Which test directly determines the exocrine secretory capacity of the pancreas?

Which test directly determines the exocrine secretory capacity of the pancreas?

• A. Secretin/CCK test
• B. Amylase
• C. Quantitative fecal fat analysis
• D. d-Xylose test

Answer: (A)

Exocrine pancreatic function is best assessed by a test that provokes the pancreas to secrete its juice and then measures that secretion itself. The secretin/CCK test does exactly this: secretin stimulates the ductal cells to release bicarbonate-rich fluid, while cholecystokinin stimulates the acinar cells to release enzyme-rich juice. By measuring the amount and composition of pancreatic juice in response to these hormones, you get a direct readout of the pancreas’s exocrine secretory capacity. Other options don’t measure actual secretions. Amylase in the blood tells you about enzyme leakage or injury but not the pancreas’s total secretory output. Quantitative fecal fat analysis assesses fat digestion efficiency, which can be influenced by many factors beyond pancreatic secretion. The d-xylose test evaluates intestinal absorption, not the pancreas’s secretory function.

Exocrine pancreatic function is best assessed by a test that provokes the pancreas to secrete its juice and then measures that secretion itself. The secretin/CCK test does exactly this: secretin stimulates the ductal cells to release bicarbonate-rich fluid, while cholecystokinin stimulates the acinar cells to release enzyme-rich juice. By measuring the amount and composition of pancreatic juice in response to these hormones, you get a direct readout of the pancreas’s exocrine secretory capacity.

Other options don’t measure actual secretions. Amylase in the blood tells you about enzyme leakage or injury but not the pancreas’s total secretory output. Quantitative fecal fat analysis assesses fat digestion efficiency, which can be influenced by many factors beyond pancreatic secretion. The d-xylose test evaluates intestinal absorption, not the pancreas’s secretory function.