Comparison of immunohistochemical localization of [Met5]enkephalin-Arg6-Gly7-Leu8, [Met5]enkephalin, neuropeptide Y and vasoactive intestinal polypeptide in the superior cervical ganglion of the rat.
The localization of [Met5]enkephalin-Arg6-Gly7-Leu8 and [Met5]enkephalin immunoreactivities was studied in the rat superior cervical ganglion. The distribution of these enkephalin-containing peptides in the ganglion was correlated to that of neuropeptide Y and vasoactive intestinal polypeptide. Three different populations of peptide-containing postganglionic neurons were demonstrated. (1) A minor population (10-20%) of principal neurons was immunoreactive for [Met5]enkephalin-Arg6-Gly7-Leu8 but not immunoreactive for neuropeptide Y nor vasoactive intestinal polypeptide. (2) The major population (about 50-70%) was immunoreactive for neuropeptide Y but not for [Met5]enkephalin-Arg6-Gly7-Leu8. (3) Few vasoactive intestinal polypeptide-immunoreactive principal neurons (less than 2% of all principal neurons) were observed in the ganglion. All vasoactive intestinal polypeptide-immunoreactive neurons were also immunoreactive for neuropeptide Y but not for [Met5]enkephalin-Arg6-Gly7-Leu8. [Met5]enkephalin-Arg6-Gly7-Leu8- and [Met5]enkephalin-immunoreactive nerve fibers had a similar distribution. These enkephalin immunoreactive nerve fibers were seen to enclose both neuropeptide Y-containing principal neurons and neurons devoid of neuropeptide Y immunoreactivity. Furthermore, there were enkephalin-immunoreactive fiber baskets around vasoactive intestinal polypeptide-immunoreactive neurons and sometimes also around solitary enkephalin-immunoreactive neurons. Previously reported diverse role of enkephalins in the rat superior cervical ganglion is supported by this study.
Karhula
T
T
Department of Anatomy, University of Helsinki, Finland.
D000818:Animals; D004745:Enkephalins / Q000378:metabolism*; D007150:Immunohistochemistry; D009412:Nerve Fibers / Q000276:immunology; D009478:Neuropeptide Y / Q000378:metabolism*; D011498:Protein Precursors / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D017783:Superior Cervical Ganglion / Q000502:physiology*; D014660:Vasoactive Intestinal Peptide / Q000378:metabolism*
D004745:Enkephalins; D009478:Neuropeptide Y; D011498:Protein Precursors; C029992:proenkephalin; D014660:Vasoactive Intestinal Peptide