Pharmacological Characterizations of Adrenergic Receptors in Human Adipocytes

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Abstract

Three types of adrenergic receptors, beta, alpha-1, and alpha-2, were identified in human adipocytes, isolated from properitoneal adipose tissue, using both the binding of radioactive ligands and the effects of adrenergic agents on receptor-specific biochemical responses. Adrenergic binding studies showed the following results: [3H]dihydroalprenolol binding (beta adrenergic) Bmax 280 fmol/mg protein, KD 0.38 nM; [3H]para-aminoclonidine binding (alpha-2 adrenergic) Bmax 166 fmol/mg protein, KD 0.49 nM; [3H]WB 4101 binding (alpha-1 adrenergic) Bmax 303 fmol/mg protein, KD 0.86 nM. In adipocytes from subcutaneous adipose tissue, [3H]dihydroergocryptine binding indicated the presence of alpha-2 but not alpha-1 receptors.

Authors

Thomas W. Burns, Paul E. Langley, Boyd E. Terry, David B. Bylund, Brian B. Hoffman, Michael D. Tharp, Robert J. Lefkowitz, J. Adolfo García-Saínz, John N. Fain