ScienceDaily (July 31, 2012) ? Cold feet -- those chilly appendages that plague many people in the winter and an unlucky few all year round -- can be the bane of existence for singles and couples alike. In a new study, scientists led by Selvi C. Jeyaraj of the Research Institute at Nationwide Children's Hospital have identified a biological mechanism that may be responsible for icy extremities: an interaction between a series of molecules and receptors on smooth muscle cells that line the skin's tiny blood vessels.
The new research, along with an accompanying editorial by Martin C. Michel of Johannes Gutenberg University in Mainz, Germany, and Paul A. Insel of the University of California at San Diego, suggest new contributors to this near-universal problem and potential targets to treat more serious problems that affect blood vessels in the cold, such as in Raynaud's disease.
The article appears in the American Journal of Physiology -- Cell Physiology.
Methodology
Jeyaraj and her colleagues studied smooth muscle cells derived from tiny blood vessels harvested from human skin biopsies and similar cells from mouse tail arteries. These cells contain receptors known as ?2C-AR, which cause constriction in their associated blood vessels and shut off blood flow under chilly conditions to conserve heat. The scientists also worked with different cells, called HEK cells, that do not normally express ?2C-AR but that can be modified to do so. Also studied were cells taken from tail arteries of mice genetically altered to no longer express a protein called Rap1A, which the authors hypothesized would interact with ?2C-AR.
Results
The researchers found that when they dosed cells that expressed ?2C-AR with chemicals that activate Rap1A, either directly or through means that involve another protein called Epac, the cells drew from pools of ?2C-AR near the cell's nucleus and moved these receptors to the cell surface. The series of events involved rearrangment of the cell's internal "skeleton," fibers that determine its shape and can transport items from one area of a cell to another.
Importance of the Findings and What Part of Cell Physiology Gets 'The Rap' Authors of the study and the accompanying editorial suggest that the series of events and biological interactions they identified could be responsible for the mechanism the body uses to limit blood supply to the skin in cold temperatures, which conserves more blood flow -- and hence, warmth -- for the body's internal organs. The findings may provide clues to where dysfunction occurs in disorders in which blood flow is erroneously cut off, such as Raynaud's disease. In this condition, sufferers lose circulation to the fingers, toes, and occasionally other areas when the body overreacts to cold temperatures. Raynaud's can sometimes be serious, leading to atrophy of skin and muscle, ulceration and rarely to ischemic gangrene. On a lighter note, the results also provide a possible explanation for the age-old problem of cold feet.
"Thus, if your partner complains again about your cold feet," the editorial authors write, "you have some new excuses: 'It's Epac's fault!' or 'Rap1A should get the rap!'"
Study Team In addition to Selvi C. Jeyaraj, the study team also includes Nicholas T. Unger and N. Paul El-Dahdah of The Research Institute at Nationwide Children's Hospital, Ali H. Eid of Qatar University, Srabani Mitra of Ohio State University, Lawrence A. Quilliam of Indiana University School of Medicine, Nicholas A. Flavahan of Johns Hopkins University, and Maqsood A. Chotani of The Research Institute at Nationwide Children's Hospital and Ohio State University.
Share this story on Facebook, Twitter, and Google:
Other social bookmarking and sharing tools:
Story Source:
The above story is reprinted from materials provided by American Physiological Society (APS).
Note: Materials may be edited for content and length. For further information, please contact the source cited above.
Journal Reference:
- S. C. Jeyaraj, N. T. Unger, A. H. Eid, S. Mitra, N. P. El-Dahdah, L. A. Quilliam, N. A. Flavahan, M. A. Chotani. Cyclic AMP-Rap1A Signaling Activates RhoA to Induce ?2C-Adrenoceptor Translocation to the Cell Surface of Microvascular Smooth Muscle Cells. AJP: Cell Physiology, 2012; DOI: 10.1152/ajpcell.00461.2011
Note: If no author is given, the source is cited instead.
Disclaimer: This article is not intended to provide medical advice, diagnosis or treatment. Views expressed here do not necessarily reflect those of ScienceDaily or its staff.
Source: http://feeds.sciencedaily.com/~r/sciencedaily/~3/srzAll3h9fs/120731151711.htm
duggars peter facinelli bobby rush supreme court justices 19 kids and counting danny o brien alicia silverstone
. Of course, it ended with shivers and purple lips and him claiming he wasn?t cold. I remember those days. Who really wants the fun to end?
Both are design-driven innovative facilities that provide the best and latest programmes and equipments for looking good, feeling good, and having a good time in the pursuit of total wellness.
While we reported a few weeks ago that Goddard was re-writing the ending of World War Z based on an idea by Damon Lindelof, Goddard clarified things a bit:
Here?s the full interview broken down by time index.
60-Second Science |
More Science
About the author 
What do you get when a ?gearhead? sales and marketing pro moves to the Truckee Meadows from the ?Motor City? to head up the Reno-Sparks Convention & Visitors Authority? A customized 1951 Willys Jeep four-wheel drive Station Wagon that will represent the region ? and promote the wide variety of attractions, festivals, activities and events available in the Reno/Sparks/North Lake Tahoe area ? to crowds at conventions, tradeshows and high profile events in Northern Nevada, California and further afield.
?Everybody loves checking out a classic car? especially one that is beautifully hand-lettered and pinstriped, upholstered in Pendleton Indian blanket material and topped off with a hand-made, aluminum roof rack system packed with everything from skis and snowshoes to a kayak, golf clubs, fishing rods and a slalom water ski,? according to Christopher Baum, President and CEO of the RSCVA and creator of the vehicle. ?It?s the perfect conversation starter to attract attention and help educate prospective visitors on the incredible diversity of things to do throughout Northern Nevada!?
The RSCVA?s new promotional vehicle is tentatively scheduled to make appearances, subject to commitments outside the Reno/Sparks/North Lake Tahoe region, at the following events: Reno-Tahoe Open, Hot August Nights, Toyota Silver State Showdown, Best in the West Nugget Rib Cookoff, The Great Reno Balloon Race, National Championship Air Races, Street Vibrations Fall Rally, Eldorado Great Italian Festival and the Sparks Hometowne Christmas Parade.
In his address to the Knesset plenum in the final winter session on Wednesday, 6 Menachem Av 5772, MK (Yahadut HaTorah) Rav Uri Maklev spoke of the late posek hador, Maran Rav Elyashiv ZT?L, speaking of the hundreds of thousands of people who attended the levaya and escorted the aaron to Har Menuchos. He explained this showed the level of ?kovod hatorah? seeking to explain to his fellow parliamentarians that ?the rav never addressed Knesset but words were heard. His rulings and his hashkafa were the subject of addresses and on more than a few occasions I was asked to describe the rav that merited being the gadol hador. I was also asked how so many people assembled in the short time between his petira and the levaya, hundreds of thousands from around the country to take part until late into the night. What brought them??
Subscribe to RSS Feed For This Article
