I have spent most of my career working on the function of microvessels, which make up about 80-90 percent of the blood circulation. In the last 10 years I have concentrated mainly on the specificities of the cerebral circulation, said Dr. Ákos Koller, Head of the Microcirculation Laboratory of the Institute of Translational Medicine, Professor at the Faculty of Health Sciences (ETK), former Vice-Dean of the Faculty of Medicine, Doctor of the Hungarian Academy of Sciences. In 2019, his research achievements earned him the Malpighi Award of the European Society for Microcirculation, while his research and teaching work was recognized with the Albert Szent-Györgyi Medical Award in 2021. Last spring he received the Eugene M. Landis Research Award from the American Microcirculatory Society.
The prize he has just received, named after Carl J. Wiggers, the founder of the Cardiovascular Section of the American Physiological Society, will be presented to him in spring 2025 at the society’s annual American Physiology Summit in Baltimore, USA.
“It can be seen as a kind of merit award, which is a reward for the scientific achievements of my career and the achievements of my students. Having students, I feel, is a vindication of your work, because you have people to carry on your achievements. And of course, it is important to have students because they make you work even harder,” said the professor, who is still actively involved in university talent management, especially in doctoral and TDK (Students’ Scientific Association) programs.
The discovery and verification of the role of shear stress in the regulation of microvascular circulation is considered one of his greatest scientific achievements. That is, the experimental demonstration that it is not only the magnitude of the pressure that regulates the circulation, but also the speed of the flow, and that the resulting force on the vessel wall – i.e. shear stress, or, in simple terms, friction – also plays a major role in the amount of circulatory energy lost in small and microvessels, which may put more strain on the heart. Another important discovery of his was that cerebral microvessels behave in exactly the opposite way to the small vessels of the heart. Because of the closed skull, the blood vessels cannot widen much, so they tend to contract when the flow increases, and provide the necessary blood flow by increasing the flow rate. “Impairment of this function may play a role in traumatic brain injury, migraine, hypertonia, diabetes, and preeclampsia, which also sets the direction for my research. We are currently researching the latter at the Institute of Translational Medicine led by Dr. Zoltán Benyó,” he added.
In recent years, he has also turned his interest from basic research to clinical research. In this context, he said:
I have a desire to research in humans what we have discovered in animal tests.
Therefore, together – among others – with Dr. Róbert Debreczeni and his group (Department of Neurology, Semmelweis University), they are using transcranial Doppler to study changes in cerebral blood flow in humans in various diseases. In a decade-long collaboration with the New York Medical College, he and his fellow researchers are investigating the consequences of damage to the glycocalyx layer (composed of lipopolysaccharides) that is located on the inner surface of blood vessels, on the exterior of the endothelium, such as increased fluid and protein efflux leading to edema. To reduce this, they have developed a potential new therapeutic option using liposomes to restore the structure and function of the glycocalyx.
He is proud that for more than 20 years he has organized his research, including animal models, in such a way as to take into account the differences in the functioning of the male and female microcirculation. This year, the American Physiological Society took the initiative by proposing that researchers in different disciplines should publish research results only if they have conducted experiments with female animals, Dr. Ákos Koller said. He added that this was important because treatment guidelines for certain diseases were often tailored to healthy men aged 25, and doctors had to adjust the treatment and medication of patients of different ages and sexes accordingly.
Melinda Katalin Kiss
Translation: Dr. Balázs Csizmadia
Photos by Boglárka Zellei – Semmelweis University
Illustration by Dr. Gabriella Dörnyei, Dr. Ákos Koller – Semmelweis University
