Cellular mechanism for norepinephrine suppression of pineal photoreceptor-like cell differentiation in rat pineal cultures.
Cellular mechanism for norepinephrine suppression of pineal photoreceptor-like cell differentiation in rat pineal cultures.
复制标题
去甲肾上腺素抑制大鼠松果体培养物中松果体感光样细胞分化的细胞机制。
DOI：
10.1016/0012-1606(92)90298-u
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发表时间：
1992
影响因子：
2.7
通讯作者：
M. Araki
中科院分区：
文献类型：
--
作者：
M. Araki
虽然大鼠松果体是一个内分泌器官，没有光感受器活性，但新生大鼠的松果体在体外培养时含有可分化为具有视紫红质免疫反应性（Rho-I）的杆状细胞。去甲肾上腺素（NE）以剂量依赖性方式减少Rho-I细胞的数量，即使在20 nM时也具有相当大的效果。当在体外培养，松果体去除到产后第4天分化成Rho-I细胞的程度相同，在第1天（新生儿），但在第5天去除的那些表现出急剧减少的分化Rho-I细胞的数量。这表明，要么松果体细胞situsin失去了他们的潜力，分化的第5天或亚群的细胞参与通常消失在松果体年龄超过5天。NE的效果进行了检查，在新生儿松果体的文化，在9天的培养期内的不同阶段给药1或2天。NE在早期培养阶段存在于培养基中时是最有效的，并且如果仅在培养第7天之后存在则无效。这表明假定的松果体光感受器可能只在有限的时间内对NE敏感，并且一旦它们在此期间暴露于NE，它们就受到不可逆的影响，可能退化。这些细胞同样受到钾离子浓度低至15 mM的严重影响，这表明NE可能作用于肾上腺素受体以改变膜特性。5-羟色胺免疫反应细胞，另一种细胞类型（内分泌）中发现的文化，似乎是由NE调节的一个单独的机制。NE以可逆的方式抑制5-羟色胺细胞的过程延伸，而KCl没有这种作用。这些发现进一步证明，神经递质可能在调节发育中的神经系统中发挥重要作用，而不是传递信号。
Although the rat pineal is an endocrine organ and has no photoreceptor activity, pineals from neonatal rats contain cells that can differentiate into rod-like cells with rhodopsin immunoreactivity (Rho-I), when culturedin vitro. Norepinephrine (NE) reduces the number of Rho-I cells in a dose-dependent manner and has a considerable effect even at 20 nM. When culturedin vitro, pineals removed up to Postnatal Day 4 differentiated into Rho-I cells to the same extent as did those removed at Day 1 (neonatal), but those removed at Day 5 showed a sharp reduction in the number of differentiated Rho-I cells. This suggests that either pineal cellsin situlose their potential to differentiate by Day 5 or the subpopulation of cells involved normally disappears in pineals older than Day 5. The effect of NE was examined in cultures of neonatal pineals by administering it for 1 or 2 days at different stages during a 9-day culture period. NE was most effective when present in the culture medium at an early culture phase and was not efficacious if present only later than Culture Day 7. This indicates that presumptive pineal photoreceptors may become sensitive to NE only for a limited period and that once they are exposed to NE within this period they are irreversibly affected, possibly to degenerate. These cells are similarly and severely affected by potassium ion concentrations as low as 15 mM, suggesting that NE may act at the adrenoreceptor to modify the membrane properties. Serotonin-immunoreactive cells, another cell type (endocrine) found in the cultures, appeared to be regulated by NE by a separate mechanism. NE suppresses process extension by serotonin cells in a reversible manner, and KCl does not have this effect. These findings further evidence that neurotransmitters may have essential roles, other than the transmission of signals, in modulating the developing nervous system.
DOI：
10.1073/pnas.85.17.6556
发表时间：
1988-09-01
影响因子：
11.1
作者：
HAHN, JS;AIZENMAN, E;LIPTON, SA
通讯作者：
LIPTON, SA