Gaseous Hormones

Main thing

Gaseous hormones in humans are unique signaling molecules that exist as gases and play critical roles in various bodily functions. Unlike traditional hormones, these gaseous molecules can freely diffuse across cell membranes, enabling them to quickly reach and affect target cells. The most notable gaseous signaling molecules in humans include nitric oxide (NO), carbon monoxide (CO), and hydrogen sulfide (H2S). Each of these gases is produced in specific cells and has distinct functions within the body.

• Nitric Oxide (NO): Produced by endothelial cells lining the blood vessels, NO plays a vital role in regulating blood pressure by signaling blood vessels to relax and dilate. It also has functions in the immune system and neurotransmission.

• Carbon Monoxide (CO): Generated in small amounts during the breakdown of heme by heme oxygenase enzymes, CO has anti-inflammatory effects and is involved in neurotransmission. Despite its toxicity at high concentrations, at physiological levels, it plays protective roles in the cardiovascular system.

• Hydrogen Sulfide (H2S): Produced in various tissues, including the brain, blood vessels, and heart, H2S is involved in regulating blood pressure, inflammatory responses, and may have neuroprotective effects.

Example: Nitric oxide regulates blood pressure by causing blood vessels to relax and widen.

Terms

• Nitric Oxide (NO) - A gaseous signaling molecule in humans that helps control blood pressure, fights infections, and communicates between nerve cells. Example: NO is produced in the endothelial cells lining blood vessels, causing them to dilate and lower blood pressure.

• Carbon Monoxide (CO) - A gaseous molecule produced in small amounts in the human body, playing roles in neurotransmission and as an anti-inflammatory agent. Example: CO is generated as a byproduct of heme breakdown and has protective roles in reducing inflammation.

• Signaling Molecule - A chemical that transmits information from one cell to another, allowing cells to communicate. Example: Hormones, neurotransmitters, and gaseous signaling molecules like NO and CO.

• Diffusion - The process by which molecules spread from areas of high concentration to areas of low concentration. Example: Gaseous hormones diffuse directly across cell membranes to reach their target cells.

An analogy

Imagine a gaseous hormone as a whisper that quickly spreads through a crowded room. Just as a whisper can move freely among people, gaseous hormones diffuse effortlessly across cell membranes, delivering messages directly to nearby cells without needing a specific delivery system.

A main misconception

Many people think all hormones are produced in specific glands and travel through the bloodstream to act on distant organs. However, gaseous hormones like NO and CO are produced locally and act directly on nearby cells without traveling through the bloodstream.
Example: Nitric oxide produced in blood vessel walls directly causes the vessels to dilate, affecting blood flow locally rather than systemically.

The history

1. 1987: Nitric oxide (NO) is identified as a unique signaling molecule in mammals, challenging the traditional view of hormones.

2. 1992: The Nobel Prize in Physiology or Medicine is awarded for discoveries concerning NO as a signaling molecule in the cardiovascular system.

3. 2000s: Research expands on the role of gaseous signaling molecules, including carbon monoxide (CO) and hydrogen sulfide (H2S), in various physiological processes.

"The discovery of nitric oxide and its function is an important proof that scientific breakthroughs often challenge old truths." - Louis J. Ignarro, Nobel Laureate, famous for his work on nitric oxide as a signaling molecule.

Three cases how to use it right now (Revised)

1. Exercise for NO Production: Regular physical activity can enhance the body's ability to produce nitric oxide, which in turn can help maintain healthy blood pressure levels and improve overall cardiovascular health. Engaging in exercises, especially aerobic activities, can stimulate the production of NO, aiding in the dilation of blood vessels and improving blood flow.

2. Dietary Choices for H2S and CO: Consuming foods rich in sulfur (such as garlic, onions, and cruciferous vegetables) can boost the body's production of hydrogen sulfide (H2S), which has been linked to protective cardiovascular effects. Similarly, while it's not advisable to seek out sources of carbon monoxide due to its toxicity at high levels, understanding the body's use of CO at physiological levels can lead to research into therapeutic uses, such as controlled exposure to promote healing and reduce inflammation in medical settings.

3. Monitoring Environmental Exposure: Being aware of the sources of gaseous molecules like NO, CO, and H2S in the environment can help individuals minimize harmful exposure. For example, excessive inhalation of CO from pollution or smoke can be detrimental to health, overriding the body's use of endogenously produced CO. Similarly, understanding that NO and H2S can be beneficial in controlled amounts encourages a balanced approach to managing exposure to these gases, whether through environmental sources or therapeutic applications.

These cases illustrate how an understanding of gaseous hormones and their functions can influence everyday decisions and health practices, from exercise and diet to environmental awareness.

Interesting facts

• Nitric oxide was named "Molecule of the Year" in 1992 by Science magazine.

• Human bodies produce carbon monoxide in small amounts as part of normal metabolism.

• Nitric oxide plays a crucial role in the immune system, helping to kill bacteria and fight off infections.

• The discovery of gaseous hormones challenged the traditional definition of hormones, expanding it to include gases.

• Carbon monoxide (CO) is a silent killer; it's colorless, odorless, and can be deadly. It binds with hemoglobin in the blood more effectively than oxygen, preventing vital organs from receiving the oxygen they need. This can lead to serious health issues or death, even with exposure to relatively low levels. Despite its dangers, CO is produced by everyday activities, such as using gas stoves or driving cars.