Klein R L, Wilson S P, Dzielak D J, Yang W H, Viveros O H
Neuroscience. 1982;7(9):2255-61. doi: 10.1016/0306-4522(82)90135-x.
The possibility that opioid peptides and noradrenaline co-exist not only in the desheathed bundle of bovine splenic nerve which contains approximately 98% sympathetic C-fibers, but also in the population of large dense-cored noradrenergic vesicles from these fibers, has been investigated. The primary fraction of large dense-cored vesicles which can be prepared at about 85% purity has been further subjected to density gradient and fractional centrifugation procedures, including D2O-loading and unloading on modified second gradients, in an attempt to separate any minor population of particles which potentially could contain opioid peptides and contaminate the large dense-cored vesicle fraction. Measurement of opioid peptides, noradrenaline, dopamine and dopamine beta-hydroxylase activity supports the conclusion that opioid peptides are stored in the primary population of large dense-cord vesicles per se, rather than in a minor population of contaminating particles from cells other than sympathetic C-fibers. This conclusion has implications for exocytotic release and the physiological role of the opioid peptides intra- and extra-neuronally. Nerve vesicle opioid peptides have a size less than 5000 daltons, in contrast to the high proportion of large peptides containing enkephalin sequences in the bovine adrenal medulla.
人们已经研究了阿片肽和去甲肾上腺素不仅共存于牛脾神经的脱鞘束（其中约98%为交感C纤维）中，而且还共存于这些纤维的大致密核心去甲肾上腺素能囊泡群体中的可能性。可制备纯度约为85%的大致密核心囊泡的主要部分，进一步进行密度梯度和分级离心程序，包括在改良的第二梯度上加载和卸载重水，以试图分离任何可能含有阿片肽并污染大致密核心囊泡部分的少量颗粒群体。对阿片肽、去甲肾上腺素、多巴胺和多巴胺β-羟化酶活性的测量支持了这样的结论：阿片肽本身储存在大致密核心囊泡的主要群体中，而不是储存在来自交感C纤维以外细胞的少量污染颗粒中。这一结论对阿片肽在神经元内和神经元外的胞吐释放及生理作用具有重要意义。与牛肾上腺髓质中含有脑啡肽序列的大肽比例较高形成对比的是，神经囊泡阿片肽的大小小于5000道尔顿。
