Molecular Pharmacology, Vol 15, 35-42, Copyright © 1979 by the American Society for Pharmacology and Experimental Therapeutics

Regeneration of [³H]Ouabain Binding to (Na⁺ + K⁺)-ATPase in Chemically Sympathectomized Cat Peripheral Organs

¹ Department of Pharmacology and Toxicology, University of Rochester School of Medicine and Dentistry, Rochester, New York 14642

Regeneration of specific binding of [³H]ouabain in particulate fractions and Na⁺-dependent [³H]norepinephrine uptake in tissue slices from salivary gland, heart, spleen and nictitating membrane were measured in control and chemically sympathectomized cats. Regeneration of ouabain binding was relatively rapid in salivary gland and relatively slow in heart and nictitating membrane particulate fractions. Similarly, recovery of norepinephrine uptake was relatively rapid in salivary gland and relatively slow in heart and spleen slices. Thus rates of reappearance of ouabain binding and norepinephrine uptake appear to be similar in separate organs. Kinetic analyses of ouabain binding show that the return of ouabain binding sites in regenerating sympathetic nerve endings is due to augmentation of density of binding sites. The norepinephrine uptake and ouabain binding in salivary glands degenerated to a similar extent 24 hours after administration of 6-hydroxydopamine. These results support the idea that a major fraction of ouabain binding sites in several sympathetically innervated organs is localized at the sympathetic nerve terminals.