Component

Nitrous oxide

N2O; experimental cobalamin/MTR inactivation.

3 recorded relationships. Experimental role, claim status and evidence remain attached to each record.

Read recorded mechanisms Open recursive mind map

How nutrients influence it

Every nutrient with a recorded effect on this component, credited to the nutrient that acted rather than the chapter that recorded it. Open a nutrient to see the findings and the conditions they were measured under.

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 it acts on

  1. All eight patients receiving nitrous oxide/oxygen for 24 hours had megaloblastic marrow and abnormal dU suppression; five unexposed patients had normoblastic marrow and normal assays.

    Nitrous oxide → Bone marrow megaloblastosis source_derived_draftungraded
    Experimental context and source evidence
    availability_state
    machinery_impairment Imported condition classification; unverified.
    cross_nutrient
    B12-dependent folate handling connects to DNA synthesis; linked existing MTR evidence supplies the molecular context.
    experimental_model
    Prospective perioperative study in 22 patients undergoing cardiac bypass surgery.
    exposure
    Nitrous oxide/oxygen for 24 hours, during surgery only, or no nitrous oxide; marrow morphology and deoxyuridine suppression assays.
    limitations
    The clinical experiment did not directly measure intracellular cobalamin oxidation state or prove that serum B12 stores were depleted.
    nutrient_topic
    Vitamin B12 research collection; topical membership is not evidence of a direct dietary effect. · Vitamin B12 (cobalamins)
    organism
    Homo sapiens
    plain_language
    The exposed marrow behaved as though a B12-linked DNA-synthesis step was impaired.
    primary_references
    [b12-amess1978] Megaloblastic haemopoiesis in patients receiving nitrous oxide (1978). https://pubmed.ncbi.nlm.nih.gov/79709/ DOI: 10.1016/s0140-6736(78)92941-0
    tissue_or_cell_type
    Human bone marrow
    trigger_kind
    machinery_impairment Imported condition classification; unverified.

    Vitamin B12: mechanisms, deficiency and nutrient interactions (2026-09-17) · lines 1709–1720

    AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Prospective perioperative study in 22 patients undergoing cardiac bypass surgery. · source_derived_draft · unverified_draft

    ### b12-nitrous-oxide-marrow All eight patients receiving nitrous oxide/oxygen for 24 hours had megaloblastic marrow and abnormal dU suppression; five unexposed patients had normoblastic marrow and normal assays. Condition category: machinery_impairment nutrient_topic: Vitamin B12 research collection; topical membership is not evidence of a direct dietary effect. plain_language: The exposed marrow behaved as though a B12-linked DNA-synthesis step was impaired. organism: Homo sapiens tissue_or_cell_type: Human bone marrow experimental_model: Prospective perioperative study in 22 patients undergoing cardiac bypass surgery. limitations: The clinical experiment did not directly measure intracellular cobalamin oxidation state or prove that serum B12 stores were depleted. exposure: Nitrous oxide/oxygen for 24 hours, during surgery only, or no nitrous oxide; marrow morphology and deoxyuridine suppression assays. cross_nutrient: B12-dependent folate handling connects to DNA synthesis; linked existing MTR evidence supplies the molecular context. [b12-amess1978] Megaloblastic haemopoiesis in patients receiving nitrous oxide (1978). https://pubmed.ncbi.nlm.nih.gov/79709/ DOI: 10.1016/s0140-6736(78)92941-0
    Complete structured claim and evidence

  2. In B12-impaired HeLa nuclei, the fraction of measured nuclear folate present as 5-methyl-THF increased over fourfold, while the THF fraction fell approximately 50%, versus replete controls.

    Nitrous oxide → 5-Methyltetrahydrofolate source_derived_draftungraded
    Experimental context and source evidence
    availability_state
    machinery_impairment Imported condition classification; unverified.
    cross_nutrient
    B12 function controls usable folate.
    experimental_model
    N2O-treated HeLa cells and cblG patient fibroblasts.
    limitations
    Fig. 2 reports percentages of measured folate species, not absolute concentrations; chemical/culture impairment is not a dietary threshold.
    nutrient_topic
    Folate and folic acid research collection; topical membership is not evidence of a direct dietary effect. · Folate (vitamin B9)
    organism
    Homo sapiens
    plain_language
    The nuclear folate mixture shifted toward methylfolate.
    primary_references
    [palmer-2017] Folate rescues vitamin B12 depletion-induced inhibition of nuclear thymidylate biosynthesis and genome instability (2017). https://pubmed.ncbi.nlm.nih.gov/28461497/ DOI: 10.1073/pnas.1619582114
    tissue_or_cell_type
    HeLa nuclear fractions
    trigger_kind
    machinery_impairment Imported condition classification; unverified.

    Folate and folic acid: mechanisms, deficiency and nutrient interactions (2026-09-17) · lines 543–553

    AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · N2O-treated HeLa cells and cblG patient fibroblasts. · source_derived_draft · unverified_draft

    ### folate-methyl-nuclear-methyl-trap In B12-impaired HeLa nuclei, the fraction of measured nuclear folate present as 5-methyl-THF increased over fourfold, while the THF fraction fell approximately 50%, versus replete controls. Condition category: machinery_impairment nutrient_topic: Folate and folic acid research collection; topical membership is not evidence of a direct dietary effect. plain_language: The nuclear folate mixture shifted toward methylfolate. organism: Homo sapiens tissue_or_cell_type: HeLa nuclear fractions experimental_model: N2O-treated HeLa cells and cblG patient fibroblasts. limitations: Fig. 2 reports percentages of measured folate species, not absolute concentrations; chemical/culture impairment is not a dietary threshold. cross_nutrient: B12 function controls usable folate. [palmer-2017] Folate rescues vitamin B12 depletion-induced inhibition of nuclear thymidylate biosynthesis and genome instability (2017). https://pubmed.ncbi.nlm.nih.gov/28461497/ DOI: 10.1073/pnas.1619582114
    Complete structured claim and evidence

Where it participates (unsigned role)

  1. Serum B12 remained normal despite the abnormal marrow dU suppression pattern; three of nine surgery-only nitrous oxide recipients also had abnormal assays at 24 hours.

    Serum cobalamin concentration → Deoxyuridine suppression assay source_derived_draftungraded
    Experimental context and source evidence
    availability_state
    machinery_impairment Imported condition classification; unverified.
    experimental_model
    Prospective perioperative study in 22 patients undergoing cardiac bypass surgery.
    exposure
    Nitrous oxide/oxygen for 24 hours, during surgery only, or no nitrous oxide; marrow morphology and deoxyuridine suppression assays.
    limitations
    The assay is an indirect functional test, not a direct methionine-synthase rate measurement.
    nutrient_topic
    Vitamin B12 research collection; topical membership is not evidence of a direct dietary effect. · Vitamin B12 (cobalamins)
    organism
    Homo sapiens
    plain_language
    A normal amount measured in serum did not establish normal intracellular function under this exposure.
    primary_references
    [b12-amess1978] Megaloblastic haemopoiesis in patients receiving nitrous oxide (1978). https://pubmed.ncbi.nlm.nih.gov/79709/ DOI: 10.1016/s0140-6736(78)92941-0
    tissue_or_cell_type
    Human bone marrow and serum
    trigger_kind
    machinery_impairment Imported condition classification; unverified.

    Vitamin B12: mechanisms, deficiency and nutrient interactions (2026-09-17) · lines 1722–1732

    AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Prospective perioperative study in 22 patients undergoing cardiac bypass surgery. · source_derived_draft · unverified_draft

    ### b12-nitrous-oxide-serum-function-discordance Serum B12 remained normal despite the abnormal marrow dU suppression pattern; three of nine surgery-only nitrous oxide recipients also had abnormal assays at 24 hours. Condition category: machinery_impairment nutrient_topic: Vitamin B12 research collection; topical membership is not evidence of a direct dietary effect. plain_language: A normal amount measured in serum did not establish normal intracellular function under this exposure. organism: Homo sapiens tissue_or_cell_type: Human bone marrow and serum experimental_model: Prospective perioperative study in 22 patients undergoing cardiac bypass surgery. limitations: The assay is an indirect functional test, not a direct methionine-synthase rate measurement. exposure: Nitrous oxide/oxygen for 24 hours, during surgery only, or no nitrous oxide; marrow morphology and deoxyuridine suppression assays. [b12-amess1978] Megaloblastic haemopoiesis in patients receiving nitrous oxide (1978). https://pubmed.ncbi.nlm.nih.gov/79709/ DOI: 10.1016/s0140-6736(78)92941-0
    Complete structured claim and evidence

In the sources

Preserved passages that mention this component, quoted exactly. Open one to read it in context.

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

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