In this study we characterized calcitonin (CT) receptors in human neuroblastoma IMR 32 cells. Saturation binding assays indicated that [125I]-human CT bound with high affinity to IMR 32 cell membranes (K(d)=253.6 pM; B(max)=3.84 fmol/mg protein). In competition binding studies, human adrenomedullin displayed high affinity for these sites (IC50=30 nM) whereas human α calcitonin-gene related peptide (αCGRP; IC50=145 nM) and human amylin (IC50=415 nM) showed lower affinity. These peptides increased cAMP levels in viable cells; the relative potencies were: human CT > human adrenomedullin > human αCGRP ≥ human amylin. The expression of mRNA coding for the published sequences of the human calcitonin receptor and of the human calcitonin receptor-like receptor was evaluated by reverse transcriptase- polymerase chain reaction. Electrophoretic analysis did not confirm the occurrence of mRNA coding for the above mentioned receptors in these cells. This study suggests the presence of a novel, putative CT receptor in IMR 32 cells. Copyright (C) 1999 Elsevier Science Ireland Ltd.
Spampinato S., Falcucci B., Cacciaguerra S., Campana G., Murari G. (1999). Characterization of a putative calcitonin receptor in IMR 32 human neuroblastoma cells. NEUROSCIENCE LETTERS, 273(3), 167-170 [10.1016/S0304-3940(99)00661-8].
Characterization of a putative calcitonin receptor in IMR 32 human neuroblastoma cells
Spampinato S.;Cacciaguerra S.;Campana G.;Murari G.
1999
Abstract
In this study we characterized calcitonin (CT) receptors in human neuroblastoma IMR 32 cells. Saturation binding assays indicated that [125I]-human CT bound with high affinity to IMR 32 cell membranes (K(d)=253.6 pM; B(max)=3.84 fmol/mg protein). In competition binding studies, human adrenomedullin displayed high affinity for these sites (IC50=30 nM) whereas human α calcitonin-gene related peptide (αCGRP; IC50=145 nM) and human amylin (IC50=415 nM) showed lower affinity. These peptides increased cAMP levels in viable cells; the relative potencies were: human CT > human adrenomedullin > human αCGRP ≥ human amylin. The expression of mRNA coding for the published sequences of the human calcitonin receptor and of the human calcitonin receptor-like receptor was evaluated by reverse transcriptase- polymerase chain reaction. Electrophoretic analysis did not confirm the occurrence of mRNA coding for the above mentioned receptors in these cells. This study suggests the presence of a novel, putative CT receptor in IMR 32 cells. Copyright (C) 1999 Elsevier Science Ireland Ltd.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
