UVR relaxes blood vessels
 

Here comes the sun – How vitamin D relaxes blood vessels
17 January 2014 Veterinärmedizinische Universität Wien

It’s not just your mood that the dark months of winter can influence. Low levels of sunlight also mean lower levels of vitamin D in the body. Vitamin D deficiency can trigger a range of diseases but until recently little was known about the exact biological mechanisms behind this. A research team at the University of Veterinary Medicine, Vienna has now decrypted one of these unknown molecular mechanisms. Vitamin D regulates the elasticity of blood vessels and thus also affects blood pressure amplitude. The results were published earlier this year in the journal Molecular Endocrinology.

UV-B radiation in sunlight is the most important factor for the production of vitamin D, and that is why many people suffer from low levels of vitamin D during the winter months. Although certain foods do contain vitamin D, it is not usually possible to get an adequate supply of the vitamin from food. Many clinical studies have indicated that low vitamin D levels are related to cardiovascular disease such as high blood pressure, but also other diseases such as diabetes mellitus, autoimmune diseases and even cancer. However, the underlying molecular mechanisms were unclear.

Vitamin D deficiency leads to stiffening of the blood vessels

The two primary authors, molecular biologist Olena Andrukhova and medical doctor Svetlana Slavic, of the Institute of Physiology, Pathophysiology and Biophysics at the Vetmeduni Vienna, found that prolonged vitamin D deficiency can stiffen blood vessels. Examining the aorta, an elastic blood vessel that expands with each pulse of blood and then constricts again, the researchers showed that vitamin D deficiency makes the vessel less flexible. Andrukhova explains in detail: "Vitamin D enhances the production of the enzyme eNOS (endothelial nitric oxide synthase) in the inner layer of blood vessels, the endothelium. This is critical for the regulation of blood pressure. The enzyme produces a molecule called nitric oxide (NO), an important factor for the relaxation of smooth muscles in the blood vessels. When too little NO is formed, the vessels become less flexible. This ultimately leads to higher blood pressure which can give rise to other circulatory diseases. So indirectly, vitamin D controls blood pressure."
Co-author Slavic continues: "Stiffness of the blood vessels generally increases with age. Blood pressure amplitude thus tends to increase with age and leads to structural changes in the aorta. Elasticity deteriorates, and prolonged vitamin D deficiency can accelerate this process."

Simulation of vitamin D deficiency in mice

The scientists worked with genetically modified mice to explore the details of the mechanism. The vitamin D receptors in the animals were changed so that no vitamin D signalling was possible. Vitamin D also regulates the body’s calcium and phosphate balance, so the rodents were given a special diet to ensure that they had enough calcium and phosphorus. The lack of vitamin D was therefore the only deficiency that could have affected the physiology of the animals.
After about a year without vitamin D signalling, the mice had increased blood pressure amplitude. The researchers conducted a series of studies on various tissues from the animals. To understand what lies behind the increased blood pressure amplitude, they focused particularly on the aorta and found decreased expression of eNOS, increased deposition of collagen and fewer elastic fibres. Over time, the blood vessels had become more rigid and less able to adapt flexibly to the volume of blood streaming through them. The consequence was increased blood pressure amplitude and changes in cardiac structure and function. In future studies, the researchers want to examine whether vitamin D affects different cell types in blood vessels in different ways.

Refuelling light for the heart and the circulation

In Europe, it has often been considered to enrich certain foods with vitamin D, as is customary in the United States, for example. However, an external source of vitamin D also carries risks since any excess vitamin D cannot be excreted by the body. When used at very high doses it can lead to calcium deposits in blood vessels, kidneys, lungs and the heart. However, a lack of vitamin D can also have dramatic consequences. Institute board Professor Reinhold Erben states: "It is not that vitamin D deficiency will lead immediately to an increase in blood pressure amplitude or blood pressure, but over the long term it can lead to cardiovascular damage. Vitamin D is the chemical translation of the sun in our bodies and we should stock up on a regular basis, especially in winter. We have to remember that in Central Europe, vitamin D synthesis in the skin is physically impossible from November to February at sea level. Levels of UV-B radiation are just too low. The alternatives are vitamin D supplements or a stay in the mountains." [Note: Or, visit your friendly local indoor tanning salon!]

http://www.alphagalileo.org/ViewItem...CultureCode=en

http://www.vetmeduni.ac.at/en/infose...comes-the-sun/

Re: UVR relaxes blood vessels
 

And lowers BP (Blood Pressure).

Here comes the sun to lower your blood pressure
17 January 2014 Southampton, University of

Exposing skin to sunlight may help to reduce blood pressure and thus cut the risk of heart attack and stroke, a study published in the Journal of Investigative Dermatology suggests.

Research carried out at the Universities of Southampton and Edinburgh shows that sunlight alters levels of the small messenger molecule, nitric oxide (NO) in the skin and blood, reducing blood pressure.

Martin Feelisch, Professor of Experimental Medicine and Integrative Biology at the University of Southampton, comments: "NO along with its breakdown products, known to be abundant in skin, is involved in the regulation of blood pressure. When exposed to sunlight, small amounts of NO are transferred from the skin to the circulation, lowering blood vessel tone; as blood pressure drops, so does the risk of heart attack and stroke."

While limiting sunlight exposure is important to prevent skin cancer, the authors of the study, including Dr Richard Weller of the University of Edinburgh,suggest that minimising exposure may be disadvantageous by increasing the risk of prevalent conditions related to cardiovascular disease.

Cardiovascular disease, often associated with high blood pressure, accounts for 30 per cent of deaths globally each year. Blood pressure and cardiovascular disease are known to vary according to season and latitude, with higher levels observed in winter and in countries further from the equator, where ultraviolet radiation from the sun is lower.

During the study, the skin of 24 healthy individuals was exposed to ultraviolet (UVA) light from tanning lamps for two sessions of 20 minutes each. In one session, the volunteers were exposed to both the UVA rays and the heat of the lamps. In another, the UV rays were blocked so that only the heat of the lamps affected the skin.

The results suggest that UVA exposure dilates blood vessels, significantly lowers blood pressure, and alters NO metabolite levels in the circulation, without changing vitamin D levels. Further experiments indicate that pre-formed stores of NO in the upper skin layers are involved in mediating these effects. The data are consistent with the seasonal variation of blood pressure and cardiovascular risk at temperate latitudes.

Professor Feelisch adds: "These results are significant to the ongoing debate about potential health benefits of sunlight and the role of Vitamin D in this process. It may be an opportune time to reassess the risks and benefits of sunlight for human health and to take a fresh look at current public health advice. Avoiding excess sunlight exposure is critical to prevent skin cancer, but not being exposed to it at all, out of fear or as a result of a certain lifestyle, could increase the risk of cardiovascular disease. Perhaps with the exception of bone health, the effects of oral vitamin D supplementation have been disappointing.

"We believe that NO from the skin is an important, so far overlooked contributor to cardiovascular health. In future studies we intend to test whether the effects hold true in a more chronic setting and identify new nutritional strategies targeted at maximizing the skin's ability to store NO and deliver it to the circulation more efficiently."

http://www.alphagalileo.org/ViewItem...CultureCode=en

Re: UVR relaxes blood vessels
 

And perhaps it is time to consider the benefits of the controlled ultraviolet radiation exposure available at your friendly local indoor tanning salon. Or does that make too much sense.

Re: UVR relaxes blood vessels
 

Getting good coverage.

http://www.today.com/health/ahhh-sun...ure-2D11947404

Hope this statement gets picked up:

"We are concerned that well-meaning advice to reduce the comparatively low numbers of deaths from skin cancer may inadvertently increase the risk of death from far higher prevalent cardiovascular disease and stroke, and goes against epidemiological data showing that sunlight exposure reduces all cause and cardiovascular mortality.”

Re: UVR relaxes blood vessels
 

A good factoid; Fact # 1) 38,000 Americans die each year in car accidents. Fact # 2) 1 out of every 4 car accidents involves the use of a cell phone or other electronic device. So, Fact # 3) 25% (1 out of 4) of 38,000 is 9,500 which is about the same number of people who die each year from melanoma. So based on these statistics and the current concern for the loss of life we should take the following actions immediately :

1) The use of Cell phones for anyone under 18 years old should be banned. (its the least we can do / if we can save just one life...)

2) Cell phones should be regulated by the FDA

3) Cell phones should have warning labels on them.

4) All sellers of cell phones should have to go through mandatory training classes before they are allowed to sell cell phones.

5) All cell phone retailers and distributors should also be regulated and audited on a regular basis by the FDA and State.

I am surprised that our faithful public servants have not already picked up on this opportunity to protect the public from the growing menace of people using cell phones while they drive cars. We could also consider;

Banning cars and people. ;)