TY - JOUR T1 - Pharmacological characterization of type B cholecystokinin binding sites on the human JURKAT T lymphocyte cell line. JF - Molecular Pharmacology JO - Mol Pharmacol SP - 615 LP - 620 VL - 39 IS - 5 AU - M F Lignon AU - N Bernad AU - J Martinez Y1 - 1991/05/01 UR - http://molpharm.aspetjournals.org/content/39/5/615.abstract N2 - Recent studies have demonstrated the presence and the regulatory function of some neuropeptides in the immune system. In the present study, we have used labeled cholecystokinin (26-33) amide to characterize high affinity cholecystokinin (CCK) binding sites on a human JURKAT lymphoma cell line. Binding was temperature dependent, saturable, and specific. Analysis of the data demonstrated a single class of binding sites with high affinity for the ligand (Kd approximately 3.2 +/- 0.5 x 10(-11) M) and a binding capacity of 0.42 fmol/10(6) cells (approximately 300 sites/cell). These CCK binding sites displayed a typical CCK-B pharmacological profile, established by use of several agonists and antagonists selective for the CCK receptor types, namely compound L-364,718, the Merck CCK antagonist selective for the peripheral CCK receptor (CCK-A), and compound L-365,260, the Merck CCK antagonist selective for the central CCK receptor (CCK-B). The CCK cyclic analogue recently developed in our laboratory that is highly selective for the CCK-B receptor (i.e., JMV320) also showed high affinity for the CCK receptor on the JURKAT cell line. The presence of CCK-B-like binding sites on a lymphoid cell line could provide a useful model for pharmacological characterization of CCK-B binding sites and could contribute to a better understanding of their regulation. ER -