新しい胃腸内分泌細胞タイプからのガストリンのCOOH-端末テトラペプチドアミドに似たペプチド

Stem cells are undifferentiated cells that divide and produce more stem cells or progenitor cells that differentiate into mature, specialized cell types. All the cells in the body are generated from stem cells in the early embryo, but small populations of stem cells are also present in many adult tissues including the bone marrow, brain, skin, and gut. These adult stem cells typically produce the various cell types found in that tissue—to replace cells that are damaged or to continuously renew...

The human body carefully regulates the internal pH of different organs to maintain homeostasis. For example, while the blood plasma maintains a neutral pH of 7, the stomach lumen has an acidic pH of 1.5 - 3.5. The low pH of stomach lumen helps kill pathogens in the food and break down complex food molecules.
The acid-secreting gastric mucosal epithelial cells (parietal cells) lining the stomach lumen maintain the low pH in the lumen. Numerous ion transporters and channels on these parietal...

The intestinal epithelial lining rapidly renews every 4 to 5 days. The renewal is facilitated by intestinal stem cells (ISCs) located at the base of the crypt– a gland located at the bottom of each villus. ISCs divide asymmetrically to form new stem cells and progenitor daughter cells. The daughter cells are called transit-amplifying (TA) cells which move upwards along the crypt and either differentiate into absorptive cells– the enterocytes or secretory cells– including the goblet,...

The pancreas, a vital organ within the abdominal cavity, plays dual roles in the digestive and endocrine systems, collaborating with exocrine and endocrine cells to maintain optimal digestion and blood sugar levels.
Exocrine function is carried out by acinar cells, organized into clusters known as acini. These cells contribute to digestion by releasing substantial quantities of enzyme-rich, alkaline digestive juices.
Concurrently, the dispersed clusters of endocrine cells throughout the...

Digestive activity regulation hinges on three primary components. Activation is prompted by a multitude of mechanical and chemical indicators, primarily detected by receptors within the stomach and intestines' walls. These receptors predominantly respond to factors such as mechanical stretching of the organ walls, changes in pH and osmolarity, and the presence of digesting materials and their by-products.
The effectors in this regulation system are glands and smooth muscles. Activation of these...

Enteroendocrine cells, accounting for only 1% of stomach epithelial cells, play a significant role in digestion and are classified by their digestive hormone secretions.
Each of these hormones secreted by different enteroendocrine cells plays a unique role in digestion. Here are a few examples: