Gastrin-34

Where it comes from

Made in

G cells of the duodenum above all

Sent out by

Protein meals; lingers longer in blood than gastrin-17

Acts on

• Enterochromaffin-like cells
• Parietal cells

What it does

• Drives acid as gastrin-17 does, more slowly
• Dominates fasting gastrin levels because it is cleared about five times more slowly ¹
• Weaker than gastrin-17 dose for dose, so a given blood level means less acid than the same level of the short form

In medicine

• Counted in “total gastrin” assays, including the gastrinoma work-up ²
• Which forms an assay sees decides what a gastrin result means, and antibodies differ widely; a normal result on one kit can be high on another ²

Beyond the body’s own use

• Not studied apart from gastrin-17, and no analogue of this length has been taken into a trial
• Its practical interest is diagnostic. Because it sets the fasting level, a laboratory that measures the forms separately reads a mildly raised gastrin differently from one that does not, which matters when the question is gastrinoma ²