Absorption from the stomach and small intestine: molecular mechanisms & dependencies

How nutrients influence it

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Human evidence only

How nutrients reach it in more than one step

Chains of two or more recorded steps that end here, grouped by the nutrient they start from. Each step is a separate finding, so a chain is a route a mechanism could take, not proof that it does.

Tracing routes…

What it does

Every recorded relationship this component is part of, grouped by its role. Plain wording comes first; the technical statement follows.

Recorded relationships

What acts on it

About 85% of the dose of capsaicin or dihydrocapsaicin was absorbed in the gastrointestinal tract within 3 hours in vivo, and in situ about 50, 80 and 70% of the dose disappeared from the lumen of stomach, jejunum and ileum within 60 minutes, while addition of 2,4-dinitrophenol or sodium cyanide produced no significant reduction in uptake of tritiated dihydrocapsaicin in the jejunum, suggesting absorption by a nonactive process.
Dihydrocapsaicin → Absorption from the stomach and small intestine source_derived_draftungraded
Experimental context and source evidence
evidence_span
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experimental_model
In vivo and in situ gastrointestinal absorption studies in rats with tritiated dihydrocapsaicin
exposure
Capsaicin and dihydrocapsaicin administered into stomach, jejunum and ileum, with 2,4-dinitrophenol and sodium cyanide as metabolic inhibitors
limitations
Establishes both the route and the first metabolite by direct measurement in portal blood. A 1984 rat study using tritium label rather than mass spectrometry.
nutrient_topic
Dihydrocapsaicin research collection; topical membership is not evidence of a direct clinical effect, and dihydrocapsaicin is recorded separately from capsaicin. · Dihydrocapsaicin
organism
Rat
plain_language
It crosses the gut wall quickly and without being pumped, mostly in the small intestine.
primary_references
[dhc-p6710495] Gastrointestinal absorption and metabolism of capsaicin and dihydrocapsaicin in rats. (1984). https://pubmed.ncbi.nlm.nih.gov/6710495/ DOI: 10.1016/0041-008x(84)90121-2
tissue_or_cell_type
Stomach, jejunum, ileum and portal blood
Dihydrocapsaicin: the second capsaicinoid, the hypothermia it is used to induce, what the gut and liver do to it, and what it does without TRPV1 (2026-09-21) · lines 478–489
AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · In vivo and in situ gastrointestinal absorption studies in rats with tritiated dihydrocapsaicin · source_derived_draft · unverified_draft
### dhc-absorbed-passively About 85% of the dose of capsaicin or dihydrocapsaicin was absorbed in the gastrointestinal tract within 3 hours in vivo, and in situ about 50, 80 and 70% of the dose disappeared from the lumen of stomach, jejunum and ileum within 60 minutes, while addition of 2,4-dinitrophenol or sodium cyanide produced no significant reduction in uptake of tritiated dihydrocapsaicin in the jejunum, suggesting absorption by a nonactive process. Condition category: normal nutrient_topic: Dihydrocapsaicin research collection; topical membership is not evidence of a direct clinical effect, and dihydrocapsaicin is recorded separately from capsaicin. plain_language: It crosses the gut wall quickly and without being pumped, mostly in the small intestine. organism: Rat tissue_or_cell_type: Stomach, jejunum, ileum and portal blood experimental_model: In vivo and in situ gastrointestinal absorption studies in rats with tritiated dihydrocapsaicin limitations: Establishes both the route and the first metabolite by direct measurement in portal blood. A 1984 rat study using tritium label rather than mass spectrometry. exposure: Capsaicin and dihydrocapsaicin administered into stomach, jejunum and ileum, with 2,4-dinitrophenol and sodium cyanide as metabolic inhibitors evidence_span: {"source_cache": "artifacts/dihydrocapsaicin-research/6710495.abstract.txt", "locator": "Indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "a0a9a5cb2178f2b266fffe5efbd9580a0a1b5c03dd86b4bfe92b105194eb1f9b", "start_char": 0, "end_char": 1416, "text_sha256": "a0a9a5cb2178f2b266fffe5efbd9580a0a1b5c03dd86b4bfe92b105194eb1f9b"} [dhc-p6710495] Gastrointestinal absorption and metabolism of capsaicin and dihydrocapsaicin in rats. (1984). https://pubmed.ncbi.nlm.nih.gov/6710495/ DOI: 10.1016/0041-008x(84)90121-2
Complete structured claim and evidence

Where it participates (unsigned role)

Tritiated dihydrocapsaicin and unlabelled capsaicin were readily absorbed from the gastrointestinal tract but were almost completely metabolized before reaching the general circulation, with less than 5% of total extracted radioactivity consisting of unchanged dihydrocapsaicin in trunk blood and brain 15 minutes after gastrointestinal application, against approximately 50% unchanged 3 minutes after intravenous or 90 minutes after subcutaneous application.
First-pass metabolism during and after absorption → Unchanged dihydrocapsaicin reaching trunk blood and brain source_derived_draftungraded
Experimental context and source evidence
availability_state
biomarker_context Imported condition classification; unverified.
evidence_span
{"source_cache": "artifacts/dihydrocapsaicin-research/2280802.abstract.txt", "locator": "Indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "92a4527b69cd4c342da3d0aed850597ef4491122baf20b6a681e43ab0a8e2dd1", "start_char": 0, "end_char": 1280, "text_sha256": "92a4527b69cd4c342da3d0aed850597ef4491122baf20b6a681e43ab0a8e2dd1"}
experimental_model
Intragastric, intravenous and subcutaneous administration of tritiated dihydrocapsaicin in anaesthetised rats with tissue extraction
exposure
Tritiated dihydrocapsaicin and unlabelled capsaicin given intragastrically, intravenously or subcutaneously
limitations
The comparison across routes is the point, and it is the reason every hypothermia study in this collection injects the drug rather than feeding it. Anaesthetised rats, and identification is chromatographic.
nutrient_topic
Dihydrocapsaicin research collection; topical membership is not evidence of a direct clinical effect, and dihydrocapsaicin is recorded separately from capsaicin. · Dihydrocapsaicin
organism
Rat
plain_language
Swallowed, almost none of it reaches the brain intact; injected, about half does.
primary_references
[dhc-p2280802] Absorption and metabolism of capsaicinoids following intragastric administration in rats. (1990). https://pubmed.ncbi.nlm.nih.gov/2280802/ DOI: 10.1007/bf00169449
tissue_or_cell_type
Portal blood, trunk blood, brain and liver
trigger_kind
biomarker_context Imported condition classification; unverified.
Dihydrocapsaicin: the second capsaicinoid, the hypothermia it is used to induce, what the gut and liver do to it, and what it does without TRPV1 (2026-09-21) · lines 504–515
AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Intragastric, intravenous and subcutaneous administration of tritiated dihydrocapsaicin in anaesthetised rats with tissue extraction · source_derived_draft · unverified_draft
### dhc-first-pass-destroys-it Tritiated dihydrocapsaicin and unlabelled capsaicin were readily absorbed from the gastrointestinal tract but were almost completely metabolized before reaching the general circulation, with less than 5% of total extracted radioactivity consisting of unchanged dihydrocapsaicin in trunk blood and brain 15 minutes after gastrointestinal application, against approximately 50% unchanged 3 minutes after intravenous or 90 minutes after subcutaneous application. Condition category: biomarker_context nutrient_topic: Dihydrocapsaicin research collection; topical membership is not evidence of a direct clinical effect, and dihydrocapsaicin is recorded separately from capsaicin. plain_language: Swallowed, almost none of it reaches the brain intact; injected, about half does. organism: Rat tissue_or_cell_type: Portal blood, trunk blood, brain and liver experimental_model: Intragastric, intravenous and subcutaneous administration of tritiated dihydrocapsaicin in anaesthetised rats with tissue extraction limitations: The comparison across routes is the point, and it is the reason every hypothermia study in this collection injects the drug rather than feeding it. Anaesthetised rats, and identification is chromatographic. exposure: Tritiated dihydrocapsaicin and unlabelled capsaicin given intragastrically, intravenously or subcutaneously evidence_span: {"source_cache": "artifacts/dihydrocapsaicin-research/2280802.abstract.txt", "locator": "Indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "92a4527b69cd4c342da3d0aed850597ef4491122baf20b6a681e43ab0a8e2dd1", "start_char": 0, "end_char": 1280, "text_sha256": "92a4527b69cd4c342da3d0aed850597ef4491122baf20b6a681e43ab0a8e2dd1"} [dhc-p2280802] Absorption and metabolism of capsaicinoids following intragastric administration in rats. (1990). https://pubmed.ncbi.nlm.nih.gov/2280802/ DOI: 10.1007/bf00169449
Complete structured claim and evidence

The events it takes part in

A mechanism often involves more than two components. These are the full events, with every participant and its role.

Situations it appears in

Low-supply and faulty-machinery situations recorded in the chapters where this component plays a part.

In the sources

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Open hypotheses

Proposed ideas that involve this component. They are labeled as hypotheses and do not change any recorded statement.

This is a research prototype built from draft material. It is not medical advice, and its statements still await verification against the original studies.

Absorption from the stomach and small intestine