CASE FILES: BIOCHEMISTRY
A N SW E R S TO C A SE 31: G A L L ST O N E S
A 45-year-old female presents with hypercholesterolinemia, ultra-
sound evidence of gallstones, and recurrent symptoms of gallbladder disease.
Surgical candidates: Frequent and severe attacks, previous
complications from gallstones, presence of underlying condition
predisposing the patient to increased risk of gallbladder disease.
Components of gallstones: Cholesterol, calcium bilirubinate, and bile
Abdominal x-rays and diagnosis: Mixed stones much easier to see
on plain film secondary to calcifications, comprising approximately
10 percent of gallstones.
C L IN IC A L C O R R E L A T IO N
This individual fits the “classic” patient with gallbladder disease: female,
middle-aged, overweight. The gallbladder acts to store bile salts produced by
the liver. The gallbladder is stimulated to contract when food enters the small
intestine; the bile salts then travel through the bile duct to the ampulla of Vater
into the duodenum. The bile salts act to emulsify fats, helping with the diges-
tion of fat. Gallstones form when the solutes in the gallbladder precipitate. The
two main types of stones are cholesterol stones and pigmented stones.
Cholesterol stones are usually yellow-green in appearance and account for
approximately 80 percent of gallstones. Pigmented stones are usually made of
bilirubin and appear dark in color. Patients may have pain from the gallstones,
usually after a fatty meal. The pain is typically epigastric or right upper quad-
rant and perhaps radiating to the right shoulder. If the gallbladder becomes
inflamed or infected, cholecystitis can result. The stones can also travel
through the bile duct and obstruct biliary flow leading to jaundice (yellow
color or the skin), or irritate the pancreas and cause pancreatitis.
A PPR O A C H TO B IL E SALT M E T A B O L ISM
Know about bile salt metabolism.
Be able to identify where bile salts are synthesized.
Know where bile salts emulsify dietary fats.