Vasodilator Definition and Most Potent Vasodilators: CO2 and NO

Effects of overbreathing and coughing on brain oxygen levels Vasodilator (definition) is a factor that causes an increase in the diameter of blood vessels. This mainly relates to dilation of small arteries and arterioles since they create the main resistance to the systemic blood flow in the human body (about 70%). A vasodilator can be:
1) a chemical substance
2) or various stimuli, such as reactive hyperemia (in skin and muscles), exercise hyperemia (muscle), whole body heating (skin) and mental stress (muscle).

Since over 90% of people breathe much more than the medical norm (see the Homepage for clinical studies), the main problem with vasodilators relate to ineffective breathing.

Effects of
vasodilators: dilation of blood vessels The most common application of vasodilators is to reduce blood pressure in people with hypertension and also treat conditions with poor circulation, such as chilblains and Raynaud's syndrome (poor circulation in hands and feet). Insufficient and worsening perfusion of vital organs is a clinical feature in progressing cancer, diabetes, arthritis, hypothyroidism, CFS, and many other conditions.

The blood vessels are expanded either by relaxing the smooth muscles of the vessel walls (as occurs with CO2, nitric oxide, nitrates and calcium antagonists) or by changing nerve signals that control the tone of the blood vessels (as occurs with alpha blockers).

CO2 and NO (nitric oxide): most potent natural vasodilators (from food)

"... Carbon dioxide, a most potent cerebral vasodilator, ..." Djurberg HG, Tjan GT, Al Moutaery KR, Enhanced catheter propagation with hypercapnia during superselective cerebral cauterization, Neuroradiology, 1998 Jul; 40(7): 466-8.

Man runing on a beach In the right conditions, the human body can take care of normal blood flow to all organs and tissues due to the two most potent vasodilators naturally present in the blood and other cells due to food sources. These natural vasodilators are CO2 (carbon dioxide) and NO (nitric oxide).

Carbohydrates and fats are naturally present in food sources and contain carbon atoms that are oxidized to CO2. Nitric oxide is produced in various parts of the human body from arginine, an amino acid present in various food sources, especially meat, fish, and nuts. The action of nitroglycerine and many other drugs are based on release of nitric oxide. Since sinuses are important sources of nasal NO, nose breathing and the normal unconscious breathing pattern (relatively sharp, but small and short inhalations with long and slow exhalations) are crucial for the utilization of nasal NO.

Mouth breathing (including during physical exercise) prevents absorption of nasal NO and also reduces arterial CO2 levels causing problems with most important vasodilators. Carbon dioxide losses occur due to hyperventilation which is very common in the sick and even "normal" modern subjects at rest (see links to medical studies below).

This YouTube video "Vasodilator and vasodilation" explains effects of the most potent vasodilator, carbon dioxide, on perfusion.

References: Vasodilator and Most Potent Vasodilators.

Reference pages: Breathing norms and medical facts:
- Breathing norms: Parameters, graph, and description of the normal breathing pattern
- 6 breathing myths: Myths and superstitions about breathing and body oxygenation (prevalence: over 90%)
- Hyperventilation: Definitions of hyperventilation: their advantages and weak points
- Hyperventilation syndrome: Western scientific evidence about prevalence of chronic hyperventilation in patients with chronic conditions (37 medical studies)
- Normal minute ventilation: Small and slow breathing at rest is enjoyed by healthy subjects (14 studies)
- Hyperventilation prevalence: Present in over 90% of normal people (24 medical studies)
- HV and hypoxia: How and why deep breathing reduces oxygenation of cells and tissues of all vital organs
- Body-oxygen test (CP test) : How to measure your own breathing and body oxygenation (two in one) using a simple DIY test
- Body oxygen in healthy: Results for the body-oxygen test for healthy people (27 medical studies)
- Body oxygen in sick : Results for the body-oxygen test for sick people (14 medical studies)
- Buteyko Table of Health Zones: Clinical description and ranges for breathing zones: from the critically ill (severely sick) up to super healthy people with maximum possible body oxygenation
- Morning hyperventilation: Why people feel worse and critically ill people are most likely to die during early morning hours

References: pages about CO2 effect:
- Vasodilation: CO2 expands arteries and arterioles facilitating perfusion (or blood supply) to all vital organs
- The Bohr effect: How and why oxygen is released by red blood cells in tissues
- Cell oxygen levels: How alveolar CO2 influences oxygen transport
- Oxygen transport: O2 transport is controlled by vasoconstriction-vasodilation and the Bohr effects, both of which rely on CO2
- Free radical generation: Reactive oxygen species are produced within cells due to anaerobic cell respiration caused by cell hypoxia
- Inflammatory response: Chronic inflammation in fueled by the hypoxia-inducible factor 1, while normal breathing reduces and eliminates inflammation
- Nerve stabilization: People remain calm due to calmative or sedative effects of carbon dioxide in neurons or nerve cells
- Muscle relaxation: Relaxation of muscle cells is normal at high CO2, while hypocapnia causes muscular tension, poor posture and, sometimes, aggression and violence
- Bronchodilation: Dilation of airways (bronchi and bronchioles) is caused by carbon dioxide, and their constriction by hypocapnia (low CO2)
- Blood pH: Regulation of blood pH due to breathing and regulation of other bodily fluids
- CO2: lung damage: Elevated carbon dioxide prevents lung injury and promotes healing of lung tissues
- CO2: Topical carbon dioxide can heal skin and tissues
- Synthesis of glutamine in the brain, CO2 fixation, and other chemical reactions
- Deep breathing myth: Ignorant and naive people promote the idea that deep breathing and breathing more air at rest is beneficial for health
- Breathing control: How is our breathing regulated? Why hypocapnia makes breathing uneven, irregular and erratic.