Insulin is a hormone with widespread consequences on metabolism and other body systems. Insulin effects majority of the body’s cells to take up glucose from the blood. Also the glucose in liver, muscle and fat tissue cells is taken by insulin. It then stores the glucose in form of glycogen in the liver and muscle. In the process of doing so, it discontinues the use of plump as a source of energy. If insulin lacks or its level in body is low, glucose is not taken up by majority of body cells. This is the time the body starts utilizing plump as a supply of energy. Its echelon is a fundamental metabolic management system. The status of insulin is also employed as a management sign to other body coordination. Failure in the management of insulin levels leads to diabetes mellitus.
Insulin is utilized in the field of medicine to cure some types of diabetes mellitus. A sick person with Type 1 diabetes mellitus relies on exterior insulin. This is so because the hormone is not all generated interiorly. Persons having Type 2 diabetes mellitus resist insulin. That is they possess comparatively little insulin generation. There are situations where patients with Type 2 diabetes might need insulin. This happens if other medical prescription methods don’t succeed in managing glucose level in the blood sufficiently. Insulin’s constitution differs faintly from one species of animal to another. Insulin obtained from animals differs in strength with that from human beings.
Discovery of Insulin
The discovery of insulin began sometimes back in the year 1869 by Paul Langerhans. He was a medicinal scholar in Berlin. This process began when he was learning the structure of the pancreas by the use of a microscope. He recognized some tissue tufts that were not noticed before. Such tufts were spread all through the bulk of the pancreas. The purpose of the tufts identified also called Islets of Langerhans, was not known. Later on Edouard Laguesse recommended that the clumps might generate secretions that perform a regulatory work in food metabolism.
Some years later on in 1889, Oscar Minkowski, a Polish-German physician in partnership with Joseph von Mering detached the pancreas from dog deemed fit and examined the pancreatic task in food metabolism. After a certain period of time, the pet keeper realized some flies feeding on the dog’s urine. After examining the urine, the physicians noticed that there was sugar in the dog’s urine. This created for the first time a connection between the pancreas and diabetes.
In 1901, Eugene Opie, ascertained the connection between the Islets of Langerhans and diabetes: Diabetes mellitus is initiated by damaging the islets of Langerhans and happens clumps are partly or fully damaged.
Before Opie’s task, the connection between the pancreas and diabetes was apparent. It is the precise task of the islets that was not known. The left side of insulin is a space-filling replica of the insulin monomer. It is thought to be organically energetic. On the right side is the insulin hexamer thought to be the stored form. Several efforts were made to separate the islets generated as a possible treatment. The professor of physiology, Nicolae Paulescu was the first one to segregate insulin. He called it during that time as pancrein. The thought at that time was that, the pancreas’s interior secretion which regulated sugar in the bloodstream as was known might provide a means of treating diabetes. Banting, a surgeon by training recognized that some arteries if tied off would cause atrophy of most of the pancreas. This would leave the islets of Langerhans perfect.
Mechanism of Action
Insulin plays a key role in glucose uptake ad metabolism. In this case the insulin is bound to it receptors thus inn return resulting to the activation of many proteins cascades. This process includes the synthesis of glycogen, glycolysis and also the synthesis of the fatty acids. In the human metabolism insulin plays many vital roles .it is involved in the control of the cellular intake of some compounds and in this case, glucose control in the muscles and in the adipose tissue. By controlling the level of the amino acids uptake , it is able to increase DNA replication and the synthesis of proteins ion the body.
In 1921 Banting traveled to Toronto to clarify his thought to J.J.R. Macleod, a Professor of Physiology. Macleod offered Banting to utilize his lab room to examine the notion. He also provided Banting with ten dogs to conduct test on. The technique Banting employed in the study was that of tying a string around the pancreatic duct. Examination after several weeks later, the pancreatic digestive cells were found to be dead. They were engrossed by the immune system thereby leaving numerous islets. Extract was then taken the islets to generate isletin. These are what are known as insulin. The extract was then tested on the dogs. The pancreatectomized dog was kept for a certain period of time by injecting it with the unrefined extract they had prepared.
Extraction of the pancreas in the dogs to be tested imitates diabetes and this cause an increased glucose levels in blood. It was found the pancreatectomized dog remained alive because the extracts containing isletin regulated the glucose level in blood by lowering it.
Banting and Best at the end of 1921 presented the outcome to Macleod but the professor noticed some errors in the design of the experiment. He recommended for the experiments be performed again with extra dogs and better apparatus. During that time, Banting proposed that they use foetal calf pancreas which had not developed digestive glands. The technique worked well. Purification of the extract was performed with the help of a biochemist, James Collip. Within a month, the group felt they were ready to perform a medical trial.
Insulin application in the treatment of diabetes
Diabetes present itself as a condition in which insulin interruption is pathologic. Diabetes mellitus is a condition representing hyperglycemia. There are two types of this condition .i.e. the type 1 and type 2 diabetes mellitus. Type diabetes results as a result of the destruction of the cells that are involved in the production of insulin in the pancreas. This results to a deficiency of insulin. On the other hand, type 2 diabetes mellitus results as a result of genetic susceptibility and environmental factors. These factors can be obesity, physical inactivity and age resulting in insulin opposition in cells that are in need of insulin for the absorption of glucose. The absence of insulin or low levels of insulin result to the conversion of glycogen to glucose by the liver cells to the blood. In this case the high blood glucose concentration for a diabetic patient is reduced as a result of the increased glycogen synthesis. In 1922, Leonard Thompson, diabetic was injected with the first insulin. Because the extract was not a pure one, Thompson developed a harsh allergic response. For a period of 12 days, Collip worked hard to improve the ox-pancreas extract. A second dose was injected on the 23rd which was fully successful with no side-effects. This eliminated the glycosuria sign of diabetes completely.
Rubenstein AH.(1979) .Assessment of the secreatory capacity of insulin in diabetes meellitus. Human Pathology. 10,3:257-66