Abstract
The possibility that opioid peptides and noradrenaline co-exist not only in the desheathed bundle of bovine splenic nerve which contains ~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 D 2O-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 β-hydroxylase activity supports the conclusion that opioid peptides are stored in the primary population of large dense-cored 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.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.