Effect of pertussis toxin on α 2 ‐adrenoceptors: decreased formation of the high‐affinity state for agonists
1984; Wiley; Volume: 172; Issue: 1 Linguagem: Inglês
10.1016/0014-5793(84)80881-9
ISSN1873-3468
AutoresJ. Adolfo García‐Sáinz, José L. Boyer, Thomas Michel, Diane Sawyer, Gary L. Stiles, Henrik Dohlman, Robert J. Lefkowitz,
Tópico(s)Ion channel regulation and function
ResumoAdministration of pertussis toxin to hamsters abolishes the α 2 ‐adrenergic inhibition of adenylate cyclase in their adipocytes. The toxin did not modify the number of adipocyte α 2 ‐adrenoceptors or their affinity for antagonists. In contrast, the affinity for agonists was significantly diminished in adipocyte membranes obtained from pertussis toxin‐treated hamsters as compared to the controls. This decrease in affinity was due to a significant diminution in the proportion of sites displaying the high‐affinity state for agonists. It is concluded that pertussis toxin induces a shift in the proportion of sites in high‐ and low‐affinity states for agonists towards the low‐affinity conformation.
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