How Anesthesia Triggers Stress Hormones and Opioid Release in Horses
Thiopentone/halothane anesthesia in ponies triggered release of endogenous opioids, ACTH, cortisol, and stress hormones, with higher halothane causing more cardiovascular depression.
Quick Facts
What This Study Found
Anesthesia triggered release of endogenous opioids, ACTH, vasopressin, cortisol, and catecholamines, with constant higher halothane producing more cardiovascular depression.
Key Numbers
How They Did This
Eleven ponies received thiopentone/halothane anesthesia. Six were maintained at constant 1.2% halothane, five at variable 0.8-1.2%. Blood hormones and cardiorespiratory parameters were monitored.
Why This Research Matters
Understanding how anesthesia triggers opioid and stress hormone release helps veterinarians manage surgical pain and cardiovascular risks in horses, and has parallels to human anesthesiology.
The Bigger Picture
Surgery triggers a massive stress response. Understanding how anesthesia itself activates endogenous opioid and stress hormone release helps anesthesiologists manage pain and cardiovascular stability during surgery, in both veterinary and human medicine.
What This Study Doesn't Tell Us
Small veterinary study with 11 ponies. Two treatment groups with different protocols. Results may not directly apply to other species or anesthetic combinations.
Questions This Raises
- ?Does the endogenous opioid release during anesthesia provide meaningful pain relief, or is it purely a stress marker?
- ?How do modern anesthetic protocols compare in their stress hormone triggering effects?
Trust & Context
- Key Stat:
- 11 ponies studied Comparison of two halothane protocols showed higher constant doses produced more cardiovascular depression
- Evidence Grade:
- Preliminary — small veterinary study with only 11 animals split across two treatment groups.
- Study Age:
- Published in 1995. Thiopentone/halothane protocols have largely been replaced by newer agents, but the physiological principle of anesthesia-triggered stress hormone release remains relevant.
- Original Title:
- Pituitary-adrenal activity and opioid release in ponies during thiopentone/halothane anaesthesia.
- Published In:
- Research in veterinary science, 58(1), 35-41 (1995)
- Authors:
- Luna, S P, Taylor, P M
- Database ID:
- RPEP-00328
Evidence Hierarchy
Tests effects in animals (usually mice or rats), not humans.
What do these levels mean? →Frequently Asked Questions
Does anesthesia trigger the body's own pain-relieving chemicals?
Yes. This study showed anesthesia triggers release of beta-endorphin and other endogenous opioids as part of the stress response, alongside cortisol and adrenaline.
Is this relevant to human anesthesia?
The stress hormone response to anesthesia is similar across mammals. Human anesthesiologists also manage anesthesia-induced hormonal changes, though specific drug protocols differ.
Read More on RethinkPeptides
Cite This Study
https://rethinkpeptides.com/research/RPEP-00328APA
Luna, S P; Taylor, P M. (1995). Pituitary-adrenal activity and opioid release in ponies during thiopentone/halothane anaesthesia.. Research in veterinary science, 58(1), 35-41.
MLA
Luna, S P, et al. "Pituitary-adrenal activity and opioid release in ponies during thiopentone/halothane anaesthesia.." Research in veterinary science, 1995.
RethinkPeptides
RethinkPeptides Research Database. "Pituitary-adrenal activity and opioid release in ponies duri..." RPEP-00328. Retrieved from https://rethinkpeptides.com/research/luna-1995-pituitaryadrenal-activity-and-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.