Immunohistochemical localization of glial cell line-derived neurotrophic factor and its receptor Ret in the rat sweat gland.
Glial cell line-derived neurotrophic factor (GDNF) was initially identified as a neurotrophic factor for dopaminergic neurons but its effects are not restricted to nervous tissue. It is reported that GDNF-induced intercellular signaling is necessary for the normal development of a variety of non-neural tissues. In this study, immunoreactivities of both GDNF and its functional receptor Ret were evaluated in normal adult rat sweat gland by light and electron microscopy. Ret was found in the epithelial cells of the excretory duct and the coiled secretory terminal of the sweat gland. Electron microscopic observation of the secretory epithelium showed that Ret immunoreactivity is localized in the basal area of the secretory cells, facing myoepithelial cells, but it was not observed in the basal infolding or in the apical region of these cells. On the other hand, GDNF was observed in most myoepithelial cells of the coiled secretory portion of the sweat gland and in a small number of nerve fibers innervating the gland. Although the GDNF-containing nerve fibers cannot be negated as a source of the ligand for Ret in the secretory cells, the finding that GDNF and Ret are localized face to face in adjoining cells in the sweat gland implies another novel trophic role of GDNF in this tissue.
Yoshida
Tomohiro
T
Department of Anatomy and Histology, Kurume University School of Medicine, Kurume 830-0011, Japan.
D000818:Animals; D051100:Glial Cell Line-Derived Neurotrophic Factor; D051097:Glial Cell Line-Derived Neurotrophic Factor Receptors; D007150:Immunohistochemistry; D016253:Microscopy, Immunoelectron; D009414:Nerve Growth Factors / Q000032:analysis* / Q000502:physiology; D011518:Proto-Oncogene Proteins / Q000032:analysis*; D051096:Proto-Oncogene Proteins c-ret; D051381:Rats; D017208:Rats, Wistar; D020794:Receptor Protein-Tyrosine Kinases / Q000032:analysis*; D013545:Sweat Glands / Q000737:chemistry* / Q000648:ultrastructure
C495041:Gdnf protein, rat; D051100:Glial Cell Line-Derived Neurotrophic Factor; D051097:Glial Cell Line-Derived Neurotrophic Factor Receptors; D009414:Nerve Growth Factors; D011518:Proto-Oncogene Proteins; D051096:Proto-Oncogene Proteins c-ret; D020794:Receptor Protein-Tyrosine Kinases; C495001:Ret protein, rat