Substance P (SP) is a neuropep-tide widely distributed in the central and peripheral nervous system as trophic factor. It was detected also in the Von Ebner's (VE) gland of the tongue. In this study, the formative ef­fect of(SP) was investigated by caus­ing temporary denervation of VE gland.
Twelve adult albino rats were used in this study. They were divided into three groups. In each rat, the left glossopharyngeal nerve was crushed on the left side and the right side was used as control .After two , four and eight weeks , specimens from the posterior third of the tongue were ex-
amined for histological structure, PAS reaction and the immunohistochemi-cal reaction of (SP) and the results were recorded.
It was observed that the integrity and normal structure and the excreto­ry function of the gland depends on intact innervation that supplies a neu-ropeptide trophic substance e.g. sub­stance P.