A systematic comparison of 14 endocannabinoid receptors across seven organs in mice, rats, and macaques found no receptor with identical expression patterns across all three species.
Cannabinoid researchers, pharmacologists, translational scientists, drug developers
Zero of 14 endocannabinoid receptors matched across species
What the researchers found
Of 14 endocannabinoid receptors examined in seven peripheral organs, not a single receptor had identical expression patterns across mice, rats, and rhesus macaques. Species- and organ-specific heterogeneity was the norm.
Why it matters
Most cannabinoid research uses rodent models, but if receptor distribution differs fundamentally between species, findings may not predict effects in primates or humans.
The numbers in context
14 receptors; 7 organs; 3 species; 0 receptors with identical cross-species expression.
How the study worked
Quantitative gene expression analysis of 14 endocannabinoid receptors in seven peripheral organs of C57/BL6 mice (n=5), Sprague-Dawley rats (n=6), and rhesus macaques (n=4).
What this study cannot tell us
Small numbers of animals per species. Gene expression does not necessarily predict protein levels. Only peripheral organs, not CNS.
How to read the evidence
Systematic cross-species comparison, limited by small sample sizes and peripheral organs only.
When this study was published
2024 publication
The bigger picture
This identifies a previously unappreciated contributor to reproducibility challenges in cannabinoid research. The translational pipeline from rodent models to human therapies needs reconsideration.
Questions still open
- Do the same cross-species differences exist in the central nervous system?
- Should cannabinoid therapy development prioritize primate or human tissue models?
Common questions
Do animal studies of cannabis translate to humans?
Why is the endocannabinoid system different across species?
Read the original research
Roadmap for the expression of canonical and extended endocannabinoid system receptors and metabolic enzymes in peripheral organs of preclinical animal models.
Physiological reports, 12(4), e15947
Citation
Rosado-Franco, J J; Ellison, A L; White, C J; Price, A S; Moore, C F; Williams, R E; Fridman, L B; Weerts, E M; Williams, D W. (2024). Roadmap for the expression of canonical and extended endocannabinoid system receptors and metabolic enzymes in peripheral organs of preclinical animal models.. Physiological reports, 12(4), e15947. https://doi.org/10.14814/phy2.15947
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