Characterization of [3H]Ouabain Binding Sites in Human Brain, Platelet, and Erythrocyte |
| |
| Authors: | R Hauger H M D Luu F K Goodwin S M Paul |
| |
| Institution: | Clinical Neuroscience Branch, National Institutes of Health, Bethesda, Maryland, U.S.A.;Intramural Research Program, National Institute of Mental Health, National Institutes of Health, Bethesda, Maryland, U.S.A. |
| |
| Abstract: | 3H]Ouabain binding was investigated in membranes prepared from human brain, erythrocyte, and platelet. Scatchard analysis of 3H]ouabain binding to human hypothalamic membranes revealed a single class of noninteracting binding sites with an apparent affinity constant (KD) of 21 nM. Though the number of 3H]ouabain binding sites was lower in human platelets than in erythrocytes, both tissues exhibited a single class of high-affinity binding sites with an apparent KD similar to that found in human brain. Specific 3H]ouabain binding in basal ganglia tissue from patients with Huntington's disease was more than 50% lower than in tissue from age- and sex-matched controls. These results, along with previous findings in rat brain, suggest that high-affinity 3H]ouabain binding labels the neuronal form of Na, K-ATPase in human brain, and may prove useful in quantitating this enzyme in postmortem brain samples. |
| |
| Keywords: | Ouabain Na K-ATPase Central nervous system Huntington's disease |
|
|
