Non-endocrine gland endocrinology Flashcards
What are the incretins?
Gastric-inhibitory peptide (GIP)
Glucagon like peptide (GLP-1)
Where is gastrin produced from?
G cells in duodenum and stomach
What is the stimuli that causes gastrin secretion?
Presence of peptides and AAs in gastric lumen
Stomach distension
Vagal stimulation
Hypercalcaemia
What are the major effects of gastrin?
Stimulates release of gastric acid from parietal call - decreased pH
Stimulates release of pepsinogen from chief cells
Why is gastric secretion inhibited at ~pH3
Further decrease in pH can cause gastric ulceration
What is the clinical relevance of gastrin in cats and dogs
Gastrinomas - tumours in gastric secreting cells
Leads to excessive gastrin production => vomiting, inappetance, abdominal pain
Where is secretin produced?
duodenum
What stimuli causes secretin secretion?
H+ in SI/acid from stomach
What is the major effect of secretin?
Stimulates release of bicarbonate-rich pancreatic and biliary fluid to buffer gastric acid
Where is cholecystokinin (CKK) produced?
duodenum
Brain cells
What is the stimuli for CCK (cholecystokinin) release?
fatty acids, monoglycerides and AAs in SI
Expansion of stomach after meal => CCK in brain
Where is gastric inhibitory polypeptide (GIP) produced?
Proximal SI
What is the stimuli that causes the secretion of GIP (gastric inhibitory polypeptide)?
Fat, glucose and AAs in SI
What are the major effects of GIP (gastric inhibitory polypeptide)?
Inhibits gastric secretion and motility
Increases release of insulin in response to elevated blood glucose levels
Increases insulin sensitivity of adipocytes
Stimulation of lipoprotein lipase activity in adipocytes
Where is GLP-1 (glucagon like peptide) produced?
L-cells of ileum and jejunum