Page 464 - Concise Pathology for Exam Preparation ( PDFDrive )

15 Diseases of the Hepatobiliary System and Pancreas 449

Cells Forming the Islets of Langerhans

• Alpha cells: Secrete glucagon (increases blood glucose)
• Beta cells: Secrete insulin (lowers blood glucose)
• Delta cells: Secrete somatostatin (inhibit the secretion of other islet hormones)
• Delta-1 cells: Secrete vasoactive intestinal polypeptide (VIP), which regulates and
stimulates the motility of intestines
• PP cells: Secrete pancreatic polypeptide (stimulate gastric secretion and inhibit intestinal
mobility)

Q. Write briefly on the clinicopathological features of acute pancreatitis.
Ans. Acute pancreatitis is defined as acute inflammation of the pancreas usually resulting
from injury to the exocrine pancreas.

Causes
• Metabolic: Hyperlipoproteinaemias, hypercalcaemia, alcoholism, drugs (eg, diuretics,
azathioprine and mercaptopurine)
• Genetic:
• Inherited mutations in genes encoding pancreatic enzymes or their inhibitors,
eg, SPINK1 (serine peptidase inhibitor Kazal type 1) which is an inhibitor of
trypsin.
• Hereditary pancreatitis with trypsinogen mutation is an autosomal dominant disease
caused by a mutation in PRSS1 gene that affects a site on trypsinogen molecule re-
quired for cleavage of trypsin, leading to continuous activation of other digestive
proenzymes and development of pancreatitis.
• Mechanical: Trauma (seat-belt injury), gallstones, injury during endoscopic procedures
like endoscopic retrograde cholangiopancreatography (ERCP) or perioperative injury
• Vascular: Shock, embolus and polyarteritis nodosa
• Infections: Mumps, coxsackie virus, mycoplasma pneumoniae, EBV and CMV
• Idiopathic pancreatitis: Occurs without any obvious cause and accounts for 10% of the
cases, and is the most common cause of pancreatitis (after alcohol and biliary disease)
The mechanisms underlying genesis of acute pancreatitis are summarized in
Flowchart 15.6.

Pancreatic duct Acinar cell Defective intracellular
obstruction injury transport

Interstitial oedema Release of intracellular Delivery of
proenzymes and proenzymes to
lysosomal hydrolases lysosomal compartment

Acinar cell injury

Inappropriate activation of pancreatic digestive enzymes inside the
ducts and acini of the exocrine pancreas

Release of digestive enzymes into the interstitial and
peripancreatic tissues and blood vessels

Autodigestion

Acute pancreatitis
FLOWCHART 15.6. The mechanisms underlying the genesis of acute pancreatitis.

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