Featured Research

from universities, journals, and other organizations

Calcium Storage, Release Mechanism Revealed

March 13, 1997
University of Maryland at Baltimore
Physiologists have learned that cellular calcium is stored in discrete compartments which empty or fill in response to small changes in sodium concentration.Their findings have implications for hypertension, heart failure and stroke.

Related Articles

Now, for the first time, physiologists at the University of Maryland School of Medicine have booked a ringside seat at the show. Using a new technology that enabled them to visualize the organization of calcium stored deep within intact muscle and brain cells, researchers in the medical school’s Center for Vascular Biology and Hypertension discovered that calcium is stored in tiny, discrete compartments. The doors to different compartments can be opened or closed by various drugs or natural chemicals produced by the body, releasing different amounts of calcium to control a broad range of physiological processes.

"These findings apply to virtually every cell in the body," said Dr. Mordecai P. Blaustein, professor and chairman of physiology at the University of Maryland School of Medicine. "This could lead to a better understanding of the physiological mechanisms underlying high blood pressure, heart failure, stroke, even aging."

He and Dr. Vera A. Golovina, research associate in physiology, report their findings in the March 14 issue of Science.

Most things cells do - contraction, secretion, reproduction, synthesis of proteins - rely on the release of the right amount of calcium at the right time and place. Calcium is stored in cells in a structure called the reticulum, a series of interconnected tubules and tiny sacs distributed throughout the cells.

Too much calcium can cause cell injury or even death. The amount of calcium in the reticulum that can get out of storage to do its work depends on the concentration of another potent chemical - sodium - between a cell’s outer membrane and the nearby intracellular calcium stores. Small changes in sodium concentration can produce large changes in calcium stores. Increasing sodium increases the amount of calcium that can be released from the stores.

In a related paper published in the March 4 issue of Proceedings of the National Academy of Sciences, Blaustein and Dr. Magdalena Juhaszova, research assistant professor in physiology at the University of Maryland School of Medicine, reported finding that although all cells have at least two of three varieties of sodium pump, these varieties are found in different places in the cells. The sodium pump is the body’s natural transport mechanism for moving sodium in or out of cells. One variety of sodium pump is extremely sensitive to endogenous ouabain, a ouabain-like human hormone that impairs a cell’s ability to get rid of excess sodium. Ouabain is a plant product related to digitalis, long used as a heart medication. Another form of sodium pump doesn’t respond to the minute amounts of this hormone found normally in the body.

Using sophisticated laboratory techniques to study smooth-muscle cells such as those in the walls of arteries, nerve cells and other brain cells known as astrocytes, the researchers pinpointed the locations of these various sodium pumps on each type of cell’s outer or plasma membrane. They found that the pumps that were most sensitive to ouabain are located next to the reticulum, suggesting that these pumps probably play a special role in regulating calcium levels.

"We used to think that all sodium pumps controlled the global sodium concentration in the cell," said Blaustein. "Now we know that some sodium pumps only control the sodium concentration in the space between the plasma membrane and the reticulum, and because of that, actually help to control calcium."

In 1991, Blaustein and colleagues reported their discovery that a ouabain-like compound is found naturally in minute concentrations in blood and that it affects a cell’s ability to get rid of excess sodium. Their discovery was regarded as an important new piece of the high blood-pressure puzzle.

"Now we’re starting to understand the crosstalk between the sodium pumps on the plasma membrane and the calcium stores in the reticulum," said Blaustein. "This will give us new insight into the whole story of cell signaling."

Blaustein and colleagues’ research is supported by the National Institutes of Health.

Story Source:

The above story is based on materials provided by University of Maryland at Baltimore. Note: Materials may be edited for content and length.

Cite This Page:

University of Maryland at Baltimore. "Calcium Storage, Release Mechanism Revealed." ScienceDaily. ScienceDaily, 13 March 1997. <www.sciencedaily.com/releases/1997/03/970313113049.htm>.
University of Maryland at Baltimore. (1997, March 13). Calcium Storage, Release Mechanism Revealed. ScienceDaily. Retrieved January 25, 2015 from www.sciencedaily.com/releases/1997/03/970313113049.htm
University of Maryland at Baltimore. "Calcium Storage, Release Mechanism Revealed." ScienceDaily. www.sciencedaily.com/releases/1997/03/970313113049.htm (accessed January 25, 2015).

Share This

More From ScienceDaily

More Health & Medicine News

Sunday, January 25, 2015

Featured Research

from universities, journals, and other organizations

Featured Videos

from AP, Reuters, AFP, and other news services

Disneyland Measles Outbreak Spreads To 5 States

Disneyland Measles Outbreak Spreads To 5 States

Newsy (Jan. 24, 2015) Much of the Disneyland measles outbreak is being blamed on the anti-vaccination movement. The CDC encourages just about everyone get immunized. Video provided by Newsy
Powered by NewsLook.com
Growing Measles Outbreak Worries Calif. Parents

Growing Measles Outbreak Worries Calif. Parents

AP (Jan. 23, 2015) Public health officials are rushing to contain a measles outbreak that has sickened 70 people across 6 states and Mexico. The AP&apos;s Raquel Maria Dillon has more. (Jan. 23) Video provided by AP
Powered by NewsLook.com
Smart Wristband to Shock Away Bad Habits

Smart Wristband to Shock Away Bad Habits

Reuters - Innovations Video Online (Jan. 23, 2015) A Boston start-up is developing a wristband they say will help users break bad habits by jolting them with an electric shock. Ben Gruber reports. Video provided by Reuters
Powered by NewsLook.com
This Is What It's Like To Date A Med Student

This Is What It's Like To Date A Med Student

BuzzFeed (Jan. 23, 2015) Dating is now speed-dating... or studying. Video provided by BuzzFeed
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.


Breaking News:

Strange & Offbeat Stories

Health & Medicine

Mind & Brain

Living & Well

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News


Free Subscriptions

Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile

Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?

Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins