Pharmacological characterisation of native somatostatin receptors in AtT-20 mouse tumour corticotrophs

Abstract

1. The mouse corticotroph tumour cell line AtT-20 is a useful model to investigate the physiological role of native somatostatin (SRIF, Somatotropin release inhibitory factor) receptor subtypes (sst 1-sst 5). The objective of this study was to characterise the pharmacological features and the functional effects of SRIF receptors expressed by AtT-20 cells using radioligand binding and cAMP accumulation. 2. [ 125I]LTT-SRIF-28, [ 125I]CGP 23996, [ 125I]Tyr 10-cortistatin-14 and [ 125I]Tyr 3-octreotide labelled SRIF receptor binding sites with high affinity and in a saturable manner (B max = 315, 274, 239 and 206 fmol mg -1, respectively). [ 125I]LTT-SRIF-28 labels significantly more sites than ..