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The following is the full transcript of an interview which was published in edited form in the November 2004 edition of the ISN newsletter.

: You are widely considered to be a world expert on phosphate transfer. Why did you focus on phosphate, originally?

Heini Murer

: I was driven at the start to look for questions of physiological relevance. I had the good luck to be in an institution with leading renal physiologists, with whom I studied problems related to renal phosphate handling. I had, as a trained biochemist, technical knowledge that allowed me to look at the problem from a more mechanistic/biochemical point of view.

After first screening for a variety of transporters, I started to focus on transporters that are physiologically regulated. Among this group was phosphate transport. I began to enter the area of physiology and pathophysiology, but I was entering from the direction of basic science. During the 25 years since then, my main research has focused on renal phosphate handling, from cellular and molecular events to physiology and pathophysiology.  This entails going back and forth between systems analysis at very different levels – organ, cell, molecule ? and always trying to integrate.

: It sounds like the nature of your research mandates a strong working background in disciplines related to nephrology, but in areas that other nephrologists might not have occasion to attend to on a regular basis.

HM

: Yes, this was probably the advantage of entering as a biochemist. The field was dominated at first by physiologists and nephrologists. Through a process of cooperation and cross-fertilization, we were able to see the need for, and develop, new techniques.

: Specialists are often quite vigilant in guarding the boundaries of their disciplines. Did you encounter resistance along the way?

HM

: Of course. Coming from basic research into a medical environment, I experienced difficulties being accepted. Fortunately, people soon realized that I was simply using a different approach to understand a problem with physiological and pathophysiological relevance; they saw that the technique was secondary to the progress being made. As soon as people became familiar with this approach, I was accepted and integrated. Most people today probably don?t even realize that I?m not an MD!

: How long did it take you to overcome this initial resistance ? a few years or a decade?

HM

: At the Max Planck Institute in Frankfurt this was easy. There I was a biochemist among medical professionals in an environment dominated by basic science interests. Later, when I was on my own in a medical institution, it took more time. Something like four to six years. However, I was able to overcome the problem by not making it a matter of prestige and by not arguing whether a physiological or a biochemical approach is better. I advocated and explained the need for both.

: Looking back, what was the most exciting thing that you discovered?

HM

: Early on in my career, as a biochemist moving into physiology, I used biochemical techniques, such as membrane fractionation and membrane isolation, to describe physiological functions such as simple membrane transport. Together with Rolf Kinne, I discovered many transport functions at the functional level. This was a very exciting phase that lasted 3-4 years. One of the most exciting discoveries was the first description of an activity that, according to physiological functions, had to be there: sodium proton exchange. We were the first to really document that it existed.

The second thing was the realization that with our techniques we could even start to think of analyzing physiology and pathophysiology. We made the surprising observation that whenever a function undergoes a change at the level of the renal tubule ? here we isolated membrane vesicles to study the transport function – the regulation of transport is retained and could be studied at the membrane level. This of course opened a lot of possibilities that we continue to explore to this day, towards understanding physiological and pathophysiological mechanisms and regulation at the molecular level. Always traveling from the organ or organism to the cell, to the membrane, now also to the molecule because in the meantime we have managed to clone transporters, and back again.

: It sounds like a fair amount of the early work you did was pioneering in nature. Did you set out to expand boundaries from the start?

HM

: That was always our motivation.  I would never try to convince myself or my co-workers not to go into new territory. This was the driving force for cloning the transporters. This was the driving force afterwards to study the regulation at the molecular level. This is still our motivation. I am considered a ?digger? because I don?t delve into thousands of transport systems and make observations. I prefer to stick to one area, which for the last 10-15 years has been phosphate reabsorption, and to understand this mechanism in as much detail as possible.

: Would you say that the medical and research community is more or less open to this kind of pioneering work today than when you first started?

HM

: A lot has to do with financial support. At the start of their careers, people tend towards techniques and methods that produce fast results. People hop like butterflies from one observation to the next and do not invest too much in new developments. It?s the privilege of being a more established scientist ? also the advantage of being in an environment with healthy financial support, including both hard and soft money ? to focus primarily on new developments. Perhaps it is even our duty.

: Beyond being known as a ?digger? you also have the reputation of being a climber, hiker, and skier. In other words, someone who is passionate about sport.

HM

: I?m a hobby-driven person. Scientific research is one of my hobbies. Since I was young, sport has been another. It?s not difficult to combine these two hobbies. I have a lot of friends from the world of science who also like to jog or visit the fitness center. I have a very good friend with whom I share a renal research interest but with whom I also go mountaineering!

: Sounds holistic.

HM

: It has a lot to do with the kind of person you are. In science one?s choice of career depends greatly on how one communicates with other people. It?s the same in your personal choices. For instance, I would never have a personal hobby that forces me to be on my own. I exercise in order to be fit enough to ski, mountaineer, or hike with my colleagues.

: And to help you survive a WCN.

HM

: Of course. There I?ll be in the hotel fitness room every morning. People know where to find me!