@article {Kaniucki488, author = {M D Kaniucki and J C Elverdin and M A Luchelli-Fortis and C J Perec and F J Stefano}, title = {Sympathetic and parasympathetic nerves regulate postsynaptic alpha-2 adrenoceptor in salivary glands.}, volume = {239}, number = {2}, pages = {488--493}, year = {1986}, publisher = {American Society for Pharmacology and Experimental Therapeutics}, abstract = {The effects of sympathetic denervation or parasympathetic decentralization on the inhibitory effects of postsynaptic alpha-2 adrenoceptors were studied in the submaxillary and the sublingual gland of the rat. Chronic sympathetic denervation enhanced by a factor of 10 the potency of clonidine to inhibit the secretory responses of the submaxillary gland to either norepinephrine or methacholine. In denervated glands, clonidine (1 microgram/kg), reduced markedly the response to norepinephrine, but potentiated this response in control glands. Blockade of postsynaptic alpha-2 adrenoceptors with idazoxan (3 micrograms/kg) enhanced the secretory responses of denervated glands to norepinephrine. Parasympathetic decentralization also potentiated the inhibitory effects of the alpha-2 agonists. In the submaxillary gland the potency of guanabenz to decrease the secretory response to methacholine was increased by a factor of 30. Supersensitivity to the inhibitory effects of clonidine was also observed in parasympathetically decentralized sublingual glands. Parasympathetic decentralization increased the maximum binding site of [3H]clonidine binding by about 50\% in both the submaxillary and sublingual glands. No changes in KD were detected. This surgical procedure also increased the maximum binding site of [3H]prazosin binding in submaxillary glands. The present findings show clearly that interruption of either branch of the autonomic nervous system induces supersensitivity of the inhibitory response mediated through postsynaptic alpha-2 adrenoceptors. The enhanced inhibitory activity could mask alpha-1 adrenoceptor supersensitivity after postganglionic sympathetic denervation.}, issn = {0022-3565}, URL = {https://jpet.aspetjournals.org/content/239/2/488}, eprint = {https://jpet.aspetjournals.org/content/239/2/488.full.pdf}, journal = {Journal of Pharmacology and Experimental Therapeutics} }