The Small Intestine Becomes a Major Source of the Vasodilator Adrenomedullin During Sepsis | Research

The takeaway

The small intestine significantly increased adrenomedullin production during sepsis, contributing to the elevated circulating ADM levels that drive vasodilation and potential cardiovascular collapse.

Gut ADM surge
The small intestine dramatically increased ADM production during sepsis — the body's largest bacterial interface responding with massive vasodilator output

What the researchers found

Small intestinal ADM mRNA and protein were significantly upregulated during polymicrobial sepsis, with the gut releasing ADM into portal circulation, establishing the intestine as a major source of circulating ADM during sepsis.

Why it matters

The gut is the body's largest interface with bacteria. Its massive ADM production during sepsis could be a response to intestinal bacterial translocation — connecting gut barrier failure to systemic cardiovascular dysfunction.

How the study worked

Animal study in rat sepsis model. ADM mRNA (RT-PCR) and protein (immunohistochemistry, RIA) measured in small intestinal tissue. Portal vein ADM levels assessed for gut contribution to circulating ADM.

What this study cannot tell us

Rat sepsis model. The relative contribution of gut versus cardiovascular ADM to total circulating levels was not precisely quantified.

How to read the evidence

Moderate evidence from a controlled sepsis model with multi-level ADM measurement (mRNA, protein, portal vein levels).

When this study was published

Published in 2001. The gut's role in septic hemodynamics through peptide signaling has been further characterized.

The bigger picture

Sepsis involves gut-to-blood bacterial translocation. The gut's ADM response may initially protect intestinal blood flow but eventually overwhelms the cardiovascular system as sepsis progresses — another aspect of the gut's central role in sepsis.

Questions still open

Does gut ADM protect against intestinal barrier failure?
Could targeting gut ADM production prevent septic hemodynamic collapse?
Does gut ADM contribute to post-infectious hypotension?

Common questions

Why does the gut matter in sepsis?

During sepsis, the gut's barrier breaks down, allowing bacteria to enter the blood. This study shows the gut also floods the body with adrenomedullin — a vasodilator — which may initially protect intestinal blood flow but eventually contributes to dangerous blood pressure drops.

Could gut protection prevent septic shock?

Possibly. If the gut's ADM production drives cardiovascular collapse in sepsis, protecting intestinal barrier function or modulating gut ADM release could prevent the transition from compensated to decompensated shock.

Read the original research

The small intestine is an important source of adrenomedullin release during polymicrobial sepsis.

American journal of physiology. Regulatory, integrative and comparative physiology, 281(2), R654-60

View on PubMed ↗

Citation

Zhou, M; Chaudry, I H; Wang, P. (2001). The small intestine is an important source of adrenomedullin release during polymicrobial sepsis.. American journal of physiology. Regulatory, integrative and comparative physiology, 281(2), R654-60.