title: Immunohistochemical study on Met-enkephalin-Arg-Gly-Leu-like immunoreactive nerve fibers in the rat adrenal medulla.
abstract: Met-enkephalin-Arg-Gly-Leu-like immunoreactivity was revealed in many nerve fibers as well as in chromaffin cells in the rat adrenal medulla. The immunoreactive nerve fibers were seen among and around chromaffin cells in the forms of punctate structures or varicose processes and they were characterized by numerous small clear vesicles mixed with several large granular vesicles. The nerve fibers formed synaptic contacts with both Met-enkephalin-Arg-Gly-Leu-like immunoreactive and non-immunoreactive chromaffin cells. The immunoreactive material in the nerves was generally confined to the granular cores. The present findings suggest that preproenkephalin A and its derivatives are produced in adrenal afferents which may be preganglionic cholinergic, and that they may play a significant role in the function of adrenal chromaffin cells.
mesh_terms: D000313:Adrenal Medulla / Q000378:metabolism* / Q000648:ultrastructure; D000818:Animals; D002799:Cholinergic Fibers / Q000502:physiology; D004744:Enkephalin, Methionine / Q000031:analogs & derivatives* / Q000378:metabolism; D004745:Enkephalins / Q000502:physiology; D007124:Immunoenzyme Techniques; D008297:Male; D008854:Microscopy, Electron; D009412:Nerve Fibers / Q000378:metabolism; D011498:Protein Precursors / Q000502:physiology; D051381:Rats
chemical_list: D004745:Enkephalins; D011498:Protein Precursors; D004744:Enkephalin, Methionine; C038498:enkephalin-Met, Arg(6)-Gly(7)-Leu(8)-Lys(9)-; C033660:preproenkephalin