Lab Spotlight: Professor Christian Aalkjær

Advancing Vascular Science Through Human Arteries, Sex Differences and Even Giraffes 

With more than four decades of experience studying the smallest and often most overlooked blood vessels in the body, Professor Christian Aalkjær has built a career around one central belief... to truly understand vascular disease, we must study real human vessels. As a long-time DMT customer and a pioneer in resistance artery research, his work continues to shape how scientists think about vascular structure, function, and sex-specific disease mechanisms. 

A Lifelong Focus on Small Arteries 
Professor Aalkjær’s research centers on small arteries, the resistance vessels that play a critical role in regulating blood pressure and tissue perfusion. His journey into this field was heavily influenced by his mentor, Professor Mulvany  - one of the founding figures in modern myograph-based vascular research. 

Over the years, Professor Aalkjær became particularly intrigued by sex differences in vascular structure. What began as a curiosity quickly became a defining theme of his work. One of the most striking findings was that male and female vessels are both structurally and functionally different. These differences are not merely anatomical, they help explain why certain vascular diseases are more prevalent in one sex than the other. 

To study these questions properly, his lab relies on human tissue. Before experiments can even begin, ethical approval is required, and patients voluntarily donate small biopsies often taken from the gluteal region to advance scientific understanding. “It’s critical that we study human vessels,” he emphasizes. “Animal models are valuable, but they don’t tell the whole story.” 

Unexpected Insights into Sex-Specific Disease 
One of the most surprising realizations from Professor Aalkjær’s research is just how differently vascular disease can manifest between males and females. Some diseases occur almost exclusively in women, while others disproportionately affect men. His work aims to uncover why examining how structural and functional differences in blood vessels may predispose each sex to specific conditions. 

This line of research continues to challenge long-held assumptions in vascular physiology and highlights the importance of designing experiments that account for biological sex, rather than treating it as a secondary variable. 

From the Lab to the Savannah: The Giraffe Experiments 
Among Professor Aalkjær’s most well-known and memorable experiments is one that began with an unlikely source of inspiration... giraffes. 

Inspired by Professor Folkow, whom he describes as one of his scientific heros, Professor Aalkjær became fascinated by how giraffes manage an extreme blood pressure. Adult giraffes have a mean arterial pressure of around 200 mmHg, roughly double that of humans. How their vessels withstand such pressure without constant vascular damage posed a compelling physiological puzzle. 

This curiosity led to an ambitious expedition to South Africa, where his team worked with specialized veterinarians from Denmark and South Africa to study anesthetized giraffes in quarantine facilities. Using advanced instrumentation, they placed flow and pressure sensors and carefully extracted small arteries from different regions of the body including the brain, neck and hooves. 

The findings were remarkable. Brain vessels operate under relatively low pressure, while the vessels in the hooves endure extremely high pressures, revealing dramatic regional adaptations within the same animal. These insights have had lasting implications for understanding pressure regulation and vascular remodeling. ​

Challenges Behind the Science 
Like most long-term research programs, Professor Aalkjær’s work has not been without challenges. Securing funding remains a constant hurdle, particularly when grant committees struggle to fully engage with complex study designs. Building and maintaining a strong lab team is another ongoing effort selecting researchers who are not only technically skilled but resilient in the face of failure. 

“Many experiments won’t work,” he says candidly. “You have to be prepared for frustration.” 

His approach to overcoming these challenges is rooted in collaboration and perspective supporting former students, helping colleagues troubleshoot experiments, and celebrating successes whenever they come. 

Why DMT Equipment Matters 
DMT systems have played a key role in enabling Professor Aalkjær’s research, particularly their versatility and precision. His lab uses a specially modified myograph system that allows electrical stimulation of the tissue, and in this way investigates how nerves in the vessel wall can control the activity of the smooth muscle cells in the arterial wall. 

This capability is essential for studying neurovascular interactions and preserving physiological relevance something Professor Aalkjær considers indispensable when working with delicate human arteries. 

A Lasting Impact 
When asked what he is most proud of, his answer is simple but powerful... 'bringing human arteries into the lab' By prioritizing human tissue and physiological relevance, Professor Aalkjær has helped move vascular science closer to the conditions that actually matter for patients. 

Advice for the Next Generation 
For aspiring researchers, his advice is refreshingly honest: “Be prepared for many frustrations.” Experiments will fail. Data will be messy. Progress will be slow. But success when it comes is worth celebrating. Just as importantly, he encourages young scientists to support one another and recognize good work when they see it. 

After more than 40 years in the field, Professor Christian Aalkjær’s work continues to exemplify curiosity, rigor, and a deep commitment to advancing vascular science one small artery at a time.