VIP and related peptides induce rapid homologous desensitization in the human lymphoma SUP T1 cell line |
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| Authors: | P Robberecht P De Neef M Waelbroeck M Tastenoy J Christophe |
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| Institution: | Department of Biochemistry and Nutrition, Medical School, Université Libre de Bruxelles, Belgium. |
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| Abstract: | Incubation of human SUP T1 lymphoblasts with VIP, helodermin and related peptides induced homologous desensitization within 5 min as indicated by: 1) a secondary decrease in cellular cyclic AMP levels, even in the presence of phosphodiesterase inhibitors, 2) a reduced capacity of cells to bind 125I]helodermin, 3) decreased helodermin stimulation of adenylate cyclase activity in membranes, and 4) unaffected NaF- and GppNH]p-stimulated adenylate cyclase activities. The desensitizing ability of all peptides correlated with their efficacy to occupy cell receptors, except for D-Phe2]VIP, a partial VIP agonist with low intrinsic activity, that did not desensitize. |
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