Versatile Functions of Somatostatin and Somatostatin Receptors in the Gastrointestinal System.

Bilal Haider Shamsi,Xun Xu,Xiao Kang Xu,Xue Qun Chen,Mahanand Chatoo

doi:10.3389/fendo.2021.652363

Abstract

Somatostatin (SST) and somatostatin receptors (SSTRs) play an important role in the brain and gastrointestinal (GI) system. SST is produced in various organs and cells, and the inhibitory function of somatostatin-containing cells is involved in a range of physiological functions and pathological modifications. The GI system is the largest endocrine organ for digestion and absorption, SST-endocrine cells and neurons in the GI system are a critical effecter to maintain homeostasis via SSTRs 1-5 and co-receptors, while SST-SSTRs are involved in chemo-sensory, mucus, and hormone secretion, motility, inflammation response, itch, and pain via the autocrine, paracrine, endocrine, and exoendocrine pathways. It is also a power inhibitor for tumor cell proliferation, severe inflammation, and post-operation complications, and is a first-line anti-cancer drug in clinical practice. This mini review focuses on the current function of producing SST endocrine cells and local neurons SST-SSTRs in the GI system, discusses new development prognostic markers, phosphate-specific antibodies, and molecular imaging emerging in diagnostics and therapy, and summarizes the mechanism of the SST family in basic research and clinical practice. Understanding of endocrines and neuroendocrines in SST-SSTRs in GI will provide an insight into advanced medicine in basic and clinical research.

Highlights

Somatostatin (SST-14,28) is considered a universal endocrine molecule and a peptide hormone in the central nervous system (CNS), peripheral nervous system (PNS), and enteric nervous system (ENS) [1,2,3,4,5]
SST in the GI system is involved in the inhibition of secretory activity and intestinal motility, blood flow, inflammation response, conduction of pain and sensation, and modulation of the release of hormone factors and other neurotransmitters, while SST-SSTRs mediate the release of gastric juice, intestinal juice, gastric acid, and other hormones via other endocrine factors [7,8,9]
The study demonstrated the mechanisms of tight glycemic control in islet-D-cells, mice urocortin-3 co-released with insulin, and increased glucosestimulated SST secretion via cognate receptors, this indicated SST-dependent negative feedback control of insulin secretion [67]

Summary

Introduction

Somatostatin (SST-14,28) is considered a universal endocrine molecule and a peptide hormone in the central nervous system (CNS), peripheral nervous system (PNS), and enteric nervous system (ENS) [1,2,3,4,5]. There are various SST-endocrine-cells embedded in the GI tract, which release gastrointestinal hormones to regulate GI function, such as SST producing-D cells from the stomach, intestine, and pancreas. SST in the GI system is involved in the inhibition of secretory activity and intestinal motility, blood flow, inflammation response, conduction of pain and sensation, and modulation of the release of hormone factors and other neurotransmitters, while SST-SSTRs mediate the release of gastric juice, intestinal juice, gastric acid, and other hormones via other endocrine factors [7,8,9].

Results

Conclusion