histamine
Enable an agent to recognise histamine, assess its chemical and biological context, and determine appropriate measurement, handling and use.
Research draft, second pass
A second pass drafted this model: the structure a model of this thing needs, and what is known about it in the world. The line under this one says how the second half was obtained - researched against sources, or recalled without web access, in which case nothing here was read anywhere and every claim is a lead to verify. Unreviewed either way.
recalled by Codex without web access - no source was read
Researched by: Codex
Purpose and description
Enable an agent to recognise histamine, assess its chemical and biological context, and determine appropriate measurement, handling and use.
Histamine is a biogenic amine formed by decarboxylation of histidine that acts through histamine receptors as a mediator of immune responses, gastric acid secretion and neurotransmission.
It can be Resolve whether a record describes histamine free base, a named salt or histamine within a mixture.; Convert reported amounts to a common histamine basis when composition and reporting conventions are verified.; Select and assess sampling and analytical methods appropriate to the matrix and required sensitivity.; Relate changes in histamine concentration to supported formation, release or degradation pathways.; Evaluate whether a histamine sample is suitable for a specified analytical or biological experiment.; Determine applicable handling instructions and flag measurements requiring specialist interpretation..
Distinguishing features
Histamine has an imidazole ring with an aminoethyl side chain; a candidate identity must match this connectivity rather than merely contain an imidazole group.
Histamine lacks the carboxyl group present in its precursor histidine, so histidine content cannot be recorded as histamine content.
A histamine salt includes counterions and has a different formula mass from histamine free base; its weighed mass cannot be treated as an equal mass of free base.
An antihistamine is identified through its own chemical identity and pharmacological action, not classified as histamine because its name or use refers to histamine.
Histamine detected in food and histamine released by cells share a chemical identity, but their origin and exposure context require separate records.
Scope
+ Histamine identity, molecular structure, protonation state and distinction from salts and formulated products
+ Composition, purity, concentration and physical condition of histamine-containing samples
+ Histamine formation, metabolism and receptor-mediated activity as relations to biological processes
+ Measurement of histamine in chemical, biological and food matrices
+ Evidence governing storage, handling and interpretation of histamine exposure
- Complete models of histidine, antihistamines and other biogenic amines
- Diseases and clinical diagnoses associated with histamine
- Foods, medicines and laboratory products as complete products
- Full models of histamine receptors, cells, organisms and microbial species
- Manufacturing processes and clinical treatment protocols
Characteristics
- Chemical identity
- Verified structure, molecular formula and form-specific CAS, PubChem and EC identifiers where available Prevents confusion between histamine, its salts, precursors and similarly named compounds.
- Material form and protonation context
- Free base or named salt; counterion stoichiometry; hydration state; solution pH Determines mass conversion, solution behaviour and applicability of reference properties.
- Histamine concentration
- mol/L, mass/volume or mass/mass with matrix and free-base-equivalent or salt basis specified Makes quantities comparable and supports preparation, exposure assessment and interpretation.
- Purity and impurity profile
- Assay percentage with method and reporting basis; identified impurities and their amounts Determines suitability for analytical or experimental use and identifies potential confounders.
- Physical properties under stated conditions
- Phase; melting or decomposition temperature in °C; solubility in g/L or mol/L with solvent, pH and temperature Supports preparation and storage without transferring properties between incompatible material forms.
- Sample matrix
- Neat material, prepared solution, food, biological fluid, tissue or other specified matrix Controls sampling, extraction, analytical interference and interpretation.
- Formation and removal context
- Documented links to histidine decarboxylation, cellular release, uptake or metabolic degradation Helps explain whether a measured amount represents accumulation, release or clearance.
- Receptor and response context
- H1, H2, H3 or H4 receptor; species, tissue, assay and measured response Prevents biological effects observed in one system from being treated as universal properties.
- Analytical confidence
- Detection and quantification limits, recovery, precision and uncertainty in method-appropriate units Distinguishes reliable quantification from tentative identification or an unquantifiable signal.
- Applicable hazard and decision status
- Verified form-specific hazard classification and context-specific criteria, with source, jurisdiction and date Connects actions to applicable evidence rather than assuming one universal histamine safety threshold.
Where this came from
wikidata · CC0 1.0
Drafted structure
Bundle to layer to finding to question, as the second pass will find it: 6 bundles · 11 layers · 18 findings · 28 questions.
Histamine identity and form Establishes the chemical entity and the material form actually represented.
Histamine, histidine and histamine salts can be confused in names, identifiers and quantity calculations.
Molecular recognition
Recognises histamine through chemical structure and supported identifiers.
Histamine structural boundary
Recognition requires histamine connectivity and explicit exclusion of precursors, metabolites and receptor-blocking compounds.
- What verified structure and identifiers establish that the entity is histamine? definition
- Does this record instead describe histidine, a histamine metabolite or an antihistamine? boundary
Salt and solution form
Separates supplied material identity from histamine species present in solution.
Histamine quantity basis
Amounts must distinguish free base, salt mass and histamine-equivalent content, with solution conditions recorded separately.
- Is the material free base or a specified salt, and what counterion, hydration state and stoichiometry are documented? definition
- Are reported quantities based on the supplied material or histamine equivalents, and what verified conversion applies? measurement
Histamine material fitness Assesses the composition and condition of histamine material intended for measurement or use.
Form, impurities and solution conditions can change the meaning of a nominal histamine amount and the suitability of a sample.
Assay and impurities
Establishes how much histamine is present and what accompanies it.
Usable histamine content
Sample fitness depends on an assay with a clear reporting basis and relevant impurity information.
- What assay establishes histamine content, and does its percentage refer to dry material, supplied material or another basis? measurement
- Which residual precursors, other amines, solvents or counterions could interfere with the intended use? action
Physical condition and storage
Records properties and storage evidence for the particular histamine form or preparation.
Form-specific property evidence
Solubility, phase transitions and stability claims must identify material form and experimental conditions.
- What measured phase, solubility and melting or decomposition behaviour apply to this histamine form under stated conditions? measurement
- What evidence supports the storage conditions and usable lifetime of this solid or prepared histamine solution? provenance
Histamine biological context Connects histamine to its formation, removal and receptor-dependent effects.
Chemical identity alone cannot explain where histamine came from or what a particular concentration means biologically.
Formation, release and removal
Distinguishes production from release of existing stores and subsequent metabolism.
Histamine origin and fate
Changes in histamine amount require context about histidine conversion, cellular release and removal pathways.
- What evidence attributes the histamine to endogenous synthesis, cellular release, microbial formation or external addition? provenance
- Which formation or removal processes could change histamine between the event of interest and measurement? measurement
Receptor-dependent response
Locates biological activity within a defined receptor, tissue and experimental system.
Bounded histamine effect
An observed histamine response belongs to its tested concentration, duration and biological context.
- Which histamine receptor subtype, species, tissue and response endpoint are implicated by the evidence? definition
- What concentration and exposure duration produced the response, and what limits transfer to another biological setting? boundary
Histamine detection and quantification Establishes whether analytical results identify and quantify histamine reliably.
Histamine measurements depend on matrix, sampling history, selectivity and reporting conventions.
Sampling and matrix
Captures the origin and handling of the portion submitted for analysis.
Representative histamine sample
A result must retain its matrix and sampling history to represent the intended material or biological event.
- What food portion, fluid, tissue or chemical preparation was sampled, and how representative is it of the target? provenance
- How were collection timing, temperature, preservation and extraction controlled to limit changes in histamine content? measurement
Analytical selectivity and reporting
Evaluates identification, calibration and uncertainty in the reported histamine result.
Defensible histamine result
A defensible result distinguishes histamine from interfering compounds and states the limits of quantification.
- How does the method distinguish histamine from histidine, other biogenic amines and matrix interference? measurement
- What calibration traceability, recovery, quantification limit and uncertainty support the reported value and units? measurement
Histamine handling and decisions Connects material hazards and measured histamine to justified actions in a specific use context.
Laboratory handling, food assessment and biological interpretation require different evidence and cannot share an assumed universal threshold.
Material hazard and use
Establishes handling requirements for the supplied form and intended operation.
Applicable histamine handling
Handling decisions require a current safety source that matches the actual substance form or mixture.
- Which safety data and hazard classification apply to this histamine form, concentration and jurisdiction? provenance
- What handling, storage and disposal measures follow for the intended preparation or experiment? action
Exposure and interpretation
Separates analytical observations from conclusions about exposure, compliance or health.
Context-specific histamine decision
A histamine measurement supports a decision only when the relevant matrix, exposure and interpretation criteria are established.
- What route, amount, timing and sample context connect the measured histamine to the proposed decision? boundary
- Which verified regulatory criterion, validated reference interval or experimental acceptance rule applies, and what action does it support? action
Evidence and external alignment What the world already says about this thing, gathered so the model can be checked against it.
A model that cannot be lined up against existing standards, identifiers and practice cannot be adopted by anyone who already uses them.
Reported evidence
Findings from the breadth pass, kept separate from the structural claims.
Check these first
Recalled without web access and unsourced; every item is a lead to verify.
- This is recalled knowledge, not a source-verified account.
- Physical constants, purity specifications and hazard classifications must be checked for the particular free base or salt.
- Applicable food limits, analytical methods and medicinal preparation requirements need jurisdiction-specific verification.
- Which of these check these first hold for the sense of histamine this model covers, and on what evidence? provenance
Kinds and varieties
Recalled without web access and unsourced; every item is a lead to verify.
- Histamine free base
- Histamine dihydrochloride, a salt form
- Which of these kinds and varieties hold for the sense of histamine this model covers, and on what evidence? provenance
Identifiers and schemes
Recalled without web access and unsourced; every item is a lead to verify.
- CAS Registry Number - 51-45-6 - Identifies histamine free base; salts have separate identifiers.
- PubChem CID - 774 - Compound record for histamine.
- Molecular formula - C5H9N3 - Formula of the neutral molecule; not a unique structural identifier.
- Which of these identifiers and schemes hold for the sense of histamine this model covers, and on what evidence? provenance
Real-world use
Recalled without web access and unsourced; every item is a lead to verify.
- Positive control in allergy skin testing using formulated histamine preparations.
- Experimental reagent for studying histamine receptors and their physiological effects.
- Analytical reference material for measuring histamine in food and biological samples.
- Food safety testing target, particularly in fish susceptible to histamine accumulation.
- Which of these real-world use hold for the sense of histamine this model covers, and on what evidence? provenance
Typical measurements
Recalled without web access and unsourced; every item is a lead to verify.
- Molar mass of histamine free base - 111.15 - g/mol
- Which of these typical measurements hold for the sense of histamine this model covers, and on what evidence? provenance
Failure modes and hazards
Recalled without web access and unsourced; every item is a lead to verify.
- Excess histamine exposure can produce flushing, headache, itching, gastrointestinal symptoms and cardiovascular effects.
- Microbial conversion of histidine to histamine in improperly stored fish can cause scombroid poisoning.
- Histamine already present in food is not reliably eliminated by ordinary cooking.
- Confusing free-base and salt masses produces concentration errors when preparing solutions.
- Which of these failure modes and hazards hold for the sense of histamine this model covers, and on what evidence? provenance
Regional variation
Recalled without web access and unsourced; every item is a lead to verify.
- Food safety limits and sampling requirements for histamine vary by jurisdiction and food category.
- Which of these regional variation hold for the sense of histamine this model covers, and on what evidence? provenance
Neighbouring kinds and how to tell them apart
Recalled without web access and unsourced; every item is a lead to verify.
- Histidine - Histidine is an amino acid with a carboxyl group; its decarboxylation produces histamine.
- Histamine receptor - A receptor is a protein that responds to histamine; histamine is its small-molecule ligand.
- Antihistamine - An antihistamine modifies or blocks histamine receptor activity rather than being histamine itself.
- Histamine-containing food - A food is a mixture whose histamine concentration can vary; histamine is the individual chemical constituent.
- Which of these neighbouring kinds and how to tell them apart hold for the sense of histamine this model covers, and on what evidence? provenance
What the second pass must settle
- Which authoritative identifiers and reference records should anchor histamine free base and link its salts without conflating their material properties?
- What reliable form-specific measurements establish solubility, acid-base behaviour, phase transitions and storage stability, including whether reported boiling values describe meaningful experimental behaviour?
- Which validated methods and sampling controls are appropriate for the intended food, biological and laboratory matrices, and what interference or recovery limitations remain?
- Which current hazard classifications, occupational exposure limits if any, and food criteria apply in the target jurisdictions and to which forms or matrices?
- What evidence supports interpretation of histamine measurements in each biological setting, and which conclusions remain unsupported by a concentration measurement alone?