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 Discovery of a Key Regulatory Gene in Cardiac Valve Formation
24.05.2017 | Universität Basel

nachricht Carcinogenic soot particles from GDI engines
24.05.2017 | Empa - Eidgenössische Materialprüfungs- und Forschungsanstalt

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: A quantum walk of photons

Physicists from the University of Würzburg are capable of generating identical looking single light particles at the push of a button. Two new studies now demonstrate the potential this method holds.

The quantum computer has fuelled the imagination of scientists for decades: It is based on fundamentally different phenomena than a conventional computer....

Im Focus: Turmoil in sluggish electrons’ existence

An international team of physicists has monitored the scattering behaviour of electrons in a non-conducting material in real-time. Their insights could be beneficial for radiotherapy.

We can refer to electrons in non-conducting materials as ‘sluggish’. Typically, they remain fixed in a location, deep inside an atomic composite. It is hence...

Im Focus: Wafer-thin Magnetic Materials Developed for Future Quantum Technologies

Two-dimensional magnetic structures are regarded as a promising material for new types of data storage, since the magnetic properties of individual molecular building blocks can be investigated and modified. For the first time, researchers have now produced a wafer-thin ferrimagnet, in which molecules with different magnetic centers arrange themselves on a gold surface to form a checkerboard pattern. Scientists at the Swiss Nanoscience Institute at the University of Basel and the Paul Scherrer Institute published their findings in the journal Nature Communications.

Ferrimagnets are composed of two centers which are magnetized at different strengths and point in opposing directions. Two-dimensional, quasi-flat ferrimagnets...

Im Focus: World's thinnest hologram paves path to new 3-D world

Nano-hologram paves way for integration of 3-D holography into everyday electronics

An Australian-Chinese research team has created the world's thinnest hologram, paving the way towards the integration of 3D holography into everyday...

Im Focus: Using graphene to create quantum bits

In the race to produce a quantum computer, a number of projects are seeking a way to create quantum bits -- or qubits -- that are stable, meaning they are not much affected by changes in their environment. This normally needs highly nonlinear non-dissipative elements capable of functioning at very low temperatures.

In pursuit of this goal, researchers at EPFL's Laboratory of Photonics and Quantum Measurements LPQM (STI/SB), have investigated a nonlinear graphene-based...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Marine Conservation: IASS Contributes to UN Ocean Conference in New York on 5-9 June

24.05.2017 | Event News

AWK Aachen Machine Tool Colloquium 2017: Internet of Production for Agile Enterprises

23.05.2017 | Event News

Dortmund MST Conference presents Individualized Healthcare Solutions with micro and nanotechnology

22.05.2017 | Event News

 
Latest News

Physicists discover mechanism behind granular capillary effect

24.05.2017 | Physics and Astronomy

Measured for the first time: Direction of light waves changed by quantum effect

24.05.2017 | Physics and Astronomy

Marine Conservation: IASS Contributes to UN Ocean Conference in New York on 5-9 June

24.05.2017 | Event News

VideoLinks
B2B-VideoLinks
More VideoLinks >>>