Insulin stimulates choline acetyltransferase activity in cultured embryonic chicken retina neurons.
Insulin stimulates choline acetyltransferase activity in cultured embryonic chicken retina neurons.
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胰岛素刺激培养的胚胎鸡视网膜神经元中的胆碱乙酰转移酶活性。
DOI：
10.1073/pnas.84.21.7463
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发表时间：
1987
影响因子：
11.1
通讯作者：
Peterson,SW
中科院分区：
文献类型：
--
作者：
Kyriakis,JM;Hausman,RE;Peterson,SW
研究了胰岛素对在限定培养基中培养的鸡胚视网膜神经元中胆碱乙酰转移酶（ChoAcT;乙酰辅酶A：胆碱O-乙酰转移酶，EC 2.3.1.6）的出现的影响。在最低水平的胰岛素（1 ng/ml）的存在下，ChoAcT活性随着培养时间的推移而增加。观察到成分确定培养基中的胰岛素浓度（1-100 ng/ml）与ChoAcT活性的增加速率和最大达到水平之间的对应关系。最大ChoAcT活性是2- 3倍更大的细胞培养在100 ng的胰岛素/ml的存在下比在1 ng的胰岛素/ml的存在下培养的细胞。为了引起最大的ChoAcT活性，仅在培养期的前4天在培养基中需要100 ng/ml的胰岛素，此时胰岛素可以降低至维持水平（10 ng/ml）而不影响ChoAcT活性。在7天的培养期间进行的胰岛素结合试验显示，无论在培养期间培养基中的胰岛素浓度如何，细胞表面胰岛素受体在培养的4至7天之间减少了约90%。这种胰岛素结合的降低对应于观察到的ChoAcT活性对胰岛素的敏感性降低。我们的研究结果表明，胰岛素在介导鸡胚视网膜胆碱能分化中发挥作用。
The effect of insulin on the appearance of the enzyme choline acetyltransferase (ChoAcT; acetyl-CoA:choline O-acetyltransferase, EC 2.3.1.6) in embryonic chicken retina neurons cultured in defined medium was studied. In the presence of a minimal level of insulin (1 ng/ml), ChoAcT activity increased with time in culture. A correspondence between the insulin concentration in the defined medium (1-100 ng/ml) and both the rate of increase and maximum attained level of ChoAcT activity was observed. Maximal ChoAcT activity was 2- to 3-fold greater in cells cultured in the presence of 100 ng of insulin per ml than in cells cultured in the presence of 1 ng of insulin per ml. To elicit maximum ChoAcT activity, insulin at 100 ng/ml was required in the medium for only the first 4 days of the culture period, at which time insulin could be reduced to maintenance levels (10 ng/ml) without affecting ChoAcT activity. Insulin binding assays performed during a 7-day culture period revealed that irrespective of the insulin concentration in the medium during culture, cell-surface insulin receptors decreased by approximately 90% between 4 and 7 days in culture. This decrease in insulin binding corresponded to the observed decrease in the sensitivity of ChoAcT activity to insulin. Our findings suggest that insulin plays a role in mediating cholinergic differentiation in the embryonic chicken retina.