“The organ is exceptional. If one is removed, people won’t notice.”
In honor of the 300th anniversary of the Russian Academy of Sciences, which Russia will celebrate on February 8, we are starting a series of materials about science and interviews with outstanding scientists of the country who have made significant fundamental contributions to the study one or another scientific field. Our conversation today is with Academician of the Russian Academy of Sciences, Advisor to the Russian Academy of Sciences Yuri NATOCHIN, a specialist who knows everything about the physiology of the kidney and water-salt metabolism. For example, that:
—the kidney is not only an organ of excretion, but also the storage of useful substances;
— it was the kidneys that saved many in besieged Leningrad from hunger;
— life arose not in the sea, as many believe, but in a potassium reservoir.
Photo: spbu.ru
Yuri Viktorovich Natochin was born on December 6, 1932 in Kharkov. Soviet and Russian scientist, Doctor of Biological Sciences, specialist in the field of kidney physiology and water-salt metabolism, academician of the Russian Academy of Sciences. He organized the medical faculty at St. Petersburg State University, created the world-famous Russian school of kidney physiology, and proposed an alternative view of the origin of life. Last year, for his significant contribution to the research of human physiology, he won the most prestigious award of the Russian Academy of Sciences — the Great Gold Medal named after M.V. Lomonosov.
Presentation of the diploma of Honorary Doctor of the Military Medical Academy to Zh.I. Alferov (left) and Yu.V. Natochina. 2012.
— I would say that the kidney is an organ of excretion and preservation. Each of us every minute receives a quarter of all the blood that the heart supplies to the vessels. «Why so many?» — you ask, because this is many times more than what goes into the brain or heart! I’ll explain with an example… a concert. When you come to a concert and it takes a long time to start, why do you think this happens? The artists wait for complete silence. So, the kidney creates for each of us absolute physical and chemical silence — the constancy of the composition of the pericellular environment, necessary for the functioning of each cell.
After all, in order to work normally, it should not “think” whether it has glucose or not, whether it has all the necessary microelements or is missing some. She must be in a stable environment — then she will live as she likes.
How a kidney helps you understand that you are full
— Normal for a good For the body to function, the cell volume must remain constant. To do this, it is necessary to maintain normal osmotic pressure of the pericellular fluid. This is the first thing the kidney “thinks” about.
— Osmotic pressure is the concentration of all substances dissolved in one milliliter of liquid: sugar, sodium, potassium — whatever you want. Osmotic pressure contributes to what many women dream of when trying to maintain a slim figure: stopping in time when they feel full while eating. You just need to listen better to your body, and then the physiological system will tell you when to stop eating.
— The hypothalamus contains osmoreceptors that are sensitive to changes in osmotic pressure. For health, the osmotic pressure of the blood must be strictly constant. This is one of the constants of the human body. As soon as the concentration of dissolved substances increases beyond measure, the osmoreceptors react to this increase in pressure by making us thirsty. We drank water — the blood became more diluted, which means that the osmotic pressure dropped.
“You will probably be surprised, but in the event of thirst, it is they who trigger the process of saturating the blood with moisture: the hormone vasopressin is secreted from brain cells — it enters the blood, with its current reaches the kidney and forces it to absorb the missing water into the blood through the tubules.< /p>
— There is an opinion that we need to drink more… Now, everywhere you look, everyone drinks water, coffee: on buses, in the subway, as if to please some strange fashion. Was it possible 20 years ago that everyone would sit with bottles, glasses and drink?! This is a rather intimate process, just like eating. In addition, in transport you can quickly catch some kind of infection from dirty hands or contaminated bottles. In general, I am an absolute opponent of this.
—I think that this is still more the result of advertising. I had a good friend, colleague Valtin Heinz. He is the greatest American professor. I visited him and we talked about how much to drink. Both agreed that the previous recommended levels from the mid-60s and 70s — about 1.5 liters of fluid per day — were more acceptable.
— It could be less. The kidneys are designed in such a way that 0.8 liters may be enough for you. I’m now talking about healthy people whose osmoreceptors work well, signaling when it’s time to regulate osmotic pressure.
—Nothing bad happens to them either: the kidneys cope, because their absolute potential — 25 liters per day. There are other problems: harm comes from drinking too much coffee, which can cause your blood pressure to jump, or from dirty hands, as I already said.
— There are, for example, diseases in which a person experiences extreme thirst all the time, and they drink up to 25 liters of water a day.
— The second most important purpose of the kidney is to regulate the volume of blood in the body. Imagine that you bought red caviar and ate a lot of it. A large amount of salt increased the osmotic pressure. What are you doing? You drink a lot, which increases the volume of fluid in the body. Now it has already equalized the osmotic pressure, but excess liquid has appeared, which the osmotic receptors no longer sense. This is where volume receptors turn on, which control the degree of vascular stretching. All this turned out to be very important. Once I was approached by specialists from the Institute of Medical and Biological Problems of the Russian Academy of Sciences, who care about the health of astronauts. In particular, they are worried about their adaptation upon returning to Earth, because those who flew in the early years were carried on stretchers after landing…
It was 1964, I examined the crew of the Voskhod-1 ship — Vladimir Komarov, Konstantin Feoktistov and Boris Egorov, and as a result of this examination it occurred to me how to stop the negative picture.
< p>— This is true, but osmo- and volume regulation plays an equally important role. Any person, if he flies into space, is faced with a radical redistribution of fluid in the upper part of the body.
The task before me was to turn it around, to prepare the astronauts’ bodies for landing. Above I mentioned the receptor that “senses” excess fluid. So, it was necessary to create conditions so that he would “tell” the kidneys: “Take away this excess fluid!” It took 10 years to get permission to conduct the experiment, and in 1974 we carried it out. I received an order for this.
— I simply suggested giving the astronauts a salt tablet once before landing in order to restore the salt deficiency and water-salt balance and prepare for the earthly norm.
— The space environment was largely incomprehensible. Who knew how the human body would react to a sharp increase in salt levels? In theory, we could have eaten the salted ram before landing, but we had to calculate everything accurately.
Yuri Natochin at the mission control center, NASA, 1973.
As a result, having established osmoregulation and volumetric regulation, we ensured that the astronauts, upon returning to Earth, immediately stood up and walked.
“Few people know that the kidneys produce hormones that keep our blood pressure constant. Another hormone that is produced in the kidney is the hormone that regulates blood clotting; glucose is also synthesized here. Recently, another important function of this important organ was established — participation in the regulation of calcium balance.
The kidney constantly maintains the concentration of every element of the periodic table, every ion that is needed for the functioning of organs. Neither the liver nor any other organ has such functions. Maybe I will surprise you, but did you know that it is the kidneys that ensure the maximum possible preservation of health and life during fasting?
— The kidney digests the changed protein! This is the main organ for converting modified, “broken” proteins into amino acids. These proteins are no longer able to perform their physiological functions and therefore do not remain in the blood as healthy ones, but enter the kidney tubules during filtration. So, the kidney breaks them down into amino acids and returns them to the blood. Giving them a second life, and at the same time supporting a person, it participates in preserving the brain and heart during fasting. Surely the kidneys extended the lives of many Leningraders during the siege…
— Several years ago, the International Union of Physiological Sciences created a special Commission on the Physiology of the Kidney so that we could speak the same language when studying this organ. I was invited to join this commission, and we developed a nomenclature for kidney structures. It has been published in four of the world's most renowned physiological scientific journals. So, there you could read that each of the two million nephrons (structural units of the kidneys) consists of 12 (!) parts.
Yu.V. Natochin conducts an experiment with the administration of vasopressin to a dog, 1954 < /span>
At one time, people thought that they would be able to create a full-fledged artificial kidney. But it turns out that this is impossible to do, because there is such a variety of functions and such a precise fit — only the Lord God could do this! Now — the principle of operation: the kidney has two parts — the glomerulus and the tubule. Everything that is needed is taken from the tubule fluid, and the rest is released out. The glomerulus filters fluid. Each substance separately must be “palpated” by the kidney and the necessary one returned to the blood.
More than a ton of blood passes through the kidneys per day, and from this amount all useful substances must be returned after filtration!
When I lecture to students, I say that all this reminds me of the Odyssey. Remember, when the Cyclops Polyphemus was left without an eye, he began to check each lamb: is it walking alone or someone else is riding on it. The kidney does the same: it “feels” every substance.
— The kidneys are an exceptional organ. If one is removed, people won’t notice. If you remove half of the next one, then you won't be able to do hard work. That's all. And nature also provided: if a kidney is removed, then the second one is ready to compensate for the deficiency within 2-3 days, and immediately by 80%.
— Experts once made a very good artificial kidney and thought that it would save the sick. But patients who were admitted for hemodialysis lived up to 4 years and died. They did not die because the kidney did not cope well with excretion: it lacked all those additional functions I listed above. The artificial kidney does not digest proteins and does not regulate blood pressure; fish oil — even that without a kidney is useless, because it is from it that a molecule is synthesized in the kidney to regulate calcium balance.
But it still cannot be said that science is marking time: having understood what was the matter, scientists began to develop methods of hemodialysis in which people, using modern artificial kidneys, can live a long time.
“Fish’s blood is not as salty as in the sea, but there is no one to give them, the poor, a glass of fresh water.” What's the trick? And the fact is that all marine bony fish known to us, for example, cod, desalinate water in their gills, the cells of which secrete salts.
Study of water-salt metabolism in marine animals: Yu.V. Natochin together with Doctor of Sciences V.Ya. Berger at the White Sea Biological Station of the Academy of Sciences, 1982.
By the way, when I took up the issue of fish physiology, I understood why the Russian sturgeon is called Russian. It turned out that there are no more fish with such osmoregulation as his: the salinity of their blood is the same as the water in the Caspian Sea or the Sea of Azov. This is their main feature. These fish do not spend energy on osmoregulation, like, for example, their Black Sea or Mediterranean relatives. The blood of Russian sturgeons is close in osmotic pressure to the water of the Middle Caspian.
And in the early 70s, the Caspian Sea began to become shallow, and in connection with this, a program was conceived to replenish the water by transferring Black Sea waters to it. We began to sound the alarm: “Stop this project, otherwise we will destroy the Russian sturgeon herd.” Fortunately, they listened to us.
— Who said they don’t drink? All birds flying over the ocean land on the water and drink salt water. They have salt glands in their nose and in the corners of their eyes. These glands secrete salt and thus desalinate the blood to normal.
—In 2005, I suggested , different from the generally accepted concept. According to him, the environment for the emergence of the first cells was water bodies with a predominance of potassium ions, and not sea water with a predominance of sodium ions.
Take any cell. In the center it has a core, in the liquid around it there is a high concentration of potassium, and on the outside, if we accept the version of the origin of life in the sea, sodium ions predominate. Bioelectric processes must arise between them for further development.
But the fact of the matter is that in order to maintain the concentration of potassium ions in the cell, in the membrane of those cells there was then no so-called potassium-sodium pump, which would take potassium from the external environment and drive it into the cell. At the dawn of the evolution of life, such a pump did not exist.
The only solution, I guessed, may be the same salt composition of the reservoir as the internal composition of the first cell, which is most suitable for protein synthesis. So the question arose: could potassium lakes exist on the early Earth?
I had a good relationship with academician geochemist Erik Mikhailovich Galimov. I told him about my idea — he hired two employees, and they began to investigate whether during the evolution of the Earth there were potassium lakes at first. And what do you think? They found and proved that they were. We then published the corresponding article in the magazine. Then we conducted research with academician Mikhail Vladimirovich Dubina and substantiated a new hypothesis about the origin of life. It was published in the journal Origin of life.
— My secret is simple: I try to live in harmony with my kidneys and other organs. My daily routine is extremely simple: I eat and drink exactly as much as I want. For example, in the morning I drink coffee, capsule. By the way, now in Russia they have learned to make their own capsules, which are quite acceptable.
—No. But this is just a taste preference.
— Milk is not harmful. I eat dairy products every day when I get home from college. You know, we don’t have a canteen there, and I don’t carry sandwiches.
— Ideally, I would have lunch, but I’m already used to this routine.
— Nothing on purpose, except maybe a lot of sugar. I can drink cognac, vodka, and wine — whatever you want. But if before I could drink more, now I can drink much less. I like good wine or cognac, which I drink in small glasses, mainly to feel their bouquet.
Natochin with students and teachers of the medical faculty, 2004;
At home I don’t cook the first thing, I make do with yoghurts. I love greens, cauliflower, zucchini, and eat less potatoes. For meat, I prefer chicken legs, which I boil well for at least 50 minutes. After that I drink tea, before going to bed I can drink a cup of cocoa.
— I like fresh bread with butter or sour cream — not 15 percent, but richer… I actually decided for myself, and something tells me that this is right: eat what the body wants. He knows what's missing. This unspoken rule turns into a kind of appetite for me — I buy what I want.
— I used to pour in half a glass of sugar… Now I’ve cooled down on it a little — like when I take tests, I see that the sugar has become higher. I always loved the liquid chocolate that my mother prepared for my birthday. By the way, I still don’t deny myself good chocolate to this day. At the same time, I am not overweight; I wear a suit of the same size that I wore while studying at the institute.
Physical activity is very important for good health. I remember when I was still a student we went to a collective farm for an internship. No one there wanted to transport grain from the combine on a cart. I took over and took grain to the elevator every day. And in the evening I unharnessed the horse, sat on horseback (by that time I had learned to ride without a saddle) and galloped around the villages…
I still maintain an active lifestyle: I always go to and from work only on foot. I do everything around the house myself: I have been living alone for more than 15 years after the death of my wife.
— Of course, I am concerned about the fate of the academy. Three centuries ago, Peter conceived the correct system of organizing science. The country needed scientists who would find ways to increase the country's prestige. And as for funding, everything was extremely simple: researchers were allocated enough to have enough for food, shelter, travel, and to solve problems necessary for society.
We now allocate grants for certain topics. But the same Academy of Sciences of the USSR would not have been able to achieve exceptional success, and the country would not have been able to win the Second World War, if its scientists did not have freedom of creativity. Therefore, I would wish our science to remain strong and worthy in the knowledge of the laws of nature and society and to make our state strong.
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