What Is Cholecystokinin?
5-800ng / L.
- Cholecystokinin (CCK) is a type I secretory cell in the small intestinal mucosa and is also found in the brain and peripheral nerves. It is the most powerful neurotransmitter in the central and peripheral nervous system. CCK is the most abundant peptide in the brain. . CCK functions as both endocrine hormone and neurotransmitter, and is one of the recognized "brain-gut peptides". CCK exists in a variety of molecular forms, including CCK33, which contains 33 amino acids, as well as CCK39, CCK58 and so on. Among them, CCK58 has the entire biological activity of the entire cholecystokinin molecule, and the activity is 2-10 times stronger than that of CCK33. Type cells mainly exist in the duodenum and upper jejunum. Excited vagus nerves, hydrochloric acid, proteins and decomposition products, fats and hydrolysates, and Ca2 + ions are factors that stimulate CCK secretion. CCK stimulates pancreatic enzymes secreted by the pancreas. Feedback inhibits CCK release. CCK has a wide range of biological activities, mainly acting as hormones and neurotransmitters. The effects of its hormonal effects on the secretory function of the digestive system are as follows: Stimulate pancreatic enzymes and bicarbonate secretion, enhance pancreatic enzyme activity, and stimulate islets to release insulin. CCK has a co-receptor on parietal cells that competes with gastrin, and can inhibit the gastric acid secretion response caused by gastrin. Stimulate the duodenal secretion, and it can also stimulate liver and bile secretion. The effects on the motor function of the digestive system are: CCK has a strong contraction of the gallbladder. It also has an excitatory effect on the gastrointestinal smooth muscle, causing contraction of the stomach and pyloric sphincter in the resting state, and inhibiting the contraction of the esophageal sphincter and Oddi's sphincter.
- Name
- Cholecystokinin
- category
- blood
Cholecystokinin normal value
- 5-800ng / L.
Clinical significance of cholecystokinin
- (1) Gastrinoma: Patients' serum CCK levels also increased significantly. The increase in gastrin levels caused endogenous gastric acid in the small intestine to stimulate type I secretory cells, which increased CCK levels. (2) Small bowel disease: The lesion is in the upper small intestine, the type I secretion cells are damaged, and the CCK content in the blood decreases. If the lesion is in the distal small intestine, the CCK level does not change. (3) Cholecystokinin diarrhea syndrome: caused by a large amount of CCK secretion, resulting in colon dysfunction, with abdominal pain and chronic diarrhea, and increased gastric acid secretion, serum CCK can be 3-4 times higher than normal, and gastrin levels are normal Or low. (4) In patients with insufficient pancreatic function, such as chronic pancreatitis, the concentration of cholecystokinin in circulating blood is significantly increased. In normal pancreatic exocrine pancreatic enzymes have a negative feedback effect on cholecystokinin, and insufficient pancreatic secretory function has a reduced inhibitory effect on CCK release. Therefore, the fasting plasma CCK level can indirectly reflect the exocrine function of the pancreas. When the exocrine function of the pancreas decreases, the CCK content in the blood increases significantly.
Cholecystokinin precautions
- Fasting serum should be collected and submitted for immediate inspection.