Coexistence of somatostatin receptor subtypes in the human neuroblastoma cell line LA-N-2.

Five distinct human somatostatin receptor subtypes have recently been cloned and characterized. Previous studies have suggested that these receptor subtypes might display coexistent localization, based on in situ hybridization or immunoblockage experiments. Here we provide evidence for coexistence of somatostatin receptor subtypes 2 and 5 in the human neuroblastoma cell line LA-N-2, using a combined approach with RT-PCR and receptor binding studies with somatostatin analogues. Somatostatin receptor subtypes simultaneously localized to a single cell might serve distinct functions in terms of targeting to different intraneuronal compartments or subtype specificity against so far unidentified somatostatin-related peptides.