Taylor P, Rieger F, Greene L A
Brain Res. 1980 Jan 27;182(2):383-96. doi: 10.1016/0006-8993(80)91196-8.
The development of acetylcholinesterase (AChE) activity and the distribution of this enzyme among its multiple forms was studied in both tissue extracts and dissociated cell cultures of chick paravertebral sympathetic ganglia. In agreement with previous findings, total AChE (expressed either per ganglion or per microgram protein) increased in vivo between the time of formation of the paravertebral chain (embryonic day 7; E7) to hatching (E20-E21). After this time, enzyme activity changed much more slowly. Sucrose gradient sedimentation analysis of AChE in ganglia of post-hatching chicks revealed multiple forms of AChE with S values of approximately 6.5, 11 and 19.5. Developmental studies showed that 6.5 S and 11 S forms are present as early as day E7. Much of the pre-hatching increase in total AChE is due to increased levels of the 6.5 S form of the enzyme. By hatching, this form comprised approximately 85-90% of the total AChE activity. In contrast, during the first week after hatching, the activity of the 11 S form increased several-fold while that of the 6.5 S remained approximately unchanged. The 19.5 S form, which is thought to be associated with the synaptic membrane, was not detected prior to day E17 and reached adult levels (2-3% of total AChE activity) by the first week after hatching. Development of AChE was also studied in dissociated cell cultures of embryonic ganglia. Essentially all the AChE activity in such cultures was found to be associated with the neurons. Total AChE activity of cultured E11 ganglia increased in a pattern which was both qualitatively and quantitatively similar to that which occurred in vivol. Furthermore, it was found that development of both the 6.5 and 11 S forms of AChE took place in vitro. In cultures of E8, E11, E15 and E19 ganglia, the distribution of activity between the two forms after various times in vitro was similar to that which was found for in vivo ganglia at an equivalent embryonic stage. Such changes were not affected by the elimination of nonneuronal cells from the cultures. Two aspects of in vitro development, however, differed from that which occurred in vivo. First, an increase in 11 S AChE did not occur at ages equivalent to the first week post-hatching. Second, the 19.5 S form did not develop (even after several weeks) in cultures of E8, E11 and E15 ganglia, nor was this form (which was removed during dissociation of the ganglia) regenerated in cultures of E19 ganglia. Such findings suggest that the pattern of development of AChE and its multiple forms in chick sympathetic neurons is in part intrinsically programmed into these cells at an early stage of development as well as in part regulated by extrinsic signals that these cells receive from their chemical and cellular environment.
在鸡椎旁交感神经节的组织提取物和离体细胞培养物中，研究了乙酰胆碱酯酶（AChE）活性的发育及其在多种形式间的分布。与先前的研究结果一致，总AChE（以每个神经节或每微克蛋白质表示）在椎旁链形成时（胚胎第7天；E7）至孵化时（E20 - E21）在体内增加。在此之后，酶活性变化更为缓慢。对孵化后雏鸡神经节中AChE进行蔗糖梯度沉降分析，发现AChE有多种形式，其沉降系数（S值）约为6.5、11和19.5。发育研究表明，早在E7天就存在6.5 S和11 S形式。孵化前总AChE的增加主要是由于该酶6.5 S形式水平的升高。到孵化时，这种形式约占总AChE活性的85 - 90%。相比之下，在孵化后的第一周，11 S形式的活性增加了几倍，而6.5 S形式的活性大致保持不变。19.5 S形式被认为与突触膜相关，在E17天之前未被检测到，到孵化后第一周达到成年水平（占总AChE活性的2 - 3%）。还在胚胎神经节的离体细胞培养物中研究了AChE的发育。基本上发现这种培养物中的所有AChE活性都与神经元相关。培养的E11神经节的总AChE活性以一种在质量和数量上与体内发生的情况相似的模式增加。此外，发现AChE的6.5 S和11 S形式的发育都在体外发生。在E8、E11、E15和E19神经节的培养物中，体外培养不同时间后两种形式之间的活性分布与在相同胚胎阶段的体内神经节中发现的情况相似。这种变化不受从培养物中去除非神经元细胞的影响。然而体外发育的两个方面与体内发生的情况不同。第一，在相当于孵化后第一周的年龄时，11 S AChE没有增加。第二，在E8、E11和E15神经节的培养物中，19.5 S形式没有发育（即使经过数周），在E19神经节的培养物中也没有再生这种形式（在神经节解离过程中被去除）。这些发现表明，鸡交感神经元中AChE及其多种形式的发育模式部分在发育早期就内在地编程到这些细胞中，部分受这些细胞从其化学和细胞环境接收的外在信号调节。
