title: Species variability in the expression of met- and leu-enkephalin-like immunoreactivity in mammalian Merkel cell dense-core granules. A light- and electron-microscopic immunohistochemical study.
abstract: Immunogold staining failed to show met-enkephalin immunoreactivity in the Merkel cell dense-core granules of rats when examined by electron microscopy, but showed gold particle staining in the Merkel cell dense-core granules of mice and nude mice. Merkel cells of hamster, guinea pig, rabbit, cat and dog were also examined using a similar method, and different antisera dilutions. Immunogold particles were consistently found in the dense-core granules of mice and nude mice at all antisera dilutions, but not in the other species, except in the dog, where a very low labelling response was encountered. Merkel cells from skin touch domes or sinus hair follicles, did not exhibit any difference in peptide expression as far as met-enkephalin immunoreactivity was concerned. In addition, all species studied, including mice and nude mice, did not show leu-enkephalin immunoreactivity in their Merkel cell dense-core granules. It is concluded that species variability in peptide expression occurs in the Merkel cell dense-core granules, and may be closely related to the different methodologies used.
authors.affiliation: Department of Physiology, Faculty of Medicine, Chinese University of Hong Kong, Shatin, N.T.
authors.forename: S B
authors.initials: SB
authors.lastname: Cheng Chew
authors.forename: P Y
authors.initials: PY
authors.lastname: Leung
mesh_terms: D000818:Animals; D002415:Cats; D006224:Cricetinae; D003594:Cytoplasmic Granules / Q000378:metabolism / Q000648:ultrastructure; D004285:Dogs; D004743:Enkephalin, Leucine / Q000378:metabolism*; D004744:Enkephalin, Methionine / Q000031:analogs & derivatives* / Q000378:metabolism; D006168:Guinea Pigs; D006197:Hair / Q000166:cytology / Q000378:metabolism* / Q000648:ultrastructure; D007150:Immunohistochemistry; D008297:Male; D051379:Mice; D016253:Microscopy, Immunoelectron; D011817:Rabbits; D013045:Species Specificity
chemical_list: C024693:enkephalin-Met, like substances; D004744:Enkephalin, Methionine; D004743:Enkephalin, Leucine