Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Sheep stress programs lamb

23.04.2002


Early life of fetus affects organs’ future health.

Sheep stressed in early pregnancy bear lambs with stunted kidneys that predispose them to high blood pressure Australian researchers have shown. The finding adds to growing evidence that early fetal life influences adult health.

Marelyn Wintour of the University of Melbourne subjected 4-week-pregnant ewes to two stressful days by infusing them with the hormone cortisol. Their lambs developed high blood pressure at 5 months of age, she told the Experimental Biology 2002 meeting in New Orleans on Sunday.



Just before birth, genes that regulate kidney development and blood pressure are more active than normal, she and her colleagues went on to find. As adults, the animals had only two-thirds of the normal number of fluid-filtering units in their kidneys.

Stress forces the cells destined to form the kidney to mature too fast, Wintour believes. This would give the organ less time to grow. "We accelerated maturation by overexpression of these genes," says Wintour. Over time, the inability of the kidney to expel water and salts efficiently may cause blood pressure to rise.

Wintour and others have explored the effects of maternal stress on the fetus before, but this is the first test of the effect of a natural hormone in a large animal. A 4-kilogram lamb weighs roughly the same as a human baby.

Premature physique

Fetal programming is the idea that early events in fetal growth affect an adult’s susceptibility to disease. It was discussed at two sessions of the New Orleans meeting.

Many large epidemiology studies have shown that poor nutrition, which limits fetal growth and reduces birth weight, is associated with increased risk of heart disease, hypertension and adult-onset diabetes.

"It takes it away from the idea that [these diseases] are retribution for adults," says epidemiologist David Barker of the University of Southampton, UK, who originally proposed the fetal-programming hypothesis.

Barker suggests that when conditions are tough - when food is scarce or levels of stress hormones are high, say - the fetus adapts to ensure its survival, perhaps by diverting blood or nutrients to the brain at the expense of other organs. These shifts cause permanent changes in the adult organs. "Everyone has been changed by their experience in fetal life," maintains Barker.

How fetal tissues are permanently altered remains largely unknown. Cells that give rise to an organ may be susceptible to external signals, suggests paediatric researcher Rebecca Simmons of the University of Pennsylvannia in Philadelphia. Anything that interrupts these signals could alter the cell types that survive to contribute to the organ.

This is consistent with Wintour’s finding that kidney development can be altered by stress that occurs even before it has formed. "It was surprising to me that the early time is the critical one," she says.

At the equivalent point in human pregnancy - at around 5-7 weeks - many women are unaware of their condition. Pregnant women who know they are stressed should try and take a little time out to relax or sleep, Wintour suggests.

HELEN PEARSON | © Nature News Service

More articles from Life Sciences:

nachricht Opening the cavity floodgates
23.01.2018 | Albert-Ludwigs-Universität Freiburg im Breisgau

nachricht Incentive to Move
23.01.2018 | Albert-Ludwigs-Universität Freiburg im Breisgau

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Optical Nanoscope Allows Imaging of Quantum Dots

Physicists have developed a technique based on optical microscopy that can be used to create images of atoms on the nanoscale. In particular, the new method allows the imaging of quantum dots in a semiconductor chip. Together with colleagues from the University of Bochum, scientists from the University of Basel’s Department of Physics and the Swiss Nanoscience Institute reported the findings in the journal Nature Photonics.

Microscopes allow us to see structures that are otherwise invisible to the human eye. However, conventional optical microscopes cannot be used to image...

Im Focus: Artificial agent designs quantum experiments

On the way to an intelligent laboratory, physicists from Innsbruck and Vienna present an artificial agent that autonomously designs quantum experiments. In initial experiments, the system has independently (re)discovered experimental techniques that are nowadays standard in modern quantum optical laboratories. This shows how machines could play a more creative role in research in the future.

We carry smartphones in our pockets, the streets are dotted with semi-autonomous cars, but in the research laboratory experiments are still being designed by...

Im Focus: Scientists decipher key principle behind reaction of metalloenzymes

So-called pre-distorted states accelerate photochemical reactions too

What enables electrons to be transferred swiftly, for example during photosynthesis? An interdisciplinary team of researchers has worked out the details of how...

Im Focus: The first precise measurement of a single molecule's effective charge

For the first time, scientists have precisely measured the effective electrical charge of a single molecule in solution. This fundamental insight of an SNSF Professor could also pave the way for future medical diagnostics.

Electrical charge is one of the key properties that allows molecules to interact. Life itself depends on this phenomenon: many biological processes involve...

Im Focus: Paradigm shift in Paris: Encouraging an holistic view of laser machining

At the JEC World Composite Show in Paris in March 2018, the Fraunhofer Institute for Laser Technology ILT will be focusing on the latest trends and innovations in laser machining of composites. Among other things, researchers at the booth shared with the Aachen Center for Integrative Lightweight Production (AZL) will demonstrate how lasers can be used for joining, structuring, cutting and drilling composite materials.

No other industry has attracted as much public attention to composite materials as the automotive industry, which along with the aerospace industry is a driver...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

10th International Symposium: “Advanced Battery Power – Kraftwerk Batterie” Münster, 10-11 April 2018

08.01.2018 | Event News

See, understand and experience the work of the future

11.12.2017 | Event News

Innovative strategies to tackle parasitic worms

08.12.2017 | Event News

 
Latest News

Researchers reveal how microbes cope in phosphorus-deficient tropical soil

23.01.2018 | Earth Sciences

Opening the cavity floodgates

23.01.2018 | Life Sciences

Siberian scientists suggested a new method for synthesizing a promising magnetic material

23.01.2018 | Materials Sciences

VideoLinks Science & Research
Overview of more VideoLinks >>>