Somatostatin receptor 1-5 (SSTR1-5) (SSTR1-5)

Somatostatin receptors (SSTR1–5) are a family of five distinct G protein-coupled receptors (GPCRs) that mediate the inhibitory effects of the peptide hormone somatostatin (SRIF) (UniProt, 2024). These receptors are widely distributed across the central nervous system, endocrine glands, and gastrointestinal tract, where they play a pivotal role in suppressing the secretion of various hormones, including growth hormone, insulin, and glucagon (StatPearls, 2023). In clinical medicine, SSTRs are significant therapeutic targets because they are frequently overexpressed in neuroendocrine tumors (NETs) and pituitary adenomas (PubMed, PMID: 30651271). Synthetic somatostatin analogs (SSAs) such as octreotide and lanreotide primarily target SSTR2 to manage symptoms of acromegaly and carcinoid syndrome, while newer multi-receptor ligands like pasireotide offer broader affinity across SSTR1, 2, 3, and 5 (NIH, 2023). Beyond hormone suppression, SSTRs are utilized in diagnostic imaging (e.g., 68Ga-DOTATATE PET) and peptide receptor radionuclide therapy (PRRT) to deliver targeted radiation to tumor cells (Journal of Nuclear Medicine, 2021).

Other names

SSTR1-5SRIF receptorsSomatostatin receptor types 1 to 5SST1, SST2, SST3, SST4, SST5SS1R, SS2R, SS3R, SS4R, SS5R

Agonism of somatostatin receptors leads to the inhibition of adenylyl cyclase, reduction of intracellular cAMP levels, and modulation of potassium and calcium channels, ultimately suppressing hormone release and cellular growth (IUPHAR/BPS Guide to Pharmacology, 2023).