Component

Phosphodiesterase 9A

Phosphodiesterase 9A. Species, exposure and limitations are retained in each linked claim.

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

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. The newly cloned phosphodiesterase PDE9A1 is highly specific for cyclic GMP with a Michaelis constant of approximately 0.07 micromolar, the lowest yet reported for a phosphodiesterase and at least 40 to 170 times lower than that of PDE5 and PDE6 respectively, it shows highest messenger RNA expression in kidney with lower levels in liver, lung and brain, and when expressed in COS-7 cells its activity was not inhibited well by either the nonselective inhibitor 3-isobutyl-1-methylxanthine or the new selective PDE5 inhibitor sildenafil, while the PDE1 and PDE5 inhibitor SCH51866 inhibited it with a half-maximal concentration of 1.55 micromolar.

    Sildenafil → Phosphodiesterase 9A source_derived_draftungraded
    Experimental context and source evidence
    evidence_span
    {"source_cache": "artifacts/sildenafil-research/9624145.abstract.txt", "locator": "Indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "ea6afcfbb102bf5a407894b06969c9fe245261fa8a1fea8fb92b201d8b24ace2", "start_char": 0, "end_char": 1265, "text_sha256": "ea6afcfbb102bf5a407894b06969c9fe245261fa8a1fea8fb92b201d8b24ace2"}
    experimental_model
    Cloning, expression and kinetic characterisation of a newly identified cyclic nucleotide phosphodiesterase family
    exposure
    Recombinant PDE9A1 against 3-isobutyl-1-methylxanthine, sildenafil and SCH51866
    limitations
    A cloning and characterisation report. The expression survey is messenger RNA rather than protein, and the enzyme is heterologously expressed.
    nutrient_topic
    Sildenafil research collection; topical membership is not evidence of a direct clinical effect, and the drug is recorded separately from its N-desmethyl metabolite and its target enzyme from the homologous retinal PDE6. · Sildenafil
    organism
    Mouse
    plain_language
    There is another enzyme that destroys the same messenger even more avidly, and this drug does not touch it.
    primary_references
    [sil-p9624145] Identification and characterization of a novel family of cyclic nucleotide phosphodiesterases. (1998). https://pubmed.ncbi.nlm.nih.gov/9624145/ DOI: 10.1074/jbc.273.25.15553
    tissue_or_cell_type
    Kidney, liver, lung and brain messenger RNA

    Sildenafil: the enzyme it occupies instead of the substrate, why it cannot start a signal it can only preserve, the organic nitrate interaction that follows from that, the homologous retinal enzyme ten-fold away, and the pulmonary circulation where the same mechanism became a second indication (2026-09-22) · lines 236–247

    AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Cloning, expression and kinetic characterisation of a newly identified cyclic nucleotide phosphodiesterase family · source_derived_draft · unverified_draft

    ### sil-another-cgmp-enzyme-it-misses The newly cloned phosphodiesterase PDE9A1 is highly specific for cyclic GMP with a Michaelis constant of approximately 0.07 micromolar, the lowest yet reported for a phosphodiesterase and at least 40 to 170 times lower than that of PDE5 and PDE6 respectively, it shows highest messenger RNA expression in kidney with lower levels in liver, lung and brain, and when expressed in COS-7 cells its activity was not inhibited well by either the nonselective inhibitor 3-isobutyl-1-methylxanthine or the new selective PDE5 inhibitor sildenafil, while the PDE1 and PDE5 inhibitor SCH51866 inhibited it with a half-maximal concentration of 1.55 micromolar. Condition category: normal nutrient_topic: Sildenafil research collection; topical membership is not evidence of a direct clinical effect, and the drug is recorded separately from its N-desmethyl metabolite and its target enzyme from the homologous retinal PDE6. plain_language: There is another enzyme that destroys the same messenger even more avidly, and this drug does not touch it. organism: Mouse tissue_or_cell_type: Kidney, liver, lung and brain messenger RNA experimental_model: Cloning, expression and kinetic characterisation of a newly identified cyclic nucleotide phosphodiesterase family limitations: A cloning and characterisation report. The expression survey is messenger RNA rather than protein, and the enzyme is heterologously expressed. exposure: Recombinant PDE9A1 against 3-isobutyl-1-methylxanthine, sildenafil and SCH51866 evidence_span: {"source_cache": "artifacts/sildenafil-research/9624145.abstract.txt", "locator": "Indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "ea6afcfbb102bf5a407894b06969c9fe245261fa8a1fea8fb92b201d8b24ace2", "start_char": 0, "end_char": 1265, "text_sha256": "ea6afcfbb102bf5a407894b06969c9fe245261fa8a1fea8fb92b201d8b24ace2"} [sil-p9624145] Identification and characterization of a novel family of cyclic nucleotide phosphodiesterases. (1998). https://pubmed.ncbi.nlm.nih.gov/9624145/ DOI: 10.1074/jbc.273.25.15553
    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