> Trialight public data. Index of pages: https://trialight.com/llms.txt
> Web page: https://trialight.com/data/target/htr3a-fe582ba5-f417-57ec-ba38-176d118be59f
> Record changed: 2026-11-04

# HTR3A

ENSG00000166736

Target class

Ion channel

Chromosome

11

Approved drugs

13

Clinical candidates (approved and in development)

21

## Clinical evidence

**Approved drugs**

13

**Clinical candidates (approved and in development)**

21

## Druggability

**Chemical probe available**

Yes

## Names

**Target name**

HTR3A

**Gene name**

5-hydroxytryptamine receptor 3A

**Gene symbol**

HTR3A

**Previous gene symbols**

- HTR3

**Protein name**

5-hydroxytryptamine receptor 3A (5-HT3-A) (5-HT3A) (5-hydroxytryptamine receptor 3) (5-HT-3) (5-HT3R) (Serotonin receptor 3A) (Serotonin-gated ion channel receptor)

### Other names (2)

- 5-HT3R
- 5-HT3A

## Classification

**Gene biotype**

Protein coding

**Gene family**

5-hydroxytryptamine receptors, ionotropic

**Target class**

Ion channel

**Target type**

Human gene

## Expression and localisation

**Tissues expressed in**

6

**Highest tissue expression**

2.82

**Tissue specificity (Gini)**

0.717

**Tissue specificity (tau)**

0.876

## Pathways and interactions

**KEGG gene identifiers**

- hsa:3359

**Reactome pathways**

- R-HSA-112314

**Protein interaction confidence**

0.794105

**Protein interaction partners**

38

## Genomic location

**End position**

113990313

**Start position**

113975075

**Chromosome**

11

**Strand**

Forward

## Identifiers

**Ensembl gene ID**

ENSG00000166736

**HGNC ID**

HGNC:5297

Source: [www.genenames.org](https://www.genenames.org/data/gene-symbol-report/#!/hgnc%5Fid/HGNC:5297)

**NCBI Gene ID**

3359

**UniProt ID**

P46098

## Cellular location

- Postsynaptic cell membrane
- Multi-pass membrane protein . Cell membrane
- Multi-pass membrane protein .

### Publication evidence

- PubMed 9950429  
Source: [pubmed.ncbi.nlm.nih.gov](https://pubmed.ncbi.nlm.nih.gov/9950429/)

## Tissue expression

**Tissue specificity (tau)**

0.875753

**Expression inequality (Gini)**

0.716664

### Highest expression

Expression in transcripts per million

**Colon - Sigmoid**

2.82

**Brain - Caudate (basal ganglia)**

2.42

**Small Intestine - Terminal Ileum**

2.05

**Minor Salivary Gland**

1.6

**Colon - Transverse**

1.38

### All tissues (54)

Expression in transcripts per million

- Colon - Sigmoid2.82
- Brain - Caudate (basal ganglia)2.42
- Small Intestine - Terminal Ileum2.05
- Minor Salivary Gland1.6
- Colon - Transverse1.38
- Brain - Nucleus accumbens (basal ganglia)1.21
- Brain - Hippocampus0.97
- Brain - Putamen (basal ganglia)0.89
- Brain - Anterior cingulate cortex (BA24)0.85
- Esophagus - Muscularis0.82
- Brain - Amygdala0.72
- Pancreas0.71
- Brain - Cortex0.67
- Skin - Sun Exposed (Lower leg)0.63
- Spleen0.61
- Brain - Frontal Cortex (BA9)0.55
- Stomach0.52
- Esophagus - Gastroesophageal Junction0.37
- Testis0.33
- Bladder0.13
- Skin - Not Sun Exposed (Suprapubic)0.11
- Esophagus - Mucosa0.09
- Fallopian Tube0.09
- Vagina0.07
- Cervix - Endocervix0.06

And 29 more, listed on the interactive page.

## Biological functions

### Biological processes (3)

- GO:0007210  
Source: [www.ebi.ac.uk](https://www.ebi.ac.uk/QuickGO/term/GO:0007210)
- GO:0055085  
Source: [www.ebi.ac.uk](https://www.ebi.ac.uk/QuickGO/term/GO:0055085)
- GO:0140227  
Source: [www.ebi.ac.uk](https://www.ebi.ac.uk/QuickGO/term/GO:0140227)

### Cellular components (3)

- GO:0005886  
Source: [www.ebi.ac.uk](https://www.ebi.ac.uk/QuickGO/term/GO:0005886)
- GO:0032154  
Source: [www.ebi.ac.uk](https://www.ebi.ac.uk/QuickGO/term/GO:0032154)
- GO:1904602  
Source: [www.ebi.ac.uk](https://www.ebi.ac.uk/QuickGO/term/GO:1904602)

### Molecular functions (3)

- GO:0005515  
Source: [www.ebi.ac.uk](https://www.ebi.ac.uk/QuickGO/term/GO:0005515)
- GO:0022850  
Source: [www.ebi.ac.uk](https://www.ebi.ac.uk/QuickGO/term/GO:0022850)
- GO:0051378  
Source: [www.ebi.ac.uk](https://www.ebi.ac.uk/QuickGO/term/GO:0051378)

## On-target safety

- decreased memory  
### Effects

  - Activation/Increase/Upregulation: acute  
### Studies

  - preclinical: decreased memory  
### Biological samples (3)

  - central nervous system
  - cardiovascular
  - gastrointestinal  
PubMed 28216264  
Source: [pubmed.ncbi.nlm.nih.gov](https://pubmed.ncbi.nlm.nih.gov/28216264/)
- vomiting  
### Effects

  - Activation/Increase/Upregulation: acute  
### Studies

  - preclinical: vomiting  
### Biological samples (3)

  - central nervous system
  - cardiovascular
  - gastrointestinal  
PubMed 28216264  
Source: [pubmed.ncbi.nlm.nih.gov](https://pubmed.ncbi.nlm.nih.gov/28216264/)
- increased gastrointestinal transit  
### Effects

  - Activation/Increase/Upregulation: acute  
### Studies

  - preclinical: increased gastrointestinal transit  
### Biological samples (3)

  - central nervous system
  - cardiovascular
  - gastrointestinal  
PubMed 28216264  
Source: [pubmed.ncbi.nlm.nih.gov](https://pubmed.ncbi.nlm.nih.gov/28216264/)
- decreased pain  
### Effects

  - Inhibition/Decrease/Downregulation: acute  
### Studies

  - preclinical: decreased pain  
### Biological samples (3)

  - central nervous system
  - cardiovascular
  - gastrointestinal  
PubMed 28216264  
Source: [pubmed.ncbi.nlm.nih.gov](https://pubmed.ncbi.nlm.nih.gov/28216264/)
- constipation  
### Effects

  - Inhibition/Decrease/Downregulation: acute  
### Studies

  - preclinical: constipation  
### Biological samples (3)

  - central nervous system
  - cardiovascular
  - gastrointestinal  
PubMed 28216264  
Source: [pubmed.ncbi.nlm.nih.gov](https://pubmed.ncbi.nlm.nih.gov/28216264/)
- hard stool  
### Effects

  - Inhibition/Decrease/Downregulation: acute  
### Studies

  - preclinical: hard stool  
### Biological samples (3)

  - central nervous system
  - cardiovascular
  - gastrointestinal  
PubMed 28216264  
Source: [pubmed.ncbi.nlm.nih.gov](https://pubmed.ncbi.nlm.nih.gov/28216264/)
- drug abuse/dependence  
### Effects

  - Activation/Increase/Upregulation: acute  
### Studies

  - preclinical: drug abuse/dependence  
### Biological samples (3)

  - central nervous system
  - cardiovascular
  - gastrointestinal  
PubMed 28216264  
Source: [pubmed.ncbi.nlm.nih.gov](https://pubmed.ncbi.nlm.nih.gov/28216264/)
- decreased inflammation  
### Effects

  - Inhibition/Decrease/Downregulation: acute  
### Studies

  - preclinical: decreased inflammation  
### Biological samples (3)

  - central nervous system
  - cardiovascular
  - gastrointestinal  
PubMed 28216264  
Source: [pubmed.ncbi.nlm.nih.gov](https://pubmed.ncbi.nlm.nih.gov/28216264/)
- increased blood pressure  
### Effects

  - Activation/Increase/Upregulation: acute  
### Studies

  - preclinical: increased blood pressure  
### Biological samples (3)

  - central nervous system
  - cardiovascular
  - gastrointestinal  
PubMed 28216264  
Source: [pubmed.ncbi.nlm.nih.gov](https://pubmed.ncbi.nlm.nih.gov/28216264/)
- abdominal distension  
### Effects

  - Inhibition/Decrease/Downregulation: acute  
### Studies

  - preclinical: abdominal distension  
### Biological samples (3)

  - central nervous system
  - cardiovascular
  - gastrointestinal  
PubMed 28216264  
Source: [pubmed.ncbi.nlm.nih.gov](https://pubmed.ncbi.nlm.nih.gov/28216264/)
- dizziness  
### Effects

  - Inhibition/Decrease/Downregulation: acute  
### Studies

  - preclinical: dizziness  
### Biological samples (3)

  - central nervous system
  - cardiovascular
  - gastrointestinal  
PubMed 28216264  
Source: [pubmed.ncbi.nlm.nih.gov](https://pubmed.ncbi.nlm.nih.gov/28216264/)
- increased gastric emptying  
### Effects

  - Activation/Increase/Upregulation: acute  
### Studies

  - preclinical: increased gastric emptying  
### Biological samples (3)

  - central nervous system
  - cardiovascular
  - gastrointestinal  
PubMed 28216264  
Source: [pubmed.ncbi.nlm.nih.gov](https://pubmed.ncbi.nlm.nih.gov/28216264/)
- increased heart rate  
### Effects

  - Activation/Increase/Upregulation: acute  
### Studies

  - preclinical: increased heart rate  
### Biological samples (3)

  - central nervous system
  - cardiovascular
  - gastrointestinal  
PubMed 28216264  
Source: [pubmed.ncbi.nlm.nih.gov](https://pubmed.ncbi.nlm.nih.gov/28216264/)
- ischemic colitis  
### Effects

  - Inhibition/Decrease/Downregulation: acute  
### Studies

  - preclinical: ischemic colitis  
### Biological samples (3)

  - central nervous system
  - cardiovascular
  - gastrointestinal  
PubMed 28216264  
Source: [pubmed.ncbi.nlm.nih.gov](https://pubmed.ncbi.nlm.nih.gov/28216264/)
- decreased anxiety  
### Effects

  - Inhibition/Decrease/Downregulation: acute  
### Studies

  - preclinical: decreased anxiety  
### Biological samples (3)

  - central nervous system
  - cardiovascular
  - gastrointestinal  
PubMed 28216264  
Source: [pubmed.ncbi.nlm.nih.gov](https://pubmed.ncbi.nlm.nih.gov/28216264/)
- increased memory  
### Effects

  - Inhibition/Decrease/Downregulation: acute  
### Studies

  - preclinical: increased memory  
### Biological samples (3)

  - central nervous system
  - cardiovascular
  - gastrointestinal  
PubMed 28216264  
Source: [pubmed.ncbi.nlm.nih.gov](https://pubmed.ncbi.nlm.nih.gov/28216264/)
- decreased gastrointestinal transit  
### Effects

  - Inhibition/Decrease/Downregulation: acute  
### Studies

  - preclinical: decreased gastrointestinal transit  
### Biological samples (3)

  - central nervous system
  - cardiovascular
  - gastrointestinal  
PubMed 28216264  
Source: [pubmed.ncbi.nlm.nih.gov](https://pubmed.ncbi.nlm.nih.gov/28216264/)
- apnea  
### Effects

  - Activation/Increase/Upregulation: acute  
### Studies

  - preclinical: apnea  
### Biological samples (3)

  - central nervous system
  - cardiovascular
  - gastrointestinal  
PubMed 28216264  
Source: [pubmed.ncbi.nlm.nih.gov](https://pubmed.ncbi.nlm.nih.gov/28216264/)

## Off-target safety

- gastric emptying  
### Effects

  - Activation/Increase/Upregulation: general  
### Studies

  - preclinical: gastric emptying  
### Biological samples (2)

  - endocrine
  - gastrointestinal  
PubMed 23197038  
Source: [pubmed.ncbi.nlm.nih.gov](https://pubmed.ncbi.nlm.nih.gov/23197038/)
- constipation  
### Effects

  - Inhibition/Decrease/Downregulation: general  
### Studies

  - preclinical: constipation  
### Biological samples (2)

  - endocrine
  - gastrointestinal  
PubMed 23197038  
Source: [pubmed.ncbi.nlm.nih.gov](https://pubmed.ncbi.nlm.nih.gov/23197038/)
- possible increased heart rate  
### Effects

  - Activation/Increase/Upregulation: general  
### Studies

  - preclinical: possible increased heart rate  
### Biological samples (2)

  - endocrine
  - gastrointestinal  
PubMed 23197038  
Source: [pubmed.ncbi.nlm.nih.gov](https://pubmed.ncbi.nlm.nih.gov/23197038/)
- receptor binding  
### Studies

  - biochemical: NVS\_LGIC\_h5HT3, is one of one assay component(s) measured or calculated from the NVS\_LGIC\_h5HT3 assay. It is designed to make measurements of radioligand binding, a form of binding reporter, as detected with scintillation counting signals by Filter-based radiodetection technology.  
### Biological samples

  - cell-free  
Evidence source  
Source: [www.epa.gov](https://www.epa.gov/chemical-research/exploring-toxcast-data-downloadable-data)
- dizziness  
### Effects

  - Inhibition/Decrease/Downregulation: general  
### Studies

  - preclinical: dizziness  
### Biological samples (2)

  - endocrine
  - gastrointestinal  
PubMed 23197038  
Source: [pubmed.ncbi.nlm.nih.gov](https://pubmed.ncbi.nlm.nih.gov/23197038/)
- emesis  
### Effects

  - Activation/Increase/Upregulation: general  
### Studies

  - preclinical: emesis  
### Biological samples (2)

  - endocrine
  - gastrointestinal  
PubMed 23197038  
Source: [pubmed.ncbi.nlm.nih.gov](https://pubmed.ncbi.nlm.nih.gov/23197038/)
- hyperglycaemia  
### Effects

  - Activation/Increase/Upregulation: general  
### Studies

  - preclinical: hyperglycaemia  
### Biological samples (2)

  - endocrine
  - gastrointestinal  
PubMed 23197038  
Source: [pubmed.ncbi.nlm.nih.gov](https://pubmed.ncbi.nlm.nih.gov/23197038/)

## Related records

### Trials (1,122)

- "Olanzapine for Prevention of Chemotherapy Induced Nausea and Vomiting in Children and Adolescents Receiving Highly Emetogenic Chemotherapy (HEC)"
- "THINK Trial: Treatment of Headache With IntraNasal Ketamine: A Randomized Controlled Trial Evaluating the Efficacy of Intranasal Ketamine Versus Standard Therapy in the Management of Primary Headache Syndromes in the Emergency Department"
- 2 Doses of an Approved Drug Being Studied for a New Indication for the Prevention of Postoperative Nausea and Vomiting (0869-090)(COMPLETED)
- 2 Doses of an Approved Drug Being Studied for a New Indication for the Prevention of Postoperative Nausea and Vomiting (0869-091)
- 5-HT3 Antagonists (Antiemetics) and Cardiac Safety
- 5-HT3 Receptor Antagonist (Ramosetron) vs Loperamide for the Treatment of Low Anterior Resection Syndrome(RALARS)
- 5-HT3 Receptor Antagonist and Respiratory Drive in Patients With ARDS
- 5HT3 Antagonism and Auditory Gating in Schizophrenia
- 5HT3 Antagonists to Treat Opioid Withdrawal and to Prevent the Progression of Physical Dependence
- A 10-Week, Open-Label, Flexible Dose Adaptive Study Evaluating the Efficacy of Vortioxetine in Subjects With Panic Disorder
- A Bioequivalence Study of 3 Formulations of Ondansetron in Healthy Adults (0869-095)(COMPLETED)
- A Bioequivalence Study of the Lu AA21004 20 mg and 2×10 mg Tablets
- A Clinical Study of MK-4318 and Diltiazem in Healthy People (MK-4318-003)
- A Clinical Trial Analyzing Effects of Prokinetic Drug on the Blood Glucose in Patients With Type 2 Diabetes
- [A Clinical Trial of HRS5580 for Injection Combined With Palonosetron Hydrochloride for the Prevention of Postoperative Nausea and Vomiting](https://trialight.com/data/trial/a-clinical-trial-of-hrs5580-for-injection-combined-with-52322000-5d1d-42bb-bfa1-d0e59c054124.md)
- A Clinical Trial of MK-4082 in Healthy Participants (MK-4082-005)
- A Cohort Study Evaluating the Efficacy of PO Magnesium in the Treatment of Acute Traumatic Brain Injury in Adolescents
- A Cohort Study on the Prevention of Nausea and Vomiting Induced by Concurrent Chemoradiotherapy for Lung Cancer Using Rolapitant and Palonosetron
- A Comparative Evaluation of Mosapride Versus Metoclopramide for Enteral Feeding Intolerance in Critically Ill Patients
- A COMPARATIVE STUDY BETWEEN 1MG AND 3 MG OF GRANISETRON IN THE PREVENTION OF POSTOPERATIVE NAUSEA AND VOMITING IN STRABISMUS OPHTHALMIC SURGERIES DURING GENERAL ANESTHESIA

### Drugs (44)

- Alosetron Serotonin 3a (5-HT3a) receptor antagonist
- Alosetron hydrochloride Serotonin 3a (5-HT3a) receptor antagonist
- Amisulpride Serotonin (5-HT) receptor antagonist
- Azasetron
- AZD0328
- Cilansetron Serotonin 3 (5-HT3) receptor antagonist
- Cilansetron hydrochloride Serotonin 3 (5-HT3) receptor antagonist
- Clothiapine Serotonin 3 (5-HT3) receptor antagonist
- Cocaine
- Dexfenfluramine Serotonin (5-HT) receptor agonist
- Dexfenfluramine hydrochloride Serotonin (5-HT) receptor agonist
- Diltiazem
- Dolasetron Serotonin 3a (5-HT3a) receptor antagonist
- Dolasetron mesylate Serotonin 3a (5-HT3a) receptor antagonist
- Facinicline Serotonin 3 (5-HT3) receptor antagonist
- Facinicline hydrochloride Serotonin 3 (5-HT3) receptor antagonist
- Granisetron Serotonin 3a (5-HT3a) receptor antagonist
- Granisetron hydrochloride Serotonin 3a (5-HT3a) receptor antagonist
- Indisetron
- Metoclopramide Serotonin 3a (5-HT3a) receptor antagonist

---

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