Somatostatin Receptor (SSTR)

Somatostatin receptors (SSTRs) are a family of G protein-coupled receptors (GPCRs) that mediate the effects of somatostatin, a cyclic peptide hormone involved in regulating neurotransmission, hormone secretion, and cell proliferation. There are five known subtypes: SSTR1, SSTR2, SSTR3, SSTR4, and SSTR5. These subtypes are differentially distributed throughout the central nervous system (CNS) and peripheral tissues. They regulate multiple physiological processes including hormone secretion, neuronal activity, and cell proliferation. SSTR expression increases significantly in certain pathological states like neuroendocrine tumors, making them important diagnostic markers and therapeutic targets. Synthetic analogs are used for treating acromegaly and neuroendocrine tumors.

Other names

Somatostatin receptorsSST receptorsSSTR1SSTR2SSTR3SSTR4SSTR5

Activation typically inhibits adenylyl cyclase through inhibitory G-proteins (Gαi/o), reducing cAMP levels. Some subtypes also modulate ion channels or activate phosphotyrosine phosphatases or MAPK pathways to control cell cycle progression and apoptosis.