1. [Dependence of kinetic constants of intact human lymphocyte beta2-adrenoreceptors on the nature of the radioligands used].
- Author
-
Krasnikova TL, Korichneva IL, and Radiukhin VA
- Subjects
- Adrenergic beta-Antagonists, Alprenolol, Binding, Competitive, Ethylmaleimide, Humans, Isoproterenol, Kinetics, Lymphocytes drug effects, Pindolol analogs & derivatives, Propanolamines, Radioligand Assay, Receptors, Adrenergic, beta drug effects, Temperature, Lymphocytes metabolism, Receptors, Adrenergic, beta metabolism
- Abstract
An analysis of human peripheral blood intact mononuclear lymphocyte beta 2-adrenoreceptors showed that the hydrophilic radioligand 3H-CGP-12177 binds at various temperatures only to surface receptors. The density of receptors as determined by the binding of the lipophilic antagonist 125I-CYP at 37 degrees C is 2 times as high as that at 4 degrees C. The affinity of lymphocyte beta 2-adrenoceptors for 1-isoproterenol measured by the labeled ligand displacement at low (4 degrees C) temperatures is by two or three orders of magnitude higher than that at 37 degrees C. The thiol-alkylating agent, N-ethylmaleimide (NEM) causes oppositely directed changes in the density of beta 2-adrenoceptors on intact lymphocytes depending on their original density. NEM increases the affinity of beta 2-adrenoreceptors for the hormone (1.5-12-fold). The state and regulation of human peripheral blood lymphocyte beta 2-adrenoreceptors depend on the hormonal status of patients at the moment of blood sample collection.
- Published
- 1989