Pulmonary vascular resistance: molecular mechanisms & dependencies

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.

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

In thirteen patients with severe pulmonary hypertension the decrease in pulmonary vascular resistance was similar with inhaled nitric oxide at 19% and sildenafil at 27% while the combination was more effective than inhaled nitric oxide alone at 32%, sildenafil and the combination increased cardiac index by 17% whereas inhaled nitric oxide did not, inhaled nitric oxide increased whereas sildenafil tended to decrease pulmonary capillary wedge pressure, systemic arterial pressure was similar among groups and did not decrease, and cyclic GMP rose similarly with each agent while the combination raised it synergistically.
Sildenafil → Pulmonary vascular resistance source_derived_draftungraded
Experimental context and source evidence
evidence_span
{"source_cache": "artifacts/sildenafil-research/12021227.abstract.txt", "locator": "Indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "69f5687bcf1bb0fcf9d96eb7fe2f756ccfe3bbdd76af85560110b985245947e0", "start_char": 0, "end_char": 1828, "text_sha256": "69f5687bcf1bb0fcf9d96eb7fe2f756ccfe3bbdd76af85560110b985245947e0"}
experimental_model
Acute haemodynamic study in thirteen consecutive patients referred for transplantation assessment or therapy guidance
exposure
Inhaled nitric oxide at 80 parts per million, oral sildenafil 75 milligrams, and the combination, with serum cyclic GMP measured
limitations
Compares the drug directly against the reference selective pulmonary vasodilator in the same patients and measures the messenger. Thirteen patients and a single dose.
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
Human
plain_language
An oral tablet matched inhaled nitric oxide as a selective lung vasodilator and, unlike it, raised cardiac output.
primary_references
[sil-p12021227] Oral sildenafil is an effective and specific pulmonary vasodilator in patients with pulmonary arterial hypertension: comparison with inhaled nitric oxide. (2002). https://pubmed.ncbi.nlm.nih.gov/12021227/ DOI: 10.1161/01.cir.0000016641.12984.dc
tissue_or_cell_type
Pulmonary circulation
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 535–546
AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Acute haemodynamic study in thirteen consecutive patients referred for transplantation assessment or therapy guidance · source_derived_draft · unverified_draft
### sil-as-selective-as-inhaled-no In thirteen patients with severe pulmonary hypertension the decrease in pulmonary vascular resistance was similar with inhaled nitric oxide at 19% and sildenafil at 27% while the combination was more effective than inhaled nitric oxide alone at 32%, sildenafil and the combination increased cardiac index by 17% whereas inhaled nitric oxide did not, inhaled nitric oxide increased whereas sildenafil tended to decrease pulmonary capillary wedge pressure, systemic arterial pressure was similar among groups and did not decrease, and cyclic GMP rose similarly with each agent while the combination raised it synergistically. 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: An oral tablet matched inhaled nitric oxide as a selective lung vasodilator and, unlike it, raised cardiac output. organism: Human tissue_or_cell_type: Pulmonary circulation experimental_model: Acute haemodynamic study in thirteen consecutive patients referred for transplantation assessment or therapy guidance limitations: Compares the drug directly against the reference selective pulmonary vasodilator in the same patients and measures the messenger. Thirteen patients and a single dose. exposure: Inhaled nitric oxide at 80 parts per million, oral sildenafil 75 milligrams, and the combination, with serum cyclic GMP measured evidence_span: {"source_cache": "artifacts/sildenafil-research/12021227.abstract.txt", "locator": "Indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "69f5687bcf1bb0fcf9d96eb7fe2f756ccfe3bbdd76af85560110b985245947e0", "start_char": 0, "end_char": 1828, "text_sha256": "69f5687bcf1bb0fcf9d96eb7fe2f756ccfe3bbdd76af85560110b985245947e0"} [sil-p12021227] Oral sildenafil is an effective and specific pulmonary vasodilator in patients with pulmonary arterial hypertension: comparison with inhaled nitric oxide. (2002). https://pubmed.ncbi.nlm.nih.gov/12021227/ DOI: 10.1161/01.cir.0000016641.12984.dc
Complete structured claim and evidence
Combined citrulline and BH4 improved pulmonary vascular resistance more than either alone in hypoxic piglets.
L-Citrulline plus tetrahydrobiopterin, study-specific combination → Pulmonary vascular resistance source_derived_draftungraded
Experimental context and source evidence
evidence_span
{"source_cache": "artifacts/citrulline-research/32073878.abstract.txt", "locator": "Primary indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "3362b0aae303b9c2e54cfa8a291e4d993ab4496d26cf11a1dba96c27c4c3fb7f", "start_char": 0, "end_char": 1850, "text_sha256": "3362b0aae303b9c2e54cfa8a291e4d993ab4496d26cf11a1dba96c27c4c3fb7f"}
experimental_model
Controlled neonatal hypoxia and combination-treatment experiment
exposure
L-citrulline, sapropterin, or both during days 3-10 of hypoxia
limitations
Animal combination evidence; does not establish neonatal clinical dosing or treatment benefit in humans.
nutrient_topic
Citrulline research collection; topical membership is not evidence of a direct dietary effect. · L-Citrulline
organism
Newborn pig
plain_language
Both substrate supply and cofactor support mattered in this animal model.
primary_references
[citrulline-p32073878] Combined l-citrulline and tetrahydrobiopterin therapy improves NO signaling and ameliorates chronic hypoxia-induced pulmonary hypertension in newborn pigs. (2020). https://pubmed.ncbi.nlm.nih.gov/32073878/ DOI: 10.1152/ajplung.00280.2019
tissue_or_cell_type
Pulmonary arteries and hemodynamics
Citrulline: arginine recycling, nitrogen disposal and nutrient connections (2026-09-17) · lines 814–825
AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Controlled neonatal hypoxia and combination-treatment experiment · source_derived_draft · unverified_draft
### citrulline-pig-combination-pvr Combined citrulline and BH4 improved pulmonary vascular resistance more than either alone in hypoxic piglets. Condition category: normal nutrient_topic: Citrulline research collection; topical membership is not evidence of a direct dietary effect. plain_language: Both substrate supply and cofactor support mattered in this animal model. organism: Newborn pig tissue_or_cell_type: Pulmonary arteries and hemodynamics experimental_model: Controlled neonatal hypoxia and combination-treatment experiment limitations: Animal combination evidence; does not establish neonatal clinical dosing or treatment benefit in humans. exposure: L-citrulline, sapropterin, or both during days 3-10 of hypoxia evidence_span: {"source_cache": "artifacts/citrulline-research/32073878.abstract.txt", "locator": "Primary indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "3362b0aae303b9c2e54cfa8a291e4d993ab4496d26cf11a1dba96c27c4c3fb7f", "start_char": 0, "end_char": 1850, "text_sha256": "3362b0aae303b9c2e54cfa8a291e4d993ab4496d26cf11a1dba96c27c4c3fb7f"} [citrulline-p32073878] Combined l-citrulline and tetrahydrobiopterin therapy improves NO signaling and ameliorates chronic hypoxia-induced pulmonary hypertension in newborn pigs. (2020). https://pubmed.ncbi.nlm.nih.gov/32073878/ DOI: 10.1152/ajplung.00280.2019
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

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

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.

Pulmonary vascular resistance