INDUCTION OF TYROSINE-HYDROXYLASE IN THE RAT SUBSTANTIA-NIGRA BY LOCAL INJECTION OF FORSKOLIN
INDUCTION OF TYROSINE-HYDROXYLASE IN THE RAT SUBSTANTIA-NIGRA BY LOCAL INJECTION OF FORSKOLIN
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DOI：
10.1002/jnr.490300219
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发表时间：
1991-10-01
影响因子：
4.2
通讯作者：
FAUCONBIGUET, N
中科院分区：
文献类型：
--
作者：
LEVIEL, V;GUIBERT, B;FAUCONBIGUET, N
将福司可林(FSK)局部注射到麻醉大鼠黑质(SN)。注射后一天(24小时和36小时)，酪氨酸羟化酶(TH)活性在同侧尾状核(CN)内没有改变，但在该结构中局部增加。注射后24小时，黑质TH(TH-mRNA)信使RNA的量也增加。然而，TH蛋白的含量在SN和同侧CN都没有局部改变。此外，CN和SN中多巴胺与其第一代谢物的比值降低，表明多巴胺能黑质细胞的活动减少。尽管TH基因转录启动，但蛋白质合成没有增加，这可能是药物抑制多巴胺能细胞的结果。这些结果证实，在体内，TH的诱导是cAMP依赖的，并表明TH基因的活性与黑质中的多巴胺能细胞的活性并不是严格耦合的。
Forskolin (FSK) was locally injected into the substantia nigra (SN) of anesthetised rats. The day after injection (24 and 36 hr), tyrosine hydroxylase (TH) activity increased locally in this structure but remained unmodified in the ipsilateral caudate nucleus (CN). The amount of messenger RNA for TH (TH-mRNA) was also increased in the SN 24 hr after the injection. However, TH protein content was modified neither locally in the SN nor in the ipsilateral CN. In addition, the decrease of the ratio between dopamine and its first metabolite in the CN and the SN suggested a decreased activity of the dopaminergic nigral cells. The absence of increase of the protein synthesis in spite of the fact that TH-gene transcription was initiated could be the consequence of the inhibition of dopaminergic cells by the drug. These results confirm that, in vivo, TH induction is cAMP-dependent and demonstrate that the TH-gene activity is not strictly coupled to the activity of dopaminergic cells in the SN.