VIP and related peptides induce rapid homologous desensitization in the human lymphoma SUP T1 cell line.
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 Gpp[NH]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.
Robberecht
P
P
Department of Biochemistry and Nutrition, Medical School, Université Libre de Bruxelles, Belgium.
De Neef
P
P
Waelbroeck
M
M
Tastenoy
M
M
Christophe
J
J
D015056:1-Methyl-3-isobutylxanthine / Q000494:pharmacology; D000262:Adenylyl Cyclases / Q000378:metabolism; D002460:Cell Line; D002462:Cell Membrane / Q000201:enzymology; D000242:Cyclic AMP / Q000378:metabolism*; D006165:Guanylyl Imidodiphosphate / Q000494:pharmacology; D006801:Humans; D036341:Intercellular Signaling Peptides and Proteins; D007700:Kinetics; D008223:Lymphoma; D010455:Peptides / Q000378:metabolism; D011964:Receptors, Gastrointestinal Hormone / Q000187:drug effects / Q000502:physiology*; D018005:Receptors, Vasoactive Intestinal Peptide; D014660:Vasoactive Intestinal Peptide / Q000378:metabolism / Q000494:pharmacology*; D014688:Venoms / Q000378:metabolism
D036341:Intercellular Signaling Peptides and Proteins; D010455:Peptides; D011964:Receptors, Gastrointestinal Hormone; D018005:Receptors, Vasoactive Intestinal Peptide; D014688:Venoms; D006165:Guanylyl Imidodiphosphate; D014660:Vasoactive Intestinal Peptide; C040442:heliodermin; D000242:Cyclic AMP; D000262:Adenylyl Cyclases; D015056:1-Methyl-3-isobutylxanthine