Opioid Peptides Also Suppressed Thyroid Hormone Release From the Stomach

Beta-endorphin, leu-enkephalin, and dynorphin all inhibited TRH release from rat stomach tissue in a dose-dependent, naloxone-reversible manner — matching the cecum findings.

Mitsuma, T et al.·Endocrinologia experimentalis·1989·Preliminary Evidencein-vitro
RPEP-00126In VitroPreliminary Evidence1989RETHINKTHC RESEARCH DATABASErethinkthc.com/research

Quick Facts

Study Type
in-vitro
Evidence
Preliminary Evidence
Sample
Not reported

What This Study Found

Three opioid peptides from different families all inhibited TRH release from rat stomach in a dose-dependent manner, reversible by naloxone.

Key Numbers

How They Did This

Rat stomach tissue was incubated with opioid peptides and naloxone. TRH released into the medium was measured by radioimmunoassay.

Why This Research Matters

This confirms that opioid regulation of gut TRH is not limited to one part of the digestive tract. The stomach also responds to opioid peptides by reducing hormone release.

The Bigger Picture

The opioid-TRH regulatory system extends throughout the gut, suggesting a widespread gut opioid-thyroid network that may be clinically important.

What This Study Doesn't Tell Us

In-vitro study using isolated stomach tissue. Whether this regulation matters in living animals and what functional consequences it has remain unknown.

Questions This Raises

  • ?Is the opioid-TRH system altered in GI diseases?
  • ?Could this pathway contribute to the metabolic effects of opioid drugs?

Trust & Context

Key Stat:
GI tract-wide effect Opioid-TRH suppression confirmed in both stomach and cecum
Evidence Grade:
Preliminary in-vitro study confirming cecum findings in a second gut segment.
Study Age:
Published in 1989 — extended the gut opioid-thyroid finding to the stomach.
Original Title:
Effect of endogenous opioid peptides on TRH release from rat stomach in vitro.
Published In:
Endocrinologia experimentalis, 23(1), 11-6 (1989)
Database ID:
RPEP-00126

Evidence Hierarchy

Meta-Analysis / Systematic Review
Randomized Controlled Trial
Cohort / Case-Control
Cross-Sectional / ObservationalSnapshot without intervening
This study
Case Report / Animal Study
What do these levels mean? →

Frequently Asked Questions

Why test multiple gut segments?

Confirming the effect in both stomach and cecum shows the opioid-TRH connection is a general gut phenomenon, not limited to one region.

What does TRH do in the stomach?

TRH in the stomach may regulate acid secretion, motility, and blood flow. Its suppression by opioid peptides could affect digestive function.

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Cite This Study

RPEP-00126·https://rethinkpeptides.com/research/RPEP-00126

APA

Mitsuma, T; Hirooka, Y; Nakada, K; Nomura, A; Nogimori, T. (1989). Effect of endogenous opioid peptides on TRH release from rat stomach in vitro.. Endocrinologia experimentalis, 23(1), 11-6.

MLA

Mitsuma, T, et al. "Effect of endogenous opioid peptides on TRH release from rat stomach in vitro.." Endocrinologia experimentalis, 1989.

RethinkPeptides

RethinkPeptides Research Database. "Effect of endogenous opioid peptides on TRH release from rat..." RPEP-00126. Retrieved from https://rethinkpeptides.com/research/mitsuma-1989-effect-of-endogenous-opioid

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.