Blocking the Enzyme That Destroys Natural Painkillers Enhances the Body's Own Pain Relief

Inhibiting endopeptidase 24.15 (which degrades longer opioid peptides like dynorphin) enhanced natural stress-induced pain relief — a strategy to boost endogenous painkillers without adding external opioids.

Kest, B et al.·Physiology & behavior·1991·Preliminary EvidenceAnimal StudyAnimal Study
RPEP-00197Animal StudyPreliminary Evidence1991RETHINKTHC RESEARCH DATABASErethinkthc.com/research

Quick Facts

Study Type
Animal Study
Evidence
Preliminary Evidence
Sample
Not reported

What This Study Found

Central administration of an endopeptidase 24.15 inhibitor enhanced opioid-mediated swim stress antinociception. The effect was reversed by naloxone.

Key Numbers

How They Did This

Rats received intracerebroventricular injections of the enzyme inhibitor cFP-AAF-pAB before swim stress testing. Pain thresholds were measured before and after. Naloxone was used to confirm opioid involvement.

Why This Research Matters

Instead of adding external opioids (which carry addiction risk), this approach boosts the body's own pain-relief peptides by preventing their breakdown. This could inspire new pain treatments.

The Bigger Picture

This represents a fundamentally different approach to pain management: instead of adding opioid drugs (with their addiction and side effect risks), boost the body's own opioid peptides by preventing their breakdown. This concept has inspired development of dual enkephalinase inhibitors now in clinical trials.

What This Study Doesn't Tell Us

Animal study in rats using brain injections. The enzyme inhibitor was given centrally, not orally. Acute stress model may not represent chronic pain. Early-stage research.

Questions This Raises

  • ?Could oral endopeptidase inhibitors provide practical pain relief?
  • ?Would this approach have lower addiction risk than external opioids?

Trust & Context

Key Stat:
Enhanced endogenous pain relief Endopeptidase 24.15 inhibitor boosted the body's own opioid-mediated pain relief during stress, reversed by naloxone
Evidence Grade:
Preliminary animal study with brain injection. Proof of concept for enzyme inhibition strategy but far from clinical application.
Study Age:
Published in 1991. This concept has evolved into dual enkephalinase inhibitors now in clinical development.
Original Title:
Increases in opioid-mediated swim antinociception following endopeptidase 24.15 inhibition.
Published In:
Physiology & behavior, 50(4), 843-5 (1991)
Database ID:
RPEP-00197

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

How is this different from taking a painkiller?

Instead of adding an external opioid drug, this approach protects the body's own natural painkillers from being destroyed. It's like increasing your natural pain relief capacity rather than replacing it with a drug.

Could this be less addictive than opioid drugs?

Theoretically yes. By working through the body's own opioid system rather than flooding receptors with external drugs, the response may be more balanced and physiological — though this needs clinical validation.

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Cite This Study

RPEP-00197·https://rethinkpeptides.com/research/RPEP-00197

APA

Kest, B; Orlowski, M; Bodnar, R J. (1991). Increases in opioid-mediated swim antinociception following endopeptidase 24.15 inhibition.. Physiology & behavior, 50(4), 843-5.

MLA

Kest, B, et al. "Increases in opioid-mediated swim antinociception following endopeptidase 24.15 inhibition.." Physiology & behavior, 1991.

RethinkPeptides

RethinkPeptides Research Database. "Increases in opioid-mediated swim antinociception following ..." RPEP-00197. Retrieved from https://rethinkpeptides.com/research/kest-1991-increases-in-opioidmediated-swim

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.