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 Symbiotic bacteria: from hitchhiker to beetle bodyguard
28.04.2017 | Johannes Gutenberg-Universität Mainz

nachricht Nose2Brain – Better Therapy for Multiple Sclerosis
28.04.2017 | Fraunhofer-Institut für Grenzflächen- und Bioverfahrenstechnik IGB

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Making lightweight construction suitable for series production

More and more automobile companies are focusing on body parts made of carbon fiber reinforced plastics (CFRP). However, manufacturing and repair costs must be further reduced in order to make CFRP more economical in use. Together with the Volkswagen AG and five other partners in the project HolQueSt 3D, the Laser Zentrum Hannover e.V. (LZH) has developed laser processes for the automatic trimming, drilling and repair of three-dimensional components.

Automated manufacturing processes are the basis for ultimately establishing the series production of CFRP components. In the project HolQueSt 3D, the LZH has...

Im Focus: Wonder material? Novel nanotube structure strengthens thin films for flexible electronics

Reflecting the structure of composites found in nature and the ancient world, researchers at the University of Illinois at Urbana-Champaign have synthesized thin carbon nanotube (CNT) textiles that exhibit both high electrical conductivity and a level of toughness that is about fifty times higher than copper films, currently used in electronics.

"The structural robustness of thin metal films has significant importance for the reliable operation of smart skin and flexible electronics including...

Im Focus: Deep inside Galaxy M87

The nearby, giant radio galaxy M87 hosts a supermassive black hole (BH) and is well-known for its bright jet dominating the spectrum over ten orders of magnitude in frequency. Due to its proximity, jet prominence, and the large black hole mass, M87 is the best laboratory for investigating the formation, acceleration, and collimation of relativistic jets. A research team led by Silke Britzen from the Max Planck Institute for Radio Astronomy in Bonn, Germany, has found strong indication for turbulent processes connecting the accretion disk and the jet of that galaxy providing insights into the longstanding problem of the origin of astrophysical jets.

Supermassive black holes form some of the most enigmatic phenomena in astrophysics. Their enormous energy output is supposed to be generated by the...

Im Focus: A Quantum Low Pass for Photons

Physicists in Garching observe novel quantum effect that limits the number of emitted photons.

The probability to find a certain number of photons inside a laser pulse usually corresponds to a classical distribution of independent events, the so-called...

Im Focus: Microprocessors based on a layer of just three atoms

Microprocessors based on atomically thin materials hold the promise of the evolution of traditional processors as well as new applications in the field of flexible electronics. Now, a TU Wien research team led by Thomas Müller has made a breakthrough in this field as part of an ongoing research project.

Two-dimensional materials, or 2D materials for short, are extremely versatile, although – or often more precisely because – they are made up of just one or a...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Fighting drug resistant tuberculosis – InfectoGnostics meets MYCO-NET² partners in Peru

28.04.2017 | Event News

Expert meeting “Health Business Connect” will connect international medical technology companies

20.04.2017 | Event News

Wenn der Computer das Gehirn austrickst

18.04.2017 | Event News

 
Latest News

Wireless power can drive tiny electronic devices in the GI tract

28.04.2017 | Medical Engineering

Ice cave in Transylvania yields window into region's past

28.04.2017 | Earth Sciences

Nose2Brain – Better Therapy for Multiple Sclerosis

28.04.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>