A tion of drugs on denervated myoepithelial cells of salivary glands.

1. The pressure in the ducts of the two submaxillary glands was recorded in anaesthetized dogs in which either the superior cervical ganglion had been removed or the chorda-lingual nerve had been cut on one side, 17-30 days earlier. Noradrenaline, adrenaline, phenylephrine, acetylcholine and methacholine were injected to produce pressure rises attributed to contraction of myoepithelial cells.2. After sympathectomy increased pressure responses were obtained with all the drugs, but particularly with noradrenaline. Cocaine increased the effect of noradrenaline on the normal gland but slightly less than sympathectomy.3. Parasympathetic decentralization increased the pressure effects of acetylcholine and methacholine, and in most cases also increased those of the sympathomimetic drugs.4. It is concluded that the myoepithelial cells of this gland normally receive motor impulses from both divisions of the autonomic nervous system, and that many, if not all, of the cells are innervated by both. Disconnecting the gland from the central nervous system by either pathway causes supersensitivity of the classical post-junctional type, and sympathetic ganglionectomy causes in addition a pre-junctional sensitization.