TY - JOUR T1 - The Effect of 6-Hydroxydopamine on Specific [<sup>3</sup>H]Ouabain Binding to Some Sympathetically Innervated Organs of the Cat JF - Molecular Pharmacology JO - Mol Pharmacol SP - 796 LP - 804 VL - 13 IS - 5 AU - VIRENDRA K. SHARMA AU - SHAILESH P. BANERJEE Y1 - 1977/09/01 UR - http://molpharm.aspetjournals.org/content/13/5/796.abstract N2 - To determine the distribution of (Na+ + K+)-ATPase at the sympathetic nerve endings of various organs of the cat, specific [3H]ouabain binding to microsomal preparations of different tissues was measured in either NaCl-treated or 6-hydroxydopamine-treated adult cats. Specific [3H]ouabain binding to microsomal preparations either decreased (salivary glands, heart, nictitating membrane, and vas deferens), increased (brain), or showed no change (kidney and spleen) following administration of 6-hydroxydopamine. The dissociation constants of [3H]ouabain, determined by Scatchard analysis, either decreased (heart and nictitating membrane), increased (salivary glands and vas deferens), or did not change (brain) as a result of the administration of 6-hydroxydopamine. More than 80% of the total number of specific [3H]ouabain binding sites in salivary glands, heart, nictitating membrane, and vas deferens were localized at the sympathetic nerve endings. These results are consistent with the hypothesis that (Na+ + K+)-ATPase located on the heart muscle cell membrane may be a part of the "pharmacological receptors" for ouabain and that the inhibition of (Na+ + K+)-ATPase found on the sympathetic nerve endings of heart muscle may be involved, in part, in the development of cardiac glycoside-induced cardiac arrhythmia. ER -