Endocannabinoid Enzymes Play Different Roles in Body Temperature Regulation
In mice, blocking the enzyme that breaks down 2-AG worsened hypothermia from both cold exposure and bacterial toxin through CB1 receptors, while blocking the enzyme that breaks down anandamide had no effect on temperature.
Quick Facts
What This Study Found
Researchers tested how two endocannabinoid-degrading enzymes, MAGL (which breaks down 2-AG) and FAAH (which breaks down anandamide), contribute to body temperature regulation under stress.
Inhibiting MAGL with JZL184 made hypothermia worse in mice challenged with either a bacterial endotoxin (LPS) or cold (4 degrees Celsius) environment. These effects were blocked by a CB1 antagonist but not a CB2 antagonist, confirming a CB1-mediated mechanism.
In contrast, inhibiting FAAH with PF-3845, which raises anandamide levels, had no effect on either type of hypothermia. Neither MAGL nor FAAH inhibition affected normal body temperature, showing these enzymes specifically matter during temperature challenges.
Key Numbers
LPS caused hypothermia lasting 12+ hours; cold (4 degrees Celsius) caused mild hypothermia resolving within 30 minutes; JZL184 worsened both; PF-3845 had no effect on either; effects blocked by rimonabant (CB1) but not SR144528 (CB2)
How They Did This
Mouse study using MAGL inhibitor (JZL184) and FAAH inhibitor (PF-3845) followed by either LPS injection (2 mg/kg) or cold environment (4 degrees Celsius) challenge. Core body temperature measured over 12 hours. CB1 and CB2 antagonists used to identify receptor mechanisms.
Why This Research Matters
This study reveals that the two main endocannabinoid pathways (2-AG and anandamide) play fundamentally different roles in temperature regulation. Since THC activates the same receptors as 2-AG, this helps explain why cannabis use can affect body temperature.
The Bigger Picture
The differential roles of 2-AG and anandamide in thermoregulation add to growing evidence that these two endocannabinoids are not interchangeable. This has implications for drug development targeting specific endocannabinoid pathways.
What This Study Doesn't Tell Us
Mouse study with potential species differences. Used pharmacological inhibitors rather than genetic knockouts for the primary experiments. Acute challenges may not reflect chronic conditions.
Questions This Raises
- ?Does chronic cannabis use alter thermoregulatory responses through 2-AG pathway disruption?
- ?Could MAGL inhibitors worsen fever or hypothermia in clinical settings?
- ?Do these findings explain the hot-bath relief pattern in cannabinoid hyperemesis syndrome?
Trust & Context
- Key Stat:
- 2-AG pathway involved in temperature regulation; anandamide pathway was not
- Evidence Grade:
- Well-controlled animal study with clear receptor specificity demonstrated, but limited to mouse models.
- Study Age:
- Published in 2015. Endocannabinoid enzyme pharmacology has continued to develop.
- Original Title:
- Endocannabinoid Catabolic Enzymes Play Differential Roles in Thermal Homeostasis in Response to Environmental or Immune Challenge.
- Published In:
- Journal of neuroimmune pharmacology : the official journal of the Society on NeuroImmune Pharmacology, 10(2), 364-70 (2015)
- Authors:
- Nass, Sara R(3), Long, Jonathan Z(7), Schlosburg, Joel E(7), Cravatt, Benjamin F, Lichtman, Aron H, Kinsey, Steven G
- Database ID:
- RTHC-01025
Evidence Hierarchy
Tests effects in animals (usually mice or rats), not humans.
What do these levels mean? →Frequently Asked Questions
Why does cannabis sometimes make people feel cold?
THC activates CB1 receptors similarly to the endocannabinoid 2-AG. This study showed that elevated 2-AG (through MAGL inhibition) worsened hypothermia via CB1 receptors, suggesting THC could have similar temperature-lowering effects.
What is the difference between 2-AG and anandamide?
Both are endocannabinoids, but this study showed they have different functions in temperature regulation. Only the 2-AG pathway (controlled by MAGL) affected body temperature during challenges, while the anandamide pathway (controlled by FAAH) did not.
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Cite This Study
https://rethinkthc.com/research/RTHC-01025APA
Nass, Sara R; Long, Jonathan Z; Schlosburg, Joel E; Cravatt, Benjamin F; Lichtman, Aron H; Kinsey, Steven G. (2015). Endocannabinoid Catabolic Enzymes Play Differential Roles in Thermal Homeostasis in Response to Environmental or Immune Challenge.. Journal of neuroimmune pharmacology : the official journal of the Society on NeuroImmune Pharmacology, 10(2), 364-70. https://doi.org/10.1007/s11481-015-9593-1
MLA
Nass, Sara R, et al. "Endocannabinoid Catabolic Enzymes Play Differential Roles in Thermal Homeostasis in Response to Environmental or Immune Challenge.." Journal of neuroimmune pharmacology : the official journal of the Society on NeuroImmune Pharmacology, 2015. https://doi.org/10.1007/s11481-015-9593-1
RethinkTHC
RethinkTHC Research Database. "Endocannabinoid Catabolic Enzymes Play Differential Roles in..." RTHC-01025. Retrieved from https://rethinkthc.com/research/nass-2015-endocannabinoid-catabolic-enzymes-play
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 RethinkTHC 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.