[125I]Tyr10-cortistatin14 labels all five somatostatin receptors

Abstract

The recently cloned rat preprocortistatin, which shows homology to the preprosomatostatin peptide, is thought to be enzymatically cleaved to cortistatin14 (CST14) similarly to somatostatin14 (SRIF14). High structural similarity of cortistatin14 compared to SRIF14 suggested binding properties to somatostatin receptors similar to SRIF14. In the present study, we expressed stably the five human somatostatin receptor subtypes (hsst1-hsst5) in CCL39 cells (Chinese hamster lung fibroblast cells). The receptors were labelled with an iodinated analogue of CST14 ([125I]Tyr10-cortistatin14, [125I]Tyr10-CST) to establish the pharmacological profile of hsst1-hsst5 sites labelled with [125I]Tyr10-CST. In..