Effect of parasympathectomy on the histochemical maturation of myoepithelial cells of the rat sublingual salivary gland.

This effect of parasympathectomy was assessed by fluorescent microscopy using nitrobenzoxadiazole-phallacidin, which is known for its specific binding to actin filaments. Resection of the chorda tympani within 48 h after birth inhibited the normal formation of actin in the myoepithelial cells and the maturation of myoepithelial cells. The effect of denervation decreased progressively if the operation was delayed. Denervation 30 days after birth had no effect on development and differentiation of myoepithelial cells. Moreover, the procedure produced no histochemical changes in the myoepithelial cells in mature rats, even two months later. These findings suggest that the parasympathetic innervation is closely involved in the maturation of myoepithelial cells. Further, its involvement is limited to the first 48 h after birth, during which it exerts its neurotrophic effect on the myoepithelial cells present in all the acinar buds.