Component

Reduced ascorbate inside the chromaffin granule

Reduced ascorbate inside the chromaffin granule. Species, exposure and limitations are retained in each linked claim.

2 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 acts on it

  1. Incubation with tyramine produced a time-dependent decrease in reduced intragranular ascorbate proportional to extragranular tyramine concentration over 50 microM to 2 mM.

    Dopamine beta-hydroxylase catalytic turnover → Reduced ascorbate inside the chromaffin granule source_derived_draftungraded
    Experimental context and source evidence
    availability_state
    nutrient_deficiency Imported condition classification; unverified.
    evidence_span
    {"source_cache": "artifacts/cold-research/3949732.abstract.txt", "locator": "Indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "9db1233389aeb375adfd655ea04f39ccb05e22773f367aaa1292bb21698242e1", "start_char": 0, "end_char": 2000, "text_sha256": "9db1233389aeb375adfd655ea04f39ccb05e22773f367aaa1292bb21698242e1"}
    experimental_model
    Intact bovine chromaffin granules undergoing dopamine beta-hydroxylase turnover with labelled ascorbate
    exposure
    Tyramine- or dopamine-stimulated turnover with extragranular ascorbate
    limitations
    An in vitro demonstration in intact granules. Ascorbate itself does not cross the membrane, which is precisely why a shuttle is required.
    nutrient_topic
    Cold water immersion research collection; topical membership is not evidence of a direct clinical effect, and a therapeutic exposure is not a dietary intake. · Cold water immersion
    organism
    Bovine
    plain_language
    Every molecule of noradrenaline made costs the vesicle a molecule of vitamin C.
    primary_references
    [cold-p3949732] Evidence for an ascorbate shuttle for the transfer of reducing equivalents across chromaffin granule membranes. (1986). https://pubmed.ncbi.nlm.nih.gov/3949732/ DOI: 10.1016/s0021-9258(17)35819-2
    tissue_or_cell_type
    Adrenal chromaffin granules
    trigger_kind
    nutrient_deficiency Imported condition classification; unverified.

    Cold water immersion: cold sensing, heat production, the catecholamine axis and what repeated exposure changes (2026-09-19) · lines 611–622

    AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Intact bovine chromaffin granules undergoing dopamine beta-hydroxylase turnover with labelled ascorbate · source_derived_draft · unverified_draft

    ### cold-ascorbate-depletion-in-granule Incubation with tyramine produced a time-dependent decrease in reduced intragranular ascorbate proportional to extragranular tyramine concentration over 50 microM to 2 mM. Condition category: nutrient_deficiency nutrient_topic: Cold water immersion research collection; topical membership is not evidence of a direct clinical effect, and a therapeutic exposure is not a dietary intake. plain_language: Every molecule of noradrenaline made costs the vesicle a molecule of vitamin C. organism: Bovine tissue_or_cell_type: Adrenal chromaffin granules experimental_model: Intact bovine chromaffin granules undergoing dopamine beta-hydroxylase turnover with labelled ascorbate limitations: An in vitro demonstration in intact granules. Ascorbate itself does not cross the membrane, which is precisely why a shuttle is required. exposure: Tyramine- or dopamine-stimulated turnover with extragranular ascorbate evidence_span: {"source_cache": "artifacts/cold-research/3949732.abstract.txt", "locator": "Indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "9db1233389aeb375adfd655ea04f39ccb05e22773f367aaa1292bb21698242e1", "start_char": 0, "end_char": 2000, "text_sha256": "9db1233389aeb375adfd655ea04f39ccb05e22773f367aaa1292bb21698242e1"} [cold-p3949732] Evidence for an ascorbate shuttle for the transfer of reducing equivalents across chromaffin granule membranes. (1986). https://pubmed.ncbi.nlm.nih.gov/3949732/ DOI: 10.1016/s0021-9258(17)35819-2
    Complete structured claim and evidence

  2. Chromaffin granules must shuttle reducing equivalents inward to re-reduce ascorbate oxidised during noradrenaline synthesis: tyramine-driven turnover oxidised intragranular ascorbate with a stoichiometry of octopamine synthesised to ascorbate oxidised near unity, 95% inhibited by the enzyme inhibitor disulfiram, and abolished or reversed by extragranular ascorbate, while labelled ascorbate showed no transmembrane transport of the vitamin itself.

    Cytosolic ascorbate pool → Reduced ascorbate inside the chromaffin granule source_derived_draftungraded
    Experimental context and source evidence
    evidence_span
    {"source_cache": "artifacts/cold-research/3949732.abstract.txt", "locator": "Indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "9db1233389aeb375adfd655ea04f39ccb05e22773f367aaa1292bb21698242e1", "start_char": 0, "end_char": 2000, "text_sha256": "9db1233389aeb375adfd655ea04f39ccb05e22773f367aaa1292bb21698242e1"}
    experimental_model
    Intact bovine chromaffin granules undergoing dopamine beta-hydroxylase turnover with labelled ascorbate
    exposure
    Tyramine- or dopamine-stimulated turnover with extragranular ascorbate
    limitations
    An in vitro demonstration in intact granules. Ascorbate itself does not cross the membrane, which is precisely why a shuttle is required.
    nutrient_topic
    Cold water immersion research collection; topical membership is not evidence of a direct clinical effect, and a therapeutic exposure is not a dietary intake. · Cold water immersion
    organism
    Bovine
    plain_language
    The vitamin cannot cross into the vesicle, so the cell passes electrons across the membrane instead.
    primary_references
    [cold-p3949732] Evidence for an ascorbate shuttle for the transfer of reducing equivalents across chromaffin granule membranes. (1986). https://pubmed.ncbi.nlm.nih.gov/3949732/ DOI: 10.1016/s0021-9258(17)35819-2
    tissue_or_cell_type
    Adrenal chromaffin granules

    Cold water immersion: cold sensing, heat production, the catecholamine axis and what repeated exposure changes (2026-09-19) · lines 598–609

    AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Intact bovine chromaffin granules undergoing dopamine beta-hydroxylase turnover with labelled ascorbate · source_derived_draft · unverified_draft

    ### cold-ascorbate-shuttle Chromaffin granules must shuttle reducing equivalents inward to re-reduce ascorbate oxidised during noradrenaline synthesis: tyramine-driven turnover oxidised intragranular ascorbate with a stoichiometry of octopamine synthesised to ascorbate oxidised near unity, 95% inhibited by the enzyme inhibitor disulfiram, and abolished or reversed by extragranular ascorbate, while labelled ascorbate showed no transmembrane transport of the vitamin itself. Condition category: normal nutrient_topic: Cold water immersion research collection; topical membership is not evidence of a direct clinical effect, and a therapeutic exposure is not a dietary intake. plain_language: The vitamin cannot cross into the vesicle, so the cell passes electrons across the membrane instead. organism: Bovine tissue_or_cell_type: Adrenal chromaffin granules experimental_model: Intact bovine chromaffin granules undergoing dopamine beta-hydroxylase turnover with labelled ascorbate limitations: An in vitro demonstration in intact granules. Ascorbate itself does not cross the membrane, which is precisely why a shuttle is required. exposure: Tyramine- or dopamine-stimulated turnover with extragranular ascorbate evidence_span: {"source_cache": "artifacts/cold-research/3949732.abstract.txt", "locator": "Indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "9db1233389aeb375adfd655ea04f39ccb05e22773f367aaa1292bb21698242e1", "start_char": 0, "end_char": 2000, "text_sha256": "9db1233389aeb375adfd655ea04f39ccb05e22773f367aaa1292bb21698242e1"} [cold-p3949732] Evidence for an ascorbate shuttle for the transfer of reducing equivalents across chromaffin granule membranes. (1986). https://pubmed.ncbi.nlm.nih.gov/3949732/ DOI: 10.1016/s0021-9258(17)35819-2
    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.

    Evidence, AI assistance and curation standards