Regulation of tyrosine hydroxylase activity in retinal cell suspensions: effects of potassium and 8-bromo cyclic AMP.
Regulation of tyrosine hydroxylase activity in retinal cell suspensions: effects of potassium and 8-bromo cyclic AMP.
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视网膜细胞悬浮液中酪氨酸羟化酶活性的调节：钾和 8-溴环 AMP 的作用。
DOI：
10.1016/0024-3205(82)90639-7
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发表时间：
1982
期刊：
影响因子：
6.1
通讯作者：
Marshburn,PB
中科院分区：
文献类型：
--
作者：
Iuvone,PM;Marshburn,PB
大鼠视网膜多巴胺(DA)神经元中的酪氨酸羟化酶(TH)在体内被光刺激激活。实验检测了膜电位的变化和环AMP依赖的蛋白磷酸化对这些视网膜神经元TH活性的影响。视网膜被分离成明显存活的细胞的悬浮液，以测试在没有跨突触影响的情况下，药物操纵TH活性的直接效果。为了测试膜电位变化对TH活性的影响，我们检测了去极剂钾的影响。细胞悬液在含有去极化浓度K+(52 MM)的林格氏液中孵育后，TH活性显著增加，提示膜去极化可能触发了一系列导致TH激活的分子事件。在细胞悬浮液中加入8-溴环AMP，这是一种已知的环状AMP类似物，在细胞外作用后激活环状AMP依赖的过程，导致TH的显著激活，与体外产生的环状AMP依赖的蛋白质磷酸化相媲美。这些数据支持膜电位在TH活性调节中起作用的假说，并表明依赖于环磷酸腺苷的磷酸化可以激活视网膜原位TH。悬浮液中视网膜细胞的明显活性表明，这种制备方法可能有助于研究突触调节机制。
Tyrosine hydroxylase (TH) contained in dopamine (DA) neurons of rat retina is activated in vivo as a consequence of photic stimulation. Experiments were conducted to test the effects of changes of membrane potential and of cyclic AMP-dependent protein phosphorylation on TH activity of these retinal neurons. Retinas were dissociated into suspensions of apparently viable cells to test the direct effects of pharmacological manipulations of TH activity in the absence of trans-synaptic influences. To test the effects of changes of membrane potential on TH activity we examined the effects of a depolarizing agent, potassium. Incubation of cell suspensions in Ringer's solution containing a depolarizing concentration of K+(52 mM) resulted in a significant increase of TH activity, suggesting that membrane depolarization may trigger a series of molecular events that leads to TH activation. Incubation of cell suspensions in the presence of 8-bromo cyclic AMP, a cyclic AMP analog that is known to activate cyclic AMP-dependent processes following extra-cellular application, resulted in a significant activation of TH that was comparable to that produced in vitro by cyclic AMP-dependent protein phosphorylation. These data support the hypothesis that membrane potential plays a role in the regulation of TH activity, and indicate that cyclic AMP-dependent phosphorylation can activate retinal TH in situ. The apparent viability of the retinal cells in suspension suggests that this preparation may be useful for studying synaptic regulatory mechanisms.
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兔视网膜和脉络膜中儿茶酚胺的鉴定和细胞定位。
DOI：
10.1111/j.1748-1716.1965.tb04153.x
发表时间：
1965
期刊：
Acta physiologica Scandinavica
影响因子：
--
作者：
J. Häggendal;T. Malmfors
通讯作者：
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影响因子：
5
作者：
C. Kamp;W. W. Morgan
通讯作者：
W. W. Morgan
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影响因子：
4.7
作者：
S. Kakiuchi;T. Rall;H. Mcilwain
通讯作者：
H. Mcilwain
GABA 能对暗适应大鼠体内光诱导多巴胺周转增加的影响
影响因子：
4.7
作者：
W. W. Morgan;C. Kamp
通讯作者：
C. Kamp
环AMP对大鼠脑体外儿茶酚胺合成的调节
影响因子：
64.8
作者：
Jane E. Harris;V. Morgenroth;Robert H. Roth;Ross J. Baldessarini
通讯作者：
Ross J. Baldessarini