Related Experiment Video
Updated: May 21, 2026

Mixed Primary Cultures of Murine Small Intestine Intended for the Study of Gut Hormone Secretion and Live Cell Imaging of Enteroendocrine Cells
Published on: April 20, 2017
Calcium-sensing receptor mediates dietary peptide-induced CCK secretion in enteroendocrine STC-1 cells
Shingo Nakajima1, Tohru Hira, Hiroshi Hara
1Graduate School of Agriculture, Hokkaido University, Kita-ku, Sapporo, Japan.
Scope:
Dietary peptides are potent stimulators of cholecystokinin (CCK) secretion, but the sensing mechanism in CCK-producing cells is poorly understood. Recently, it has been demonstrated that the calcium-sensing receptor (CaSR) mediates CCK secretion induced by amino acids. We investigated the role of CaSR in CCK secretions induced by various protein hydrolysates (egg albumin, meat, casein, azuki bean, soybean ß-conglycinin, and potato) in the enteroendocrine cell line STC-1.
Methods And Results:
CCK secretions in response to these hydrolysates were measured in the STC-1 cells with or without CaSR antagonist (NPS 2143) treatment. Changes in intracellular calcium concentration ([Ca²⁺](i) ) in response to protein hydrolysates were measured in Human embryonic kidney (HEK) 293 cells transfected with CaSR-expression vector. Protein hydrolysates-induced CCK secretions were decreased by CaSR antagonist treatment, except meat hydrolysate-induced secretion. Protein hydrolysates increased [Ca²⁺](i) in CaSR-transfected HEK 293 cells. CaSR antagonist treatment suppressed low molecular weight fractions of azuki hydrolysate-induced CCK secretion, but the secretion induced by both low and high molecular weight fractions of ß-conglycinin hydrolysate. Further, CCK secretion induced by peptide fractions (> 500 Da) derived from various protein hydrolysates were also reduced by CaSR antagonist.
Conclusion:
These results demonstrate that CaSR plays a significant role in sensing various dietary peptides in triggering CCK secretion in enteroendocrine cells.
Related Concept Videos
Feedback Regulation of Calcium Concentration
Various transmembrane receptors, such as G protein-coupled receptors (GPCRs), elicit a response to extracellular signals by increasing cytosolic calcium. Activated GPCRs...
Hormones Secreted by the Stomach
Each of these hormones secreted by different enteroendocrine cells plays a unique role in digestion. Here are a few examples:
Calmodulin-dependent Signaling
The Ca2+-CaM complex does not have enzymatic activity by itself. Instead, the complex binds downstream target proteins, including membrane proteins or enzymes,...
Cell Specific Gene Expression
Synthesis and Functions of Calcitonin
The exact mechanisms by which calcitonin operates in calcium homeostasis remain elusive, but its significance is evident in several vital...
Hormonal Regulation

