title: Interaction of vasoactive intestinal peptide with a cell line (HeLa) derived from human carcinoma of the cervix: binding to specific sites and stimulation of adenylate cyclase.
abstract: The binding of vasoactive intestinal peptide (VIP) and its effect on cyclic AMP production were assessed in HeLa cells. The binding of [125I]VIP is a moderately rapid process, reversible, saturable, specific and dependent on temperature. Virtually no inactivation of the peptide is observed after 2 h of exposure to the cells. At 15 degrees C, the binding data obtained at steady state are compatible with the existence of two classes of binding sites: a first class with a Kd of 2.4 nM and low binding capacity (1.5 X 10(5) sites/cell) and a second class with a Kd of 100 nM and a high binding capacity (4.9 X 10(6) sites/cell). Secretin is eight times less potent than VIP in competing with 125I VIP but glucagon, insulin and somatostatin are inactive. VIP-induced stimulation of cyclic AMP production depends on time and temperature and is potentiated by a phosphodiesterase inhibitor. A concentration of VIP as low as 10(-10) M is able to stimulate adenylate cyclase. Half-maximal stimulation is observed at 10(-9) M and maximal stimulation (4 times above basal levels) at 10(-8) M VIP. Secretin is an agonist of VIP but exhibits a 1000 times lower potency with respect to adenylate cyclase activation. Glucagon, insulin and somatostatin do not show any effect. The presence of high-affinity binding sites and high sensitivity and specificity of adenylate cyclase for VIP in HeLa cells provide a good model to study the role of this peptide on cell proliferation and differentiation.
mesh_terms: D000262:Adenylyl Cyclases / Q000378:metabolism*; D001665:Binding Sites; D001667:Binding, Competitive; D000242:Cyclic AMP / Q000096:biosynthesis*; D005768:Gastrointestinal Hormones / Q000494:pharmacology*; D006367:HeLa Cells / Q000378:metabolism; D006801:Humans; D006863:Hydrogen-Ion Concentration; D011956:Receptors, Cell Surface / Q000378:metabolism; D018005:Receptors, Vasoactive Intestinal Peptide; D013696:Temperature; D014660:Vasoactive Intestinal Peptide / Q000378:metabolism / Q000494:pharmacology*
chemical_list: D005768:Gastrointestinal Hormones; D011956:Receptors, Cell Surface; D018005:Receptors, Vasoactive Intestinal Peptide; D014660:Vasoactive Intestinal Peptide; D000242:Cyclic AMP; D000262:Adenylyl Cyclases