Blood vessels and the endocannabinoid system
Adjusting vessel width.
Adjusting vessel width. Where the cannabinoid receptors CB1 and CB2 sit in this region, what they do there, and what is actually known about CBD; at three levels for Everyone, Students and Experts, with sources.
Blood vessels and skinCB1 high · CB2 very low (Human Protein Atlas)Last updated:
What's on this page?
Interactive 3D · real anatomy and real data
Where in your body are the cannabinoid receptors?
About 1.4 MB to download.
Regions
How to read it Choose a region, or tap a glowing point on the map.
- Solid light is the CB1 receptor, a ring is CB2. Each region has its own color; the color only tells regions apart.
- The strength of the light is the receptor gene level measured in human tissue (Human Protein Atlas). That is why the liver’s point is dim: a healthy liver has few receptors.
- With the layer selector above you can also see other receptors, the enzymes that make and break down endocannabinoids, and the liver enzymes that break down CBD and THC.
- Every piece of information shows its source and the type of evidence (human, animal, cell). You can change the reading level above.
- Drag to rotate. Use the + and − buttons to zoom; on a computer, Ctrl or ⌘ with the scroll wheel, on a phone, two fingers.
Blood vessel: RNA level of the receptor gene in human tissue (tissue consensus data). CB1 RNA is higher than in the basal ganglia (15.1) and hippocampus (13.2); CB2 is very low. Human Protein AtlasHuman tissue
| Receptor | Gene | RNA (nTPM) | Level |
|---|---|---|---|
| CB1 | CNR1 | 16.8 | high |
| CB2 | CNR2 | 0.1 | very low |
What does it do there?
RNA for the CB1 receptor is measured as high in blood vessel tissue; the value is even higher than in the basal ganglia and hippocampus. The cells lining the inside of blood vessels (endothelium) carry CB1. In pieces of artery taken from patients having bowel surgery, the body's own cannabinoid anandamide moderately relaxed the vessel through CB1 and the endothelium. Human Protein AtlasHuman tissueLiu 2000Cell / labStanley 2016Human tissueCell / lab
Most of what is known about the effects of cannabinoids on blood vessels comes from animal studies; some targets have also been confirmed in human arteries. In rats with high blood pressure, there was more CB1 in the heart and in the inner lining of the main artery (aorta). Stanley and O'Sullivan 2014ReviewBátkai 2004Animal
Student level: terms and cell types
RT-PCR and [125I]AM-251 binding showed CB1 in human aortic and hepatic artery endothelial cells; these receptors are coupled to the MAP kinase pathway. In mesenteric arteries from patients undergoing bowel resection (wire myography), anandamide relaxed the precontracted vessel by up to about 30%; the effect was reduced by removing the endothelium, by NO synthase inhibition and by CB1 antagonism, and did not change with CB2 antagonism. Human aortic endothelial cells had mRNA for CB1 but not for CB2. Human Protein AtlasHuman tissueLiu 2000Cell / labStanley 2016Human tissueCell / lab
According to a review, cannabinoids in blood vessels act directly on CB1 as well as on a proposed endothelial cannabinoid receptor, TRPV1 and PPARs; the roles of CB2, GPR55 and 5-HT1A stood out in some studies. Vascular responses were found to be increased in hypertension and cirrhosis and reduced in obesity and diabetes. In spontaneously hypertensive rats, CB1 was increased in the heart and aortic endothelium. Stanley and O'Sullivan 2014ReviewBátkai 2004Animal
Expert level: method notes and numbers
Blood vessel: RNA level of the receptor gene in human tissue (tissue consensus data). CB1 RNA is higher than in the basal ganglia (15.1) and hippocampus (13.2); CB2 is very low. Human Protein AtlasHuman tissue
Method note
Liu 2000: RT-PCR, [125I]AM-251 radioligand binding; human aortic and hepatic artery endothelial cells. Stanley 2016: 31 patients, wire myography; anandamide Rmax ≈ 30%, the synthetic CB1 agonist CP55940 Rmax ≈ 60%, the CB2 agonist HU308 without effect. Liu 2000Cell / labStanley 2016Human tissueCell / lab
Stanley and O'Sullivan 2014: review; most of the evidence comes from animal research. Bátkai 2004: spontaneously hypertensive rats and normotensive Wistar-Kyoto controls. Stanley and O'Sullivan 2014ReviewBátkai 2004Animal
The model shows the aorta and the main arteries (the carotid, subclavian, axillary, brachial, iliac, femoral and popliteal arteries).
What is known about CBD?
In the laboratory, in pieces of human mesenteric artery (the artery supplying the bowel), CBD relaxed the vessel by up to about 40%. This effect worked through CB1 and TRP channels and depended on the endothelium and nitric oxide. This is a tissue experiment. Stanley 2015Human tissueCell / lab
May help a little Weak evidence
In the guide: Blood Pressure and CBD
A small effect was seen in research, but this is not evidence of a treatment. If you are considering CBD, you can talk with your doctor or pharmacist, including about the medicines you take.
Which receptor and enzyme genes are read in this region?
Values in this region for the genes in the map's layer selector: besides CB1 and CB2, the other targets of cannabinoids, the enzymes that make and break down endocannabinoids, and the liver enzymes that break down CBD and THC.
| Gene | What does it do? | Here | Tissue where it is read the most |
|---|---|---|---|
| Receptors | |||
| CB1 CNR1 | Cannabinoid receptor | 16.8 | cerebral cortex (18.6) |
| CB2 CNR2 | Cannabinoid receptor | 0.1 | spleen (8.4) |
| TRPV1 | Heat and chili pepper sensor · ion channel | 6.7 | liver (21.8) |
| GPR55 | Long an "orphan" receptor · in the cell membrane | 0.0 | testis (4.4) |
| PPARγ PPARG | Gene switch · in the cell nucleus | 17.9 | adipose tissue (153.2) |
| 5-HT1A HTR1A | Serotonin receptor · in the cell membrane | 0.0 | hippocampal formation (6.1) |
| TRPV2 | Relative of TRPV1 · ion channel | 18.7 | lung (29.5) |
| Endocannabinoid enzymes | |||
| NAPE-PLD NAPEPLD | Makes anandamide | 3.7 | kidney (13.9) |
| FAAH | Breaks down anandamide | 4.2 | testis (46.0) |
| DAGLα DAGLA | Makes 2-AG | 0.7 | cerebral cortex (12.3) |
| DAGLβ DAGLB | Makes 2-AG | 5.8 | adrenal gland (15.2) |
| MGL MGLL | Breaks down 2-AG | 50.5 | adipose tissue (161.3) |
| ABHD6 | Breaks down 2-AG | 6.3 | liver (60.7) |
| ABHD12 | Breaks down 2-AG | 36.0 | epididymis (125.2) |
| Enzymes that break down CBD and THC | |||
| CYP3A4 | Breaks down CBD and THC | 0.0 | liver (3,367.1) |
| CYP2C19 | Breaks down CBD | 0.0 | liver (178.0) |
| CYP2C9 | Breaks down THC | 0.0 | liver (1,607.6) |
RNA level shows how much the gene is read in this tissue; it does not directly show the amount of protein or how active an enzyme is. Human Protein Atlas (layers)Human tissue
Identifiers and citation
- Blood vessels
- Blood Vessels · MeSH D001808 · UBERON 0001981 · Wikidata Q988343
- Receptors
- CB1 (CNR1, UniProt P21554) · CB2 (CNR2, UniProt P34972)
How to cite: cbd.school editorial team. Blood vessels and the endocannabinoid system. Endocannabinoid system 3D map, cbd.school. Last updated October 24, 2026. https://cbd.school/learn/endocannabinoid-system-map/damar/
The body model is derived from BodyParts3D (DBCLS, CC BY 4.0) and Z-Anatomy (CC BY-SA 4.0); receptor levels from Human Protein Atlas v25 (CC BY 4.0). The map, text and downloaded images are CC BY-SA 4.0. An independent expert review has not been done yet. All licenses
Other pages of the map
Overview: what the endocannabinoid system is, the feedback brake at the synapse, CBD's targets, lesson mode, data and licenses.
Sources
Show 7 references
- Human Protein Atlas v25: tissue RNA consensus data (rna_tissue_consensus.tsv, HPA and GTEx, nTPM) and brain region data (rna_brain_region_hpa.tsv, nTPM), CNR1 (ENSG00000118432) and CNR2 (ENSG00000188822); v25.proteinatlas.org, file date November 6, 2025, downloaded October 24, 2026. Uhlén M et al. Tissue-based map of the human proteome. Science. 2015;347(6220):1260419. License CC BY 4.0. PMID 25613900 · doi:10.1126/science.1260419 Human tissue
- Liu J, Gao B, Mirshahi F et al. Functional CB1 cannabinoid receptors in human vascular endothelial cells. Biochem J. 2000;346 Pt 3:835-40. PMID 10698714 · doi:10.1042/bj3460835 Cell / lab
- Stanley CP, Hind WH, Tufarelli C et al. The endocannabinoid anandamide causes endothelium-dependent vasorelaxation in human mesenteric arteries. Pharmacol Res. 2016;113(Pt A):356-363. PMID 27633407 · doi:10.1016/j.phrs.2016.08.028 Human tissueCell / lab
- Stanley C, O'Sullivan SE. Vascular targets for cannabinoids: animal and human studies. Br J Pharmacol. 2014;171(6):1361-78. PMID 24329566 · doi:10.1111/bph.12560 Review
- Bátkai S, Pacher P, Osei-Hyiaman D et al. Endocannabinoids acting at cannabinoid-1 receptors regulate cardiovascular function in hypertension. Circulation. 2004;110(14):1996-2002. PMID 15451779 · doi:10.1161/01.CIR.0000143230.23252.D2 Animal
- Stanley CP, Hind WH, Tufarelli C et al. Cannabidiol causes endothelium-dependent vasorelaxation of human mesenteric arteries via CB1 activation. Cardiovasc Res. 2015;107(4):568-78. PMID 26092099 · doi:10.1093/cvr/cvv179 Human tissueCell / lab
- Human Protein Atlas v25: tissue RNA consensus data (rna_tissue_consensus.tsv, HPA and GTEx, nTPM), the 17 genes in the map's layer selector: CNR1, CNR2, TRPV1, GPR55, PPARG, HTR1A, TRPV2, NAPEPLD, FAAH, DAGLA, DAGLB, MGLL, ABHD6, ABHD12, CYP3A4, CYP2C19, CYP2C9; v25.proteinatlas.org/download/tsv/rna_tissue_consensus.tsv.zip, downloaded October 24, 2026. Uhlén M et al. Tissue-based map of the human proteome. Science. 2015;347(6220):1260419. License CC BY 4.0. PMID 25613900 · doi:10.1126/science.1260419 Human tissue