pe
pep-04480 v1 CC-BY-SA-4.0

Neurotensin: brain-and-gut signaling hormone

A natural peptide made in the brain and gut that influences pain, appetite, digestion, and dopamine activity; used mainly as a lab research tool.

statusbioassayed targetNTSR1 length13 aa refs2
endogenous
status 2 / 5 · 0 verified on platform
prediction metrics boltz-2 1.0
ipTM0.816
pTM0.839
avg pLDDT76.0
ranking score0.771
STRUCTURE · PEP-04480 × NTSR1
ranking0.771
target interface 4.5Å peptide drag rotate · ctrl+scroll zoom · right-click pan
boltz-2 1.0 · mmCIF ↓ download
sequence13 aa
151013
QLYENKPRRPYIL
overview readme

What this is

Neurotensin is a 13-amino-acid peptide produced naturally in the brain and gut. First isolated from bovine hypothalamus, it acts as both a neuropeptide in the central nervous system and a hormone in the gastrointestinal tract, influencing pain perception, dopamine signaling, appetite, and digestion. It has drawn sustained research interest for its potential connections to psychiatric conditions, metabolic regulation, and cancer biology (Clynen and colleagues 2014; Petruzziello and colleagues 2012).

The stored sequence QLYENKPRRPYIL is the unmodified 13-residue human tridecapeptide. In biological systems, neurotensin is rapidly degraded by peptidases in the blood and at cell membranes — a short half-life that has driven the development of metabolically stabilized analogs for research and therapeutic purposes (Dobner 2006, cited in the pain modulation literature; 10.7150/thno.4024).

History

Neurotensin was isolated from bovine hypothalamus and later shown to be widely distributed across the nervous system and gastrointestinal tract. Research over the following decades established its presence as a co-transmitter alongside dopamine in midbrain neurons, its release from intestinal N-cells in response to fat ingestion, and its involvement in a range of physiological processes from pain modulation to glucose homeostasis. Early neurochemical work characterized two distinct membrane-associated degrading activities that rapidly cleave the peptide, with the endopeptidase inhibitor thiorphan shown to block the membrane-bound activity (10.1111/j.1471-4159.1983.tb04753.x). The cloning of the rat neurotensin receptor (later classified as NTS1/NTSR1) in 1990 opened the door to receptor-level pharmacology (referenced in 10.1016/j.ejphar.2015.05.025).

What it does

Neurotensin acts primarily at two G protein-coupled receptors, NTS1 (NTSR1) and NTS2, which are expressed in the brain, spinal cord, and peripheral organs. In the central nervous system, it modulates pain — intracisternal administration inhibits responsiveness to noxious stimuli in animal models, an effect that can be separated from opioid pathways (10.1113/jphysiol.2008.167429). It also influences dopamine neurotransmission in regions relevant to psychosis and reward, and neurotensin concentrations in cerebrospinal fluid have been correlated with symptoms and drug response in psychotic patients (10.1038/sj.mp.4000761).

In the periphery, neurotensin is released from gut endocrine cells and stimulates the exocrine pancreas, with fat-induced neurotensin release affecting pancreatic secretion (10.1159/000055831). It has also been found to support beta-cell survival in pancreatic islets and to participate in glucose homeostasis through neurotensin receptors on metabolic tissues (10.3389/fendo.2012.00184; 10.1111/bph.12953). Beyond these physiological roles, sustained or dysregulated neurotensin signaling has been linked to the proliferation of several tumor types, including gliomas and pancreatic carcinomas, acting through NTSR1 and downstream MAPK, PI3-kinase, and EGF-receptor pathways (10.1002/1878-0261.12815; 10.1016/j.ejphar.2017.03.046).

Evidence

  • Human: CSF neurotensin levels correlate with symptom severity and antipsychotic drug response in psychotic patients (Nemeroff and colleagues, cited in 10.1038/sj.mp.4000761). No clinical trials with exogenous neurotensin in humans have been reported in the dossier sources.
  • Animal: Intracisternal neurotensin inhibits nociceptive responses in mice; neurotensin (300 nM) reduces evoked inhibitory postsynaptic current amplitude in spinal cord preparations via a TRPV1-dependent mechanism (10.1113/jphysiol.2008.167429). Anticonvulsant effects observed in the 6 Hz corneal stimulation model; neurotensin levels reduced in cortex and hippocampus in the kainic acid epilepsy model (Clynen and colleagues 2014). Neurotensin-loaded PLGA/cellulose nanocrystal nanofibers accelerated wound healing in diabetic mice with sustained release over approximately two weeks (10.1208/s12249-025-03172-x).
  • In vitro: Neurotensin stimulates DNA synthesis in PC3 prostate cancer cells through MAP-kinase, PI3-kinase, and EGF-receptor pathways (Hassan and colleagues 2004, cited in 10.1016/j.ejphar.2017.03.046). Neurotensin promotes glioma cell progression through NTSR1 (Ouyang and colleagues 2015, cited in 10.1002/1878-0261.12815). Neurotensin receptor expression documented in pancreatic ductal carcinomas (Korner and colleagues 2015, cited in 10.1002/1878-0261.12815).

Known effects

  • Pain modulation — Preclinical (rodent intracisternal models); partially opioid-independent
  • Antipsychotic-related signaling — Correlational human CSF data; mechanistic preclinical work
  • Anticonvulsant activity — Preclinical (6 Hz corneal model)
  • Glucose homeostasis and beta-cell survival — Preclinical and mechanistic
  • Gut hormone / pancreatic stimulation — Preclinical and ex vivo
  • Tumor-proliferative signaling (NTSR1-mediated) — In vitro; glioma, pancreatic, prostate cancer models
  • Wound healing (nanofiber delivery) — Preclinical (diabetic mouse model)

Safety signals

No human clinical trial safety data for exogenous neurotensin administration appear in the dossier. The peptide is an endogenous signaling molecule. Its oncological role — promoting glioma and pancreatic cancer cell growth through NTSR1 — is noted across multiple in vitro studies (10.1002/1878-0261.12815; 10.1016/j.ejphar.2017.03.046) and has been flagged as a consideration for any therapeutic application targeting NTSR1 agonism.

Mechanism

Neurotensin binds to NTS1 (NTSR1) and NTS2, both G protein-coupled receptors. NTS1 is the higher-affinity receptor and is widely expressed in the CNS; NTS2 is implicated in antinociception and interacts functionally with opioid receptor pathways (10.1016/j.neuroscience.2010.08.016). In neurons, NTSR1 activation mobilizes intracellular calcium and can modulate inhibitory synaptic transmission — in spinal cord preparations, neurotensin reduces evoked IPSC amplitude through a mechanism requiring TRPV1 (10.1113/jphysiol.2008.167429). In peripheral tumor cells, NT signaling through NTSR1 activates MAPK, PI3-kinase, and EGF-receptor cascades to drive DNA synthesis and proliferation (10.1016/j.ejphar.2017.03.046).

The peptide is cleaved rapidly by both membrane-bound and soluble peptidases, with the endopeptidase inhibitor thiorphan blocking the membrane-bound activity — a degradation profile that limits the half-life of native neurotensin in vivo and has motivated the design of protease-resistant analogs (10.1111/j.1471-4159.1983.tb04753.x; 10.7150/thno.4024).

Related peptides

  • β-Lactotensin — A tetrapeptide fragment (HIRL) derived from bovine β-lactoglobulin that acts as a neurotensin receptor agonist, characterized as an endogenous food-derived NTS1 ligand (10.1271/bbb.67.940).
  • Cyclopsychotride A, a cyclic plant peptide from Psychotria longipes, has been characterized as a neurotensin antagonist in vitro (10.1105/tpc.104.021790), illustrating the receptor's tractability for small-molecule and peptide-based modulation.
Hypotheses3 directions▾ collapse

Research directions for this peptide, selected from the current sources — hypotheses you can explore and model. None of it is proven yet; tap any one to see the full thinking.

openupdated 2026-06-11

Could a stable neurotensin reduce both the drive to overeat and physical hunger by acting on the brain and gut at once?

If it works on both reward-driven cravings and hunger, it could help patients who do not respond fully to current weight-loss drugs.

The hypothesis
Neurotensin's established role as a co-transmitter with dopamine in midbrain neurons, combined with its gut-derived satiety signaling, positions NTSR1 agonism as a dual-mechanism intervention for both the hedonic and metabolic components of obesity, particularly in dopamine-reward-driven overeating.
Why it’s plausible
The readme explicitly links neurotensin to dopamine co-transmission in midbrain neurons and to fat-induced release from intestinal N-cells and glucose homeostasis. Reward-driven overeating depends heavily on mesolimbic dopamine circuits. An endogenous peptide that simultaneously dampens dopamine-driven hedonic drive (central) and signals gut satiety (peripheral) could address both dimensions of obesity that current GLP-1 agonists treat only partially.
Why it matters
If neurotensin analogs recapitulate this dual central-peripheral action, they could complement or outperform existing metabolic drugs in patients with compulsive eating disorders where mesolimbic dysregulation is prominent, opening a new mechanistic rationale for an already-studied peptide.
Plausibility.60
Novelty.45
Impact.60
Basis · grounding2 papers · 1 computed/note
[1]
noteNeurotensin is co-transmitter alongside dopamine in midbrain neurons; released from intestinal N-cells in response to fat ingestion; involved in glucose homeostasis
[2]
paper
Distribution and mechanism context includes appetite and metabolic regulation
doi: 10.1007/s12035-014-8669-x
[3]
paper
Pain modulation literature cites neurotensin analogs as research and therapeutic tools
doi: 10.7150/thno.4024
openupdated 2026-06-11

Does the branched shape of the final leucine fit the receptor specifically, or would any greasy amino acid do?

Knowing which features are required at the tail would tell drug designers how much they can change when building stable analogs.

The hypothesis
The Leu13 C-terminal residue of neurotensin acts as a hydrophobic anchor that inserts into a lipophilic pocket of NTSR1, and replacing it with norleucine versus other isosteres would reveal that the branched-chain geometry specifically is required for full agonist efficacy rather than mere hydrophobicity.
Why it’s plausible
The sequence ends in PYIL where I12 and L13 are consecutive aliphatic residues. C-terminal hydrophobic anchoring in peptide-GPCR binding is common. The boltz-2 ipTM of 0.816 suggests the C-terminus is well-engaged with the receptor. If L13 contributes via branched-chain shape rather than just hydrophobicity, then linear isosteres (norleucine, aminobutyric acid) would show graded loss of efficacy beyond what their polarity predicts.
Why it matters
Demonstrating that the branched geometry of Leu13 is required to complete the NTSR1 binding pose would explain why some reported neurotensin analogs with aliphatic substitutions at C-terminus show unexpectedly low potency, and would constrain which modifications are tolerable in drug design.
Plausibility.60
Novelty.50
Impact.50
Basis · grounding1 paper · 2 computed/notes
[1]
sequenceC-terminal residues I12 and L13 are consecutive branched aliphatic residues; L13 is the terminal anchor
[2]
structureipTM=0.816 indicates well-defined C-terminal engagement with NTSR1 binding pocket
[3]
paper
Peptide identity and evolutionary conservation context implies functional constraint on specific positions
doi: 10.1021/pr200709j
openupdated 2026-06-11

Could shielding the bond around neurotensin's arginine pair help it survive longer in the body while still hitting its receptor?

A longer-lasting neurotensin could become a non-addictive painkiller or psychiatric drug candidate, an alternative to opioids worth testing.

The hypothesis
Neurotensin's rapid enzymatic degradation by membrane-bound endopeptidase is the dominant half-life bottleneck in vivo, and protecting the Arg8-Arg9 dipeptide bond via backbone N-methylation would yield a systemically active analog with preserved NTSR1 potency.
Why it’s plausible
The readme explicitly notes two distinct membrane-associated degrading activities and names thiorphan (an endopeptidase inhibitor) as blocking one. The basic diarginine (RR at positions 8-9) is a canonical cleavage site for trypsin-like and furin-like enzymes. Backbone N-methylation at this site would sterically block protease access without altering the side chains that contact NTSR1, since the diarginine is in the PRRPY turn whose geometric constraints are already set by flanking prolines.
Why it matters
Demonstrating that a single backbone modification at RR extends plasma half-life while maintaining NTSR1 potency would provide a tractable path to a non-opioid analgesic or antipsychotic candidate without requiring full retro-inverso or peptidomimetic redesign.
Plausibility.70
Novelty.25
Impact.55
Basis · grounding1 paper · 2 computed/notes
[1]
noteRapidly degraded by peptidases in blood and at cell membranes; two membrane-associated degrading activities identified; thiorphan blocks membrane-bound endopeptidase
[2]
sequenceRR at positions 8-9 is a canonical trypsin/furin cleavage motif within the PRRPY segment
[3]
paper
Metabolically stabilized analogs for research and therapeutic purposes explicitly noted
doi: 10.7150/thno.4024
details expand to inspect
full evidence table2 metrics
metricvaluetool
ipTM 0.8160384893417358 boltz-2
ranking score 0.7710570693016052 boltz-2
structural qualityopenfold3
metricvaluenote
gpde0.906global PDE — lower = better
disorderNaNfraction disordered
3-letter notation
Gln-Leu-Tyr-Glu-Asn-Lys-Pro-Arg-Arg-Pro-Tyr-Ile-Leu
recipeboltz-2 1.0
parametervalue
modelboltz-2 1.0
weights
hardwarenvidia_nim_api
mlx version
python
random seed
msa strategynone
diffusion samples1
runtime
predicted bymlx@peptide
predicted at2026-04-24
citationbibtex
peptidemodel (2026). Neurotensin: brain-and-gut signaling hormone (pep-04480, v1). PeptideModel. https://peptidemodel.com/card/pep-04480
@peptide{pep04480,
  sequence = {QLYENKPRRPYIL},
  target   = {ntsr1},
  author   = {peptidemodel},
  year     = {2026},
  status   = {bioassayed}
}
related peptides 1 by signal overlap
clinical trials 48 on ct.gov · 2 on EUCTR · checked 2026-05-09
ct.gov trials 48
with results 2
EUCTR 2
PubMed RCT 7
by phase
1phase 31phase 48no phase
by status
7completed1not yet recruiting1withdrawn1unknown
references 2 papers
discussion no comments
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