Somatostatin receptor type 5 (SSTR5) (SSTR5)

Somatostatin receptor type 5 (SSTR5) is a member of the G protein-coupled receptor (GPCR) superfamily, specifically the Class A rhodopsin-like family, which mediates the diverse inhibitory actions of the peptide hormone somatostatin [1, 2, 15]. It shows a high affinity for somatostatin-28 and is primarily expressed in the anterior pituitary gland, pancreatic islets, and the gastrointestinal tract [2, 7, 14]. In the pituitary, SSTR5 plays a pivotal role in regulating the secretion of growth hormone (GH), adrenocorticotropic hormone (ACTH), and prolactin, making it a key therapeutic target for endocrine disorders [3, 9, 17]. Activation of SSTR5 by synthetic agonists like pasireotide is used to treat acromegaly and Cushing's disease by suppressing hormone overproduction and inhibiting tumor cell proliferation [9, 12, 17]. However, SSTR5 activation also inhibits the secretion of insulin and glucagon-like peptide-1 (GLP-1), which can lead to hyperglycemia, a significant clinical side effect [10, 16, 17]. Conversely, SSTR5 antagonists are being investigated as potential treatments for type 2 diabetes to enhance insulin and incretin release [10, 11, 16]. The receptor's involvement in neuroendocrine tumors and its unique signaling pathways, including the inhibition of adenylyl cyclase and modulation of ion channels, continue to make it a focus of drug development and clinical research [1, 12, 17].

Other names

SST5SSTR5SS-5-RSS5-RSS5RSomatostatin receptor 5Somatostatin receptor subtype 5

Agonism leading to Gi-mediated inhibition of adenylyl cyclase, reduction of intracellular cAMP, activation of inward rectifier potassium channels, and inhibition of voltage-gated calcium channels [1, 2, 17].