The Body's Own Opioids Make Hemorrhagic Shock Worse — Blocking Them Improves Survival

Blocking opioid peptides with naloxone or specific antibodies improved hemorrhage tolerance in rats — the body's own opioid response paradoxically worsens blood loss shock.

van den Berg, M H et al.·Circulatory shock·1991·Preliminary EvidenceAnimal StudyAnimal Study
RPEP-00216Animal StudyPreliminary Evidence1991RETHINKTHC RESEARCH DATABASErethinkthc.com/research

Quick Facts

Study Type
Animal Study
Evidence
Preliminary Evidence
Sample
Not reported

What This Study Found

Central and peripheral naloxone increased bleeding volumes before pressure dropped. Brain antibodies against beta-endorphin, alpha-endorphin, and dynorphin A also improved hemorrhage tolerance.

Key Numbers

How They Did This

Anesthetized rats underwent controlled stepwise hemorrhage. Naloxone, peripheral naloxone methobromide, or opioid peptide antibodies were administered centrally. Bleeding volumes at each pressure step were measured.

Why This Research Matters

This reveals that the body's opioid peptides actually make hemorrhagic shock worse. Blocking them could improve survival during severe blood loss, a finding relevant to trauma and emergency medicine.

The Bigger Picture

This finding has clinical implications for trauma and emergency medicine. If opioid blockers improve hemorrhage tolerance, naloxone could potentially be used as a trauma resuscitation drug.

What This Study Doesn't Tell Us

Animal study in anesthetized rats. Anesthesia and controlled hemorrhage differ from real trauma. Antibody specificity may not be perfect. Clinical translation is not straightforward.

Questions This Raises

  • ?Should naloxone be administered during traumatic hemorrhage?
  • ?Which opioid peptide is most responsible for worsening shock?

Trust & Context

Key Stat:
Opioid blockade improved hemorrhage tolerance Both central and peripheral naloxone increased the bleeding volume tolerated before dangerous blood pressure drops
Evidence Grade:
Preliminary animal study in anesthetized rats. Controlled hemorrhage model is artificial but allows precise measurements.
Study Age:
Published in 1991. Naloxone for hemorrhagic shock has been studied clinically with mixed but promising results.
Original Title:
Endogenous opioid peptides and blood pressure regulation during controlled, stepwise hemorrhagic hypotension.
Published In:
Circulatory shock, 35(2), 102-8 (1991)
Database ID:
RPEP-00216

Evidence Hierarchy

Meta-Analysis / Systematic Review
Randomized Controlled Trial
Cohort / Case-Control
Cross-Sectional / Observational
Case Report / Animal StudyOne case or non-human subjects
This study

Tests effects in animals (usually mice or rats), not humans.

What do these levels mean? →

Frequently Asked Questions

Why do opioids make hemorrhage worse?

During blood loss, opioid peptides may cause excessive vasodilation (blood vessel relaxation), reduce the heart's compensatory response, and blunt the sympathetic fight-or-flight response — all of which are needed to survive hemorrhage.

Could naloxone save lives in trauma?

This animal study suggests it could help. Some clinical trials have shown benefits, but the evidence is mixed. Naloxone for hemorrhagic shock remains an active area of research.

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Cite This Study

RPEP-00216·https://rethinkpeptides.com/research/RPEP-00216

APA

van den Berg, M H; van Giersbergen, P L; Cox-van Put, J; de Jong, W. (1991). Endogenous opioid peptides and blood pressure regulation during controlled, stepwise hemorrhagic hypotension.. Circulatory shock, 35(2), 102-8.

MLA

van den Berg, M H, et al. "Endogenous opioid peptides and blood pressure regulation during controlled, stepwise hemorrhagic hypotension.." Circulatory shock, 1991.

RethinkPeptides

RethinkPeptides Research Database. "Endogenous opioid peptides and blood pressure regulation dur..." RPEP-00216. Retrieved from https://rethinkpeptides.com/research/van-1991-endogenous-opioid-peptides-and

Access the Original Study

Study data sourced from PubMed, a service of the U.S. National Library of Medicine, National Institutes of Health.

This study breakdown was produced by the RethinkPeptides research team. We analyze and report published research findings without making health recommendations. All interpretations are based solely on the published abstract and study data.