Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Road wends its way through stomach

20.09.2006
A computer model or "virtual stomach" revealed a central "road" in the human stomach, dubbed the Magenstrasse, that could explain why pharmaceuticals sometimes have a large variability in drug activation times, according to a team creating computer simulations of stomach contractions.

"We are predicting variables that we wish we could measure, but we cannot," says Dr. James G. Brasseur, professor of mechanical engineering, bioengineering and mathematics at Penn State. "Now that we know the Magenstrasse exists, we can look for it, but, it will not be easy to measure its existence and could require expensive technology."

Brasseur, working with Anupam Pal, research associate, Penn State and Bertil Abrahamsson, AstraZeneca, was interested in how the stomach empties its contents and how material passes from the stomach into the small intestines.

"The sphincter between the stomach and the small intestine is interactive," said Brasseur. "The sphincter opens and closes in a controlled way to regulate the flow of nutrient to the small intestines. Sensor cells in the intestines modulate the opening and closing."

... more about:
»Brasseur »Magenstrasse »intestine »stomach

Two types of muscle contractions control food movement in the stomach. One type of contraction, antral contractions, occur in the lower portion of the stomach and break down and mix stomach contents. The other type of contraction, fundic contractions, is over the upper surface of the stomach. It was thought that the fundic contractions move food from the top of the stomach where it enters from the esophagus, to the bottom of the stomach where the chyme leaves and enters the small intestine. The assumption was that particles left the stomach in the same order they entered the stomach.

The researchers modeled the stomach contents and discovered that a narrow path forms in the center of the stomach along which food exits the stomach more rapidly than the regions near the walls of the stomach. They used MRI data from human subjects to create the proper geometry of the muscle contractions.

"We looked at a ten-minute window of digestion and we tagged all the particles as they left the virtual stomach," said Brasseur. "We then reversed the flow on the computer and saw where the particles came from."

In essence they ran the simulation backwards and were surprised to see a central road appear. Those particles in the virtual stomach that were on the central road, exited the stomach in 10 minutes. The Magenstrasse extended all the way from the stomach's exit up to the top of the stomach's fundus. Material that entered the stomach off this Magenstrasse could remain in the stomach a long time, even hours in the real stomach.

"This discovery might explain observed high variability in drug initiation time, and may have important implications to both drug delivery and digestion," the researchers report online in the Journal of Biomechanics. The paper will appear in a print edition in 2007.

Because most drugs target the small intestines for absorption, a pill disintegrates in the stomach and activates in the small intestines. With this new understanding of how the stomach works, where in the stomach a pill or capsule disintegrates becomes very important. Drug delivery times may differ from 10 minutes to hours depending on location.

"Therefore, drugs released on the Magenstrasse will enter the duodenum rapidly and at a high concentration," the researchers report. "Drug released off the gastric emptying Magenstrasse, however, will mix well and enter the duodenum much later, at low concentration."

For some drugs, rapid release is important, for others, slow release over long periods of time is the desired outcome.

"If you do not know a Magenstrasse exists, you will not factor it into the designs," says Brasseur. "Now that we know, perhaps researchers can design pills with higher densities to sit around at the bottom of the stomach, outside the Magenstrasse, and let the drug out slowly."

A'ndrea Elyse Messer | EurekAlert!
Further information:
http://www.psu.edu

Further reports about: Brasseur Magenstrasse intestine stomach

More articles from Life Sciences:

nachricht Scientists unlock ability to generate new sensory hair cells
22.02.2017 | Brigham and Women's Hospital

nachricht New insights into the information processing of motor neurons
22.02.2017 | Max Planck Florida Institute for Neuroscience

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Breakthrough with a chain of gold atoms

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

Im Focus: DNA repair: a new letter in the cell alphabet

Results reveal how discoveries may be hidden in scientific “blind spots”

Cells need to repair damaged DNA in our genes to prevent the development of cancer and other diseases. Our cells therefore activate and send “repair-proteins”...

Im Focus: Dresdner scientists print tomorrow’s world

The Fraunhofer IWS Dresden and Technische Universität Dresden inaugurated their jointly operated Center for Additive Manufacturing Dresden (AMCD) with a festive ceremony on February 7, 2017. Scientists from various disciplines perform research on materials, additive manufacturing processes and innovative technologies, which build up components in a layer by layer process. This technology opens up new horizons for component design and combinations of functions. For example during fabrication, electrical conductors and sensors are already able to be additively manufactured into components. They provide information about stress conditions of a product during operation.

The 3D-printing technology, or additive manufacturing as it is often called, has long made the step out of scientific research laboratories into industrial...

Im Focus: Mimicking nature's cellular architectures via 3-D printing

Research offers new level of control over the structure of 3-D printed materials

Nature does amazing things with limited design materials. Grass, for example, can support its own weight, resist strong wind loads, and recover after being...

Im Focus: Three Magnetic States for Each Hole

Nanometer-scale magnetic perforated grids could create new possibilities for computing. Together with international colleagues, scientists from the Helmholtz Zentrum Dresden-Rossendorf (HZDR) have shown how a cobalt grid can be reliably programmed at room temperature. In addition they discovered that for every hole ("antidot") three magnetic states can be configured. The results have been published in the journal "Scientific Reports".

Physicist Dr. Rantej Bali from the HZDR, together with scientists from Singapore and Australia, designed a special grid structure in a thin layer of cobalt in...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Booth and panel discussion – The Lindau Nobel Laureate Meetings at the AAAS 2017 Annual Meeting

13.02.2017 | Event News

Complex Loading versus Hidden Reserves

10.02.2017 | Event News

International Conference on Crystal Growth in Freiburg

09.02.2017 | Event News

 
Latest News

Microhotplates for a smart gas sensor

22.02.2017 | Power and Electrical Engineering

Scientists unlock ability to generate new sensory hair cells

22.02.2017 | Life Sciences

Prediction: More gas-giants will be found orbiting Sun-like stars

22.02.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>