Cholecystokinin

Cholecystokinin (CCK) is a type I secretory cell in the intestinal mucosa. It is also present 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 is functionally a combination of endocrine hormones and neurotransmitters and is recognized as one of the "brain-gut peptides". CCK exists in various molecular forms, including CCK33 containing 33 amino acids, and CCK39, CCK58 and the like. Among them, CCK58 has the entire biological activity of the entire cholecystokinin molecule, and its activity is 2-10 times stronger than that of CCK33. Type I cells are mainly found in the duodenum and upper jejunum. The vagus nerve excitability, hydrochloric acid, protein and decomposition products, fat and hydrolysate, Ca2+ ion are the factors that stimulate CCK secretion, while CCK stimulates pancreatic secretion of pancreatic enzyme. Feedback suppresses the release of CCK. CCK has a wide range of biological activities, mainly acting as hormones and neurotransmitters. Basic Information Specialist classification: Digestive examination classification: blood examination Applicable gender: whether men and women apply fasting: fasting Tips: Collect fasting serum and submit it immediately. Normal value 5 to 800 ng/L. Clinical significance (1) The serum CCK level of patients with gastrinoma is also significantly increased. It is due to the elevated gastrin level, which causes endogenous gastric acid in the small intestine to stimulate type I secretory cells, which increases the level of CCK. (2) Intestinal disease lesions in the upper part of the small intestine, type I secretory cells are damaged, blood CCK content is decreased, such as lesions in the distal small intestine, CCK levels are unchanged. (3) cholecystokinin diarrhea syndrome caused by a large number of CCK secretion, leading to colonic dysfunction, accompanied by abdominal pain and chronic diarrhea, and increased gastric acid secretion, serum CCK can be 3 to 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. Pancreatic enzyme in normal pancreatic exocrine has a negative feedback effect on cholecystokinin, and the inhibition of CCK release is reduced by pancreatic secretion function. Therefore, fasting plasma CCK levels can indirectly reflect the exocrine function of the pancreas. When the pancreatic exocrine function declines, the CCK content in the blood increases significantly. High results may be diseases: cystic duct syndrome, precautions for cholelithiasis in the elderly Collection of fasting serum should be sent immediately. Inspection process Digestive tract hormone determination. Not suitable for the crowd Hemophilia and diffuse intravascular coagulation. Adverse reactions and risks Discomfort: There may be pain, swelling, tenderness, and visible subcutaneous ecchymosis at the puncture site.