title: A direct contact of substance P-containing nerve fibers with pupillary sphincter muscles of the rat: an immunohistochemical analysis.
mesh_terms: D000818:Animals; D007124:Immunoenzyme Techniques; D008854:Microscopy, Electron; D009132:Muscles / Q000502:physiology* / Q000648:ultrastructure; D009412:Nerve Fibers / Q000502:physiology*; D011680:Pupil / Q000648:ultrastructure; D051381:Rats; D013373:Substance P / Q000502:physiology*
chemical_list: D013373:Substance P