Louis Tobian
Year: April 6th, 2006
Location: Minneapolis, Minnesota
Interviewed by: Blackburn, Henry
Abstract
This is a jolly meeting with pioneer hypertensionologist Lou Tobian, ranging over the history of research on mechanisms, his role in studying the sodium and water content of arteries and regulation by juxtaglomerular cells. He speaks fondly of his ‘conversion’ to the evolutionary medical concept of adaptations to hunter-gatherer lifestyles and how he applied the concept to his studies of the protective effect of potassium in stroke prone rats.
We speak of the pioneers Dahl, Freis, Harrison, Meneely, Yamori, and the people now doing notable work. He finds colleagues in his skepticism about the reality of a specific Metabolic Syndrome. He proposes a brain mechanism mediating the long term effect of the trauma of ‘slightly elevated’ pressure of modern humans, due in part to a lifetime of high salt intake. He marvels about how much is still poorly known about hypertension. And he is richly quotable in a small sample below. (Henry Blackburn)
Quotes
LT: But, I said to myself, “High blood pressure is a disease of arteries and he didn’t measure arteries at all.” So Louis got some more rats and learned how to do it and I did sodium, potassium, water content ….
HB: In macerated arteries?
LT: I think what we did was extract them…You know, you’d get the wet weight, dry weight, you’d get the water and then you’d extract and you can relate it back to dry weight. So, lo and behold, the arteries had more water and they had more sodium. And this was kind of my first ten-strike and I got the idea that if you put a lot of water in the wall of an artery it would make the lumens smaller and it could be one of the causes of increased resistance.
LT: The only reason I say that is you go down to the upper Amazon and you run into a lot of those Minimatas. They have about 10 milli-equivalents of salt a day and they have enormous renin levels and they are much healthier than the investigators who go there. So, obviously, a whole bunch of renin isn’t going to kill you if combined with a real low salt diet.
LT: But you did that and the rat had high blood pressure his kidney after a while would just look like it had been run over by a tractor. Whereas, if the same rat, the same level of blood pressure, oddly enough, you fed a high-potassium diet it almost had no damage at all. Well, that was astounding to me. So we said, “We’ll just get these stroke-prone rats and let’s see what’s going on.” They didn’t die, either. I mean, there was something funny about it. They kept staying alive… You’d feed them a little bit extra salt and they are stroke-prone rats and, you know, after three-four months the hundred of them are all dead. But you feed them a high-potassium diet and the first experiment 50 out of 50 were still alive and we knew nobody would publish it. It was just too good to be true. So finally one rat died so it was 49 out of 50 and we sent it in.
LT: If you read Kempner, he was trying to ‘rest’ the kidneys with a rice food diet, which is low in protein. There is no talk of salt in his papers. He thought he was ‘resting’ the kidneys. . So Kempner didn’t know what he was doing. In other words, he was right for the wrong reason. There’s a rich guy here… who made Cargill into a giant who had malignant hypertension and they went to see Kempner and Kempner kept him alive for 30 years.
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