How a low-protein diet predisposes offspring to adulthood hypertension
Testosterone in maternal plasma, demonstrating elevated levels in response to gestational protein restriction, is transported into placental zones, where part of the testosterone is inactivated by HSD17B2. The rest of the testosterone escapes the inactivation due to the reduced expression of Hsd17b2. Thus, excess testosterone goes into fetal circulation, affecting fetal growth and development and presumably predisposing the development of hypertension in offspring. Credit: Image concept: C. Yallampalli. Drawing: Alan Sheffield.
Studies have shown that the offspring of mothers on a low-protein diet are more likely to develop hypertension as adults. Now, Drs. Gao, Yallampalli, and Yallampalli of the University of Texas Medical Branch at Galveston report that in rats, the high maternal testosterone levels associated with a low-protein diet are caused by reduced activity of an enzyme that inactivates testosterone, allowing more testosterone to reach the fetus and increase the offspring's susceptibility to adulthood hypertension.
Fetal programming is a term used to describe the impact of maternal stress on an unborn child's physical characteristics at birth, as well as its long-term health. The placenta is thought to be a major contributor to fetal programming due to its critical roles in hormone production and nutrient transport, as well as its susceptibility to environmental disruptions.
Recently, a study found that protein restriction doubles the plasma testosterone levels in pregnant rats. Elevated testosterone levels are associated with pregnancy-related complications such as preeclampsia and polycystic ovarian syndrome in humans, and emerging evidence suggests that testosterone may play a role in fetal programming of hypertension.
Gao et al. hypothesized that the increased testosterone levels were caused either by increased activity of an enzyme that produces testosterone or by decreased activity of an enzyme that reduces testosterone, specifically Hsd17b2, which converts testosterone to a less potent androgen, androstenedione.
The team found that Hsd17b2 expression in rats was affected by protein restriction in two parts of the placenta. It was increased in the junctional zone, which is responsible for hormone production, but was reduced in the labyrinth zone, which is essential for nutrient transport from mother to fetus and also acts as a protective barrier.
Based on this novel finding, Gao et al. propose that the reduction in Hsd17b2 expression in the protective labyrinth zone may allow more testosterone to reach the fetus and play a role in fetal programming of hypertension.
The finding that Hsd17b2 was the only enzyme for testosterone production affected by gestational protein restriction suggests an important role for Hsd17b2 in regulating the testosterone levels at the maternal-fetal interface; further research is needed to determine its exact functions.
More information: Gao H, Yallampalli U, Yallampalli C. Gestational protein restriction reduces expression of Hsd17b2 in rat placental labyrinth. Biol Reprod 2012; (in press). Published online ahead of print 18 July 2012; DOI 10.1095/biolreprod.112.100479
Provided by Society for the Study of Reproduction
- Testosterone-fuelled infantile males might be a product of Mom's behaviour May 10, 2012 | not rated yet | 0
- Exploring the antidepressant effects of testosterone Apr 02, 2012 | not rated yet | 0
- Low testosterone levels could raise diabetes risk for men May 04, 2012 | not rated yet | 0
- High testosterone may mean shorter lives Apr 13, 2006 | not rated yet | 0
- Testosterone concentrations in men affected by genetic makeup Oct 06, 2011 | not rated yet | 0
- Motion perception revisited: High Phi effect challenges established motion perception assumptions Apr 23, 2013 | 3 / 5 (2) | 2
- Anything you can do I can do better: Neuromolecular foundations of the superiority illusion (Update) Apr 02, 2013 | 4.5 / 5 (11) | 5
- The visual system as economist: Neural resource allocation in visual adaptation Mar 30, 2013 | 5 / 5 (2) | 9
- Separate lives: Neuronal and organismal lifespans decoupled Mar 27, 2013 | 4.9 / 5 (8) | 0
- Sizing things up: The evolutionary neurobiology of scale invariance Feb 28, 2013 | 4.8 / 5 (10) | 14
How can there be a term called "intestinal metaplasia" of stomach
May 21, 2013 Hello everyone, Ok Stomach's normal epithelium is simple columnar, now in intestinal type of adenocarcinoma of stomach it undergoes "intestinal...
Pressure-volume curve: Elastic Recoil Pressure don't make sense
May 18, 2013 From pressure-volume curve of the lung and chest wall (attached photo), I don't understand why would the elastic recoil pressure of the lung is...
If you became brain-dead, would you want them to pull the plug?
May 17, 2013 I'd want the rest of me to stay alive. Sure it's a lousy way to live but it beats being all-the-way dead. Maybe if I make it 20 years they'll...
MRI bill question
May 15, 2013 Dear PFers, The hospital gave us a $12k bill for one MRI (head with contrast). The people I talked to at the hospital tell me that they do not...
Ratio of Hydrogen of Oxygen in Dessicated Animal Protein
May 13, 2013 As an experiment, for the past few months I've been consuming at least one portion of Jell-O or unflavored Knox gelatin per day. I'm 64, in very...
Alcohol and acetaminophen
May 13, 2013 Edit: sorry for the typo in the title , can't edit I looked around on google quite a bit and it's very hard to find precise information on the...
- More from Physics Forums - Medical Sciences
More news stories
New research at The University of Nottingham aimed at preventing harmful blood clots associated with heart disease and stroke has recently received a major funding boost from the British Heart Foundation.
Medical research 10 minutes ago | not rated yet | 0
Italian lawmakers on Wednesday gave their final approval to a law that allows limited use of a controversial type of stem cell therapy which has been condemned by many scientists but has given hope to families of terminally-ill ...
Medical research 25 minutes ago | not rated yet | 0
Trends in Helicobacter pylori (H. pylori) and smoking explain a significant proportion of the decline of intestinal-type noncardia gastric adenocarcinoma (NCGA) incidence in US men between 1978 and 2008, and are estimated ...
Medical research 14 hours ago | not rated yet | 0
Widely available in pharmacies and health stores, phosphatidylserine is a natural food supplement produced from beef, oysters, and soy. Proven to improve cognition and slow memory loss, it's a popular treatment for older ...
Medical research 19 hours ago | 5 / 5 (3) | 0 |
Researchers at Emory University have identified a protein that stimulates a pair of "orphan receptors" found in the brain, solving a long-standing biological puzzle and possibly leading to future treatments for neurological ...
Medical research 19 hours ago | 5 / 5 (1) | 0 |
A Japanese cancer specialist said Wednesday she has started the world's first clinical trial of a powerful, non-surgical, short-term radiation therapy for breast cancer.
5 minutes ago | not rated yet | 0
(AP)—The mayor of Portland, Ore., has conceded defeat in an effort to add fluoride to the city's drinking water.
55 minutes ago | not rated yet | 0
(AP)—Alabama health officials say a mysterious respiratory illness has left five people hospitalized and two dead in the southeastern part of the state.
35 minutes ago | not rated yet | 0
New mothers throughout Australia are needed to help QUT sleep researchers investigate whether the disrupted sleep experienced by mothers when caring for their new baby raises the risk of injury while driving.
3 minutes ago | not rated yet | 0
Is it permissible to harm one to save many? Those who tend to say "yes" when faced with this classic dilemma are likely to be deficient in a specific kind of empathy, according to a report published in the scientific journal ...
2 hours ago | not rated yet | 0 |
Phthalates: Study links chemicals widely found in plastics, processed food to elevated blood pressure in children, teens
Plastic additives known as phthalates (pronounced THAL-ates) are odorless, colorless and just about everywhere: They turn up in flooring, plastic cups, beach balls, plastic wrap, intravenous tubing and—according to the ...
3 hours ago | not rated yet | 1 |