-0-12-571145-6.50010-8
发表时间：
1989
期刊：
Recent progress in hormone research
影响因子：
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作者：
Takahashi,JS;Murakami,N;Nikaido,SS;Pratt,BL;Robertson,LM
通讯作者：
Robertson,LM