Methionine-enkephalin immunoreactivity in Merkel cell dense-core granules of nude mice sinus hair. A post-embedding immunogold electron-microscopic study.
The ultra-immunocytochemical technique applied in the present study revealed the occurrence of methionine-enkephalin (met-enkephalin)-like substance in the dense-core granules of Merkel cells of nude mice sinus hair. Incubation of ultra-thin sections of sinus hair with met-enkephalin antisera conjugated with gold particles showed specific association of gold particles on the dense-core granules of the Merkel cells. Gold particles were heavily and specifically located on the dense-core granules as well as in the adjacent cytoplasm. Dense-core granules of degenerating Merkel cells also exhibit met-enkephalin immunoreactivity. The nerve terminals associated with the Merkel cell did not show met-enkephalin immunoreactivity. Therefore, it is concluded that a met-enkephalin-like substance is present and stored in nude mice Merkel cell dense-core granules and it might act as a neurotransmitter or neuromodulator which could be involved in the functioning of the cell. Non-osmicated tissue should be used to locate this substance because of the possibility of cross-linkage of the amino acid sequence with osmium tetroxide.
Department of Physiology, Faculty of Medicine, Chinese University of Hong Kong, Shatin, N.T.
S B
SB
Chew
P Y
PY
Leung
D001078:APUD Cells / Q000737:chemistry / Q000648:ultrastructure*; D000818:Animals; D003594:Cytoplasmic Granules / Q000737:chemistry*; D004744:Enkephalin, Methionine / Q000032:analysis*; D007150:Immunohistochemistry; D051379:Mice; D008807:Mice, Inbred BALB C; D008819:Mice, Nude / Q000033:anatomy & histology / Q000378:metabolism*; D008854:Microscopy, Electron / Q000379:methods; D014738:Vibrissae / Q000166:cytology*
D004744:Enkephalin, Methionine