Our body is perfectly coordinated to regulate our blood sugar level. But when our insulin levels are artificially altered, serious diseases can occur.

The human body needs energy. ATP (Adenosine Triphosphate) is to each cell in the body what gasoline is to a car. This energy is stored inside the bonds of the three phosphate molecules attached to an adenosine nucleotide. The light energy that exists in the sun’s rays is converted into chemical energy, stored in the form of carbohydrates, proteins, and fats through the photosynthetic reactions taking place in the chloroplasts of plants. Molecules of chemical energy are broken down in the mitochondria organelle of the cells in order to utilize their energy for ATP synthesis. This chemical energy (ATP) derived from nutrients is used by the eyes to see, the ears to hear, the hands to grab, the feet to walk, the heart to pump blood, the stomach to digest foods, the kidneys to filter blood, red blood cells to carry oxygen, white blood cells to fight germs, and the brain to think, memorize, and remember.

ATP is primarily synthesized from glucose – commonly known as blood sugar (glycolysis) – in approximately 100 trillion cells in our body. Glucose means fast energy. A sensitive metabolic balance is established (homeostasis) to maintain a blood glucose concentration in between 70-100 mg/dl for a nonstop energy flow and to prevent any cellular damage. If this balance is thrown out of order, many medical problems will ensue, primarily cardio-vascular diseases. How is the homeostatic balance of blood sugar maintained in healthy people?

Maintenance of blood sugar balance

The blood sugar balance is provided by the assistance and cooperation of the pancreas, liver, fat tissue, muscle tissue, the brain, the digestive system, and the kidneys. The chiefs of the orchestra here are the insulin and glucagon hormones synthesized in the pancreas, which operate in great harmony and yet have opposite functions. Insulin is in charge of dropping blood sugar; however glucagon increases it.  

The fine balance of blood sugar is conserved before we sense it for various energy situations such as exercise, sleep, or various energy intake cases such as overeating or skipping a meal. The real hunger is the 8-10 hour long “night fasting” period. During this time, since there is no food intake, the glucose that cells require for energy production is obtained from reserves in the liver. Thus, cells get their energy and blood sugar levels are kept at normal levels. If there is no additional food intake and the fasting time becomes longer, the glycogen reserves of the liver get consumed within 10-18 hours and necessary energy is obtained from fats and proteins. However, real fullness corresponds to a period of 4-6 hours “after meal.” During this time, the complex and macro size carbohydrates are converted to glucose in the liver and this glucose is stored as glycogen. Because the glucose storage capacity of the liver, which has numerous tasks, is limited, the excess glucose is stored by conversion into fatty acids. The unspent excess calories from three meals eaten in five hour intervals will be stored in either the liver or as fat tissue during the 12-18 hour long fullness period. The utilization of fats stored in the humps of camels which form by food intake to compensate for their energy and water needs during long desert travel can be given as an example of this.

In fact, when we say “I am hungry,” we acknowledge that the time has come to resupply our ATP reserves of nearly 100 trillion cells. The most important stimulator for the secretion of insulin from the pancreas is glucose. With the first bite, the readied insulin reserves of the pancreas are released into the bloodstream. This event, which takes place approximately within the first 6-10 minutes, is called the first-phase insulin response. With the language of reduced glucagon as a result of increased insulin, the message that it is no longer necessary to release glucose into the blood is transmitted to the liver. The blood sugar levels increase with continuing food intake (hyperglycemia) and this information is relayed to the pancreas through hormones secreted by intestinal cells. As directed by this signal, the proper insulin amount necessary for blood sugar levels is secreted into the bloodstream from the pancreas. This is called the late-phase insulin response.

The tasks of insulin

Cells are in need of insulin to uptake glucose into capillary vessels. Insulin binds itself to its specific receptor on the membrane of a cell, conducting its message, especially to muscle tissue. It’s saying, “The glucose food that you need is brought here by the blood vessels, and you can retrieve it.” After receiving the message inside the cell, GLUT (glucose transporters) molecules, which are in charge of glucose intake and are stored in the cytoplasmic vesicle pool, are carried to the cellular surface. Molecular gates are established once these molecules merge with the cellular membrane for the entrance of glucose through it. Glucose is inserted into the cell via this gate. The retired GLUTs are collected back in the cytoplasmic pools after cellular energy demand is met.

While these events are taking place, commands are given to the liver to prepare for the load of glucose arriving from the intestines and for adipose tissue to store the excess fat. These meticulous processes last for approximately two hours. The blood sugar level recedes back to its normal limits, but the activities of the liver and the adipose tissue continue at a rapid pace. If overeating occurs, the liver cannot take such a load. This can cause a delay in its functions, which will cause the body to feel tired.

The insulin and glucagon hormones have a half life of 3-5 minutes and are rendered ineffective in the liver and kidneys once they conclude their tasks. Thus, the body prevents lower blood sugar levels because of high insulin concentrations (hypoglycemia) or because of higher glucagon levels; it also prevents higher blood sugar levels (hyperglycemia).

The disruption of the blood sugar balance

Diabetes is the chronic observation of blood sugar above normal limits. This happens when the insulin hormone levels secreted from the pancreas are reduced and not able to carry out their function. There might be genetic factors present that contribute to diabetes; however, stress, a lack of exercise, obesity, and the consumption of processed foods containing elevated levels of carbohydrates often lead to the onset of diabetes in adults. The fine balance in between the liver, pancreas, muscles, and fat tissue can be disrupted by the following reasons:

1. If the number of cells in charge of insulin production in the pancreas decreases, sufficient insulin cannot be produced.
2. The message of insulin cannot be retrieved completely because of a disruption occurring at the receptors where insulin binds on cells, or due to lower numbers.
3. There may be a problem with reactions regarding GLUT production in accordance with the internal message retrieved upon bondage of insulin to the receptors.
4. During fullness, if the necessary suppression of glucagon production in pancreatic cells is not adequate, the glucose release from the liver continues.
5. The secretion of late-phase insulin response hormones in charge of pancreatic stimulation from the intestines is reduced.
6. Emptiness of the stomach is delayed, and a longer absorption time of nutrients occurs.
7. The appetite center is over stimulated and the urge to eat increases.

If the reasons above take place, then the blood sugar level is above normal. Normal blood sugar drops below 140 mg/dl two hours after a meal in healthy people, whereas this cannot be maintained in diabetic patients.

An iron pipe with salty sea water running through it for years is similar to a capillary vessel that has blood with high sugar levels inside it in terms of the damage that they undergo. Once hypertension and cholesterol joins diabetes, the heart, eyes, and kidneys will not function properly. These organs are great blessings granted to our body which we often appreciate only once we lose them. Therefore we must follow an intermediate path in eating and drinking, just as in every situation, avoiding excess.

I hang between your stomach and your duodenum under it, attached to the intestinal mesenteries. I have two different identities in terms of my structure and function. I carry out two very different duties as a compound gland made up of both exocrine and endocrine tissues. So, I am granted a very special structure and chemical abilities to function well. One of my duties is related to the physiology of digestion: I break up the food passing from the stomach to the duodenum by pouring on it the four types of digestive enzymes I have been enabled to produce. These juices are carried through a tiny pipe to your duodenum. Two of them are used for breaking up proteins, one for carbohydrates, and one for fats. You don’t even realize it! As the food you take in passes from the stomach to the duodenum, my enzymes begin flowing faster. This is a very fine balance: while food is being digested, neither the enzymes should be wasted, nor should your intestinal walls be harmed. I don’t control the release of the enzymes. That duty is given to two hormones produced in your intestinal mucosa by the stimulus of the vagus nerve. When those hormones reach me by the bloodstream, my cells are stimulated and they secrete water, bicarbonate, and the digestive enzymes I mentioned and they flow into your duodenum through my duct.

My second job is the production of insulin and glucagon hormones, as the endocrinal pancreas. My cell clusters, which are also known as islets of Langerhans, have different types as separate groups, which you call alpha and beta. The insulin, which is produced by my beta cells, is used for regulating the glucose level in your blood. The duty of insulin is to stimulate your body cells to take the glucose in your blood and use it.

After you have a meal, the carbohydrates in it are broken down into glucose molecules, pass into the blood, and increase your blood sugar. For your body to function in a healthy way, the amount of glucose should be around 100mg/ml (it varies from 80–120). When the level is above the normal value, I secrete insulin. In this way, the sugar is carried to your cells and burned to produce energy, and its increase in your blood is brought back under control. Also, insulin helps you to store sugar in fat tissues and to turn them into fatty acids, and it slows the breaking down of fatty acids. Moreover, insulin helps you to make protein in your body by holding amino acids within your muscle tissues and storing glucose in your liver and turning it into glycogen.

The failure of my beta cells to secrete insulin is a serious problem; the consequence is “diabetus mellitus,” or what we commonly know as diabetes. A person with this disorder must abstain from various delicious foods and drinks. In cases where a strict diet does not solve the problem, patients may have to take insulin shots every day. Diabetes can cause many complications by damaging your nerves and blood vessels; I won’t go into types of diabetes so I don’t get sidetracked too much. I just wished to make a point: even a substance produced by a tiny cluster of cells can upset the functioning of many of your mechanisms. After having a meal, put your hand to the left of your abdomen below the stomach and remember what a blessing I am!

As for the glucagon hormone I secrete from my alpha cells, it does just the opposite of insulin and causes the sugar stored in your cells to be released into your bloodstream. When your blood sugar decreases-due to hunger, overwork, exercise, and so on-it causes the glycogen in your liver to be used in order to increase the level of your blood sugar. As adrenalin secreted by the adrenal glands helps glycogen to be broken down and to be released into the blood as glucose, they function as an integrated system. Glucagon also slows down the synthesis of glycogen, and it accelerates the break-up of proteins and fat metabolism. I think now you get it, Peter. Insulin and glycagon are parts of a biological feedback mechanism controlling one another. People discovered all these facts after years of lab research; now do you see how ridiculous it is to see me as a work of blind chance?

Like any other organ, I can also contract various diseases. The most common ones are acute or chronic inflammation, tumors, and cysts. I am easily troubled with inflammation in people with alcohol habits. Since enzyme secretions-and therefore digestive processes-are then not carried out properly, some undigested fats and fibers with proteins are excreted with the feces. A problem can arise with the intestines due to digestive deficiency. And if I completely fail to fulfill my duty owing to a chronic inflammation or tumor, then doctors take me out and you become dependent on insulin and a special liquid obtained from the pancreas.

It is sad to say that my cancer is not quickly recognized. It develops very fast and I try to keep up my duty as long as possible. Therefore, it is usually too late when diagnosed. There is nothing much modern medicine can do after it spreads. Although it is not definite yet, I suspect cigarettes play a role in my cancer.

As for diabetes, even though a promising method of treatment has been discovered, certain problems haven’t been overcome yet. The transplant of beta cells from the pancreas of someone who has just died-with as much tissue compatibility as possible-has had partial success. As with every other organ transplant, tissue rejection is a challenge. If the human genome project succeeds and the genetic code of the human body is thoroughly solved, it may be possible to cure diabetes by genetic engineering techniques. This is only at research level for now, but if scientists do their best, it is possible to find a way, since there is a treatment for every disease except for old age and death. You see Peter, as the vicegerents on earth, you humans are supposed to explore the secrets of the universe and appreciate the beauties you discover. I think I have said enough now. Thanks for listening, Peter!

Irfan Yilmaz is a professor of biology at Dokuz Eylul University, Izmir, Turkey.

I am sure, to most of us who have learned about scientists as unapproachable figures sitting on top of Mount Everest (and somehow almost all of whom are Western), this viewpoint may seem quite new. Yet, there is more to it. The same thinker points to another equally important factor in the development of civilization and advancement of sciences: with a great strength in his weakness and potency in his impotence, man is very much like a pampered child in creation. If he recognizes his weakness and performs his worship with his words, actions and state of mind, if he knows his own impotence and asks for God’s aid, he will then have fulfilled the obligation of gratitude for the subjugation of creation to his needs.

As with a petted child who by means of a little cry or simply a sad look obtains the assistance of adults to serve him: even the tiniest part of what they do for him by far exceeds what lies in the child’s own power to do for himself, and their great help he owes to his great weakness. So too, the apparent dominance of man over the rest of creation and his progress in civilization are not the result of his own deserving but they were subjugated to him because he himself was weak: he received aid because he was helpless; he was enriched thereby because he was poor; he was inspired because he was ignorant; he was bestowed with favours because he was in need of them (Nursi, 23rd Word). 

Penicillin

Most people believe that great discoveries are results of deliberate, directed effort, planning. exhaustive experiment and logical inference. The discovery of penicillin is the most famous counter example. Although the role of planning, experimenting and research has an undeniable role in scientific discoveries, events do not always form a logical sequence, and this is what I am here trying to emphasize.

During World War I, doctors depended on antiseptics to cure battIe wounds. A. Fleming, a bacteriologist, observed that phenol (or carbolic acid, the most common antiseptic at that time) did more harm than good, in that it killed the leukocytes (white blood cells) faster than it killed the bacteria, and he knew this was bad because the leukocytes are the body’s natural defenders against bacteria.

In 1922, while suffering from a cold, Fleming made a culture from some of his own nasal secretions. As he examined the culture dish filled with yellow bacteria, a tear fell into it from his eye. The next day, when he examined the culture, he found a clear space where the tear had fallen. He correctly concluded that the tear contained a substance that caused rapid destruction of the bacteria, but was harmless to human tissue. The antibiotic enzyme in the tear he named lysozyme. It turned out to be of little practical importance because the germs that lysozyme killed were relatively harmless, but this discovery was an essential prelude to that of penicillin.

In the summer of 1928, Fleming was engaged in research on influenza. While doing some routine laboratory work involving microscopic examination of cultures of bacteria grown in petri dishes (flat glass dishes provided with covers), Fleming noticed in one dish an unusual clear area. Examination showed that the clear area surrounded a spot where a bit of mould had fallen into the dish, apparently while the dish was uncovered. Remembering his experience with lysozyme, Fleming concluded that the mould was producing something that was deadly to the staphylococcus in the culture dish. Later he would say: ‘There are thousands of different moulds and there are thousands of different bacteria, and that chance putting the mould in the right spot at the right time was like winning the Irish sweep.’

Fleming’s own words are enough as a response to those who attribute scientific discoveries to chance or idolize scientists. However, I will give other examples to make the point clearer.

Teflon

From non-stick frying pans to space suits to artificial heart valves, Teflon has found several areas of application. Its discovery resulted from an apparently ‘accidental’ observation by a young chemist, R. Plunket, working in Du Pont laboratories. On April 6, 1938, Plunket opened a tank of gaseous tetrafluoerothylene in the hope of preparing a non-toxic refrigerant from it, but no gas came out, to the surprise of Plunkett and his assistant. Plunkett could not understand this because the weight of the tank indicated that it should be full of the gaseous fluorocarbon.

Instead of discarding the tank and getting another in order to get on with his refrigerant research, Plunkett decided to satisfy his curiosity about the ‘empty tank’. Having determined that the valve was not faulty by running a wire through its opening, he sawed the tank open and looked inside. There he found a waxy white powder and, being a chemist, he realized what it must mean.

The molecules of the gaseous tetrafluoroethylene had combined with one another ‘polymerized’ to such an extent that they now formed a solid material. The waxy white powder did indeed have remarkable properties: it was more inert than sand – not affected by strong acids, bases or heat and no solvent could dissolve it – but, in contrast to sand, it was extremely slippery.

X (Roentgen) Rays

Physicist W. Roentgen discovered the rays which were later to be named after him, in an unexpected and unplanned manner. Roentgen was repeating experiments by other physicists in which electricity at high voltage was discharged through air or other gases in a partially evacuated glass tube. We now know that cathode rays are actually streams of electrons being emitted from the cathode, and the impact of these electrons on the walls of the glass tubes produces the phosphorescence.

In 1892, it was demonstrated that cathode rays could penetrate thin metallic foils. Discharge tubes having thin aluminium windows allowed the cathode rays to pass out of the tube where they could be detected by the light they produced on a screen of phosphorescent material (such screens were also used to detect ultraviolet light), but they were found to travel only two or three centimetres in the air at ordinary pressure outside the evacuated tube.

Roentgen repeated some of these experiments to familiarize himself with the techniques. He then decided to see whether he could detect cathode rays issuing from an evacuated all-glass tube, that is, one with no thin aliminium window. Na one had observed cathode rays under these conditions. Roentgen thought the reason for the failure might be that strong phosphorescence of the cathode tube obscured the weak fluorescence of the detecting screen. To test this theory, he devised a black cardboard cover for the cathode tube. To determine the effectiveness of the shield, he then darkened the room and turned on the high voltage coil to energize the tube. Satisfied that his black shield did indeed cover the tube and allowed no phosphorescent light to escape, he was about to shut off the coil and turn on the room lights so that he could position the phosphorescent screen at varying short distances from the vacuum tube:

Just at that moment, he noticed a weak light shimmering from a point in the dark room more than a yard from the vacuum tube. At first, he thought there must be, after all, a light leak from the black mask around the tube, which was being reflected from a mirror in the room. However, there was no mirror. When he passed another series of charges through the cathode tube, he saw the light appear in the same location again, looking like faint green clouds moving in synchronism with the fluctuating discharges of the cathode tube. Hurriedly lighting a match, Roentgen found to his amazement that the source of the mysterious light was the little fluorescent screen that he had planned to use as a detector near the blinded cathode tube, but it was lying on the bench more than a yard from the tube.

Roentgen realized immediately that he had encountered an entirely new phenomenon. These were not cathode rays that lit up the fluorescent screen more than a yard from the tube! With feverish activity, he devoted himself single-mindedly in the next several weeks to exploring this new form of radiation. He reported his findings in a paper published in Wunburg, dated December 28, 1895, and entitled ‘A New Kind of Ray, a Preliminary Communication’. Although he described accurately most of the basic qualitative properties of the new rays in this paper, his acknowledgement that he did not yet fully understand them was indicated by the name he chose for them, X-rays. (They have also often been called Roentgen rays.)

He reported that the new rays were not affected by a magnet, as cathode rays were known to be. Not only would they penetrate more than a yard of air, in contrast to the two or three inch limit of cathode rays, but also (to quote his paper):

‘All bodies are transparent to this agent, though in very different degrees. Paper is very transparent; behind a bound book of about one thousand pages I saw the fluorescent screen light up brightly. In the same way the fluorescence appeared behind a double pack of cards. Thick blocks of wood are also transparent, pine boards two or three centimetres thick absorbing only slightly. A plate of aluminium about fifteen millimetres thick, though it enfeebled the action seriously, did not cause the fluorescence to disappear entirely. If the hand be held between the discharge tube and the screen, the darker shadow of the bones is seen within the slightly dark shadow image of the hand itself.’

He found that he could even record such skeletal images on photographic film. This property of X-rays captured the attention of the medical world immediately. In an incredibly short time X-rays were used routinely for diagnosis in hospitals throughout the world.

Insulin

If a relative or a friend of yours has diabetes, you will probably know how important insulin is for them. As a partial remedy for most diabetics today, insulin was discovered as an answer to the prayers of hundreds of thousands of diabetics by the Most Merciful One. Perhaps, even better relief and remedy are awaiting discovery in some unexpected time or place.

In 1889, while studying the function of the pancreas in digestion, two researchers removed the pancreas from a dog. The very next day a laboratory assistant called their attention to a swarm of flies around the urine from this dog. Curious about why the flies were attracted to the urine, they analysed it and found it was loaded with sugar. Sugar in urine is a common sign of diabetes.

The researchers realized that they were seeing for the first time evidence of the experimental production of diabetes in an animal. The fact that this animal had no pancreas suggested a relationship between that organ and diabetes. The researchers subsequently proved that the pancreas produces a secretion that controls the use of sugar, and that lack of this secretion causes defects in sugar metabolism then exhibited as symptoms of diabetes.

Many attempts were made to isolate the secretion, with little success until 1921. A young Canadian medical student extracted the secretion from the pancreas of dogs. When they injected the extracts into dogs rendered diabetic by removal of their pancreases, the blood sugar levels of these dogs returned to normal or below, and the urine became sugar-free. The general condition of the dogs also improved.

Until recently, all insulin used for the treatment of human diabetes came from the pancreases of some animals. As a result of genetic engineering, based on knowing how DNA controls protein synthesis, a major pharmaceutical firm has begun to produce human insulin by using bacteria. The fact that a microscopic creature, like the bacterium can be made to work for the wellbeing of human beings is a subject worthy of study on its own.

Of course, these are by no means the only examples worth mentioning of ‘happy, chance discoveries’. Here are some more to add to the list: the discovery of molecular structure of organic compounds, saccharin and nutra-sweet (sugar substitutes, again for diabetics), ‘safety glass used in automobiles and planes, oxygen and several other chemical elements, radioactivity, astronomical discoveries like pulsars and background Big Bang radiation, many mathematical theorems, high temperature superconductors, synthetic dyes, etc., etc.

Can one really call all of these marvellous discoveries simply ‘happy, chance accidents’? I believe human conscience and reason must resist such a misconception. Surely, any person of common sense would say: ‘I am thankful to the Merciful One, who has bestowed upon us the favour of these discoveries, enabled us to benefit from them, among His innumerable other bounties’.