The DHEA counters hypertension

(Le Express.fr,24/7/03)

This hormone could look after the excess of tension of the pulmonary arteries. Researchers of Bordeaux have just proven of it on an animal model. Remain to confirm at the man

Is this the effect of the DHEA? At 76 years spent, Pr Etienne-Emile Baulieu lost anything neither of its ardour nor of its curiosity. In its office of the Academy of Science, quay Conti (Paris VIe), celebrates it endocrinologist, who acknowledges to take each day 25 Mg of dehydroepiandrosterone (the erudite name of this substance), holds up the study of two young researchers of Bordeaux, Sebastien Bonnet and Eric Dumas-of-the-Castling. It will be published soon in prestigious Proceedings of the National Academy of Sciences (reports of the American Academy of Science).

"Never I did not see a scientific article accepted also quickly by a reading panel, specify it, filled with wonder. This work opens an extraordinary track. They reveal a property of the prasterone (another name of DHEA) which could make it possible to treat pulmonary arterial hypertension." Admittedly, the experiments were undertaken until now only on rats. But from the clinical trials will be led at the man to the university hospital complex of Bordeaux. This discovery starts again the interest for a molecule, at one time presented like the "Fountain of Youth", the "pill miracle", able to repair the insults of the years, but very decriee these two last years.

Sebastien Bonnet and Eric Dumas-of-the-Castling, of the laboratory of physiology of the university Bordeaux II, chose to evaluate the effects of the DHEA on pulmonary arterial hypertension, a very widespread pathology among large smokers. The contracting of the bronchi causes respiratory difficulties which, in their turn, can involve an excessive increase in the blood pressure. This complication touches 50 000 French. The risk is mortal.

In their experiments, the researchers of Bordeaux reproduced the process while making breathe with rats of the air low in oxygen. The animals which had received an amount of DHEA did not develop hypertension. Those which had been exposed without precaution were partly cured after injection of this substance. How does it act? Answer of Sebastien Bonnet and Eric Dumas-of-the-Castling: the DHEA modulates certain ionic channels, these tiny switches which control the electric signals in the body.

Quantitatively, it is the most significant hormone of the human body

For Michel Lazdunski, director of Institute of the molecular and cellular pharmacology of CNRS (Nice-Sophia-Antipolis), this discovery offers new prospects not only to look after pulmonary arterial hypertension, but also to include/understand the mode of action of the DHEA. "We knew already that this molecule could open ionic channels, it explains. For the first time, work shows that it intervenes in a precise pathology. As the ionic channels are implied in a multitude of functions of the organization, it is not impossible that the DHEA acts thus on a large variety of cells, not only cardiovascular, but so nervous or muscular." Remain to bring the scientific proof of it!

The history of the prasterone is old. But the researchers are still far from to have bored all its mysteries. This natural hormone was discovered in 1934 by a German, Dr. Adolf Butenandt. Quantitatively, it is the most significant hormone of the human body. In blood, it is especially present in its sulphated form (Dhea-s). One must with Pr Etienne-Emile Baulieu have shown, in 1960, that the molecule was secreted by the glands suprarenals (small bodies located above each kidney). Another certainty: the rate of DHEA is a biological marker of the age. Up to 7-8 years, the children practically do not have any. The concentration reaches a peak between 25 and 30 years and declines gradually. At 80 years, it does not represent any more but from 10 to 20% of its maximum level. The presence of prasterone is stronger at the man than at the woman.

"the benefits of a catch of DHEA are not always quantifiable objectively"

Is there a therapeutic interest to make up this deficit growing by the ingestion of gelules of synthetic DHEA? To date, only one great study - baptized DHEAge - was carried out on the subject in France. Carried out by Pr Francoise Forette, gerontologist, and Pr Etienne-Emile Baulieu, it included a population of 280 volunteers, old from 60 to 79 years. A daily amount of 50 Mg their was given during one year. Conclusion of this work, published in April 2000: the recipients of the treatment are the women, in particular those which exceed 70 years. The DHEA improves their bone tissue metabolism, the quality of their skin and their libido. The effects on the organization appear limited. Is it necessary for as much "disadvising the regulation of the DHEA within the framework of the fight against the effects of ageing", as wrote it, in August 2001, the director of the French Agency of the medical safety of the products of health (Afssaps)? Certainly not. The 50 000 French who, currently, take this substance regularly do not have anything to fear. The DHEAge study has the merit to show that this molecule is not dangerous. There was neither accident nor excessive accumulation of hormones.

This work reveals, in addition, the difficulties of evaluating a substance which acts as very many points of the organization. "the benefits of a catch of DHEA are not always quantifiable objectively, observes Dr. Christophe de Jaeger, doctor geriatre, author of the Techniques of fight against ageing (PUF) and of the DHEA, myths and realities (Albin Michel). Our patients feel a general improvement and a multitude of small positive effects. Some do not make any more bronchitis, others do not know any more problems of articulations."

The DHEAge study poses another methodological problem. All the volunteers received an identical treatment, whereas the deficit of DHEA varies from one individual to another. The variation can be 1 to 20 for the same age bracket! That distorts the final result partly. The catches would have in the future to be modulated, in order to take account of these differences. The more so as before any regulation of DHEA the doctors require a blood analysis to measure the rate of prasterone and to adapt the amount to be taken.

Complementary studies must be undertaken on the effects of the DHEA at the man. The obstacle to carry them out is due to the difficulties of financing. "It is a natural molecule, therefore nonpatentable. It is in consequence impossible to make deal with work by a pharmaceutical laboratory ", underlines Pr Baulieu. DHEAge could be done only with the support of the area Island-of-France, the French Foundation for medical research and of Artemis (Pinault group). In order to continue his research, the president of the Academy of Science needs new patrons. If not, France is likely to lose its position in this field. There is urgency. Fault of having found a station in the Hexagon, Sebastien Bonnet, one of the two decouvreurs of Bordeaux, soon will be exiled in Canada....