How can insulin be produced

In , Keen et al. No adverse reactions to cutaneous, subcutaneous or intravenous administration of the synthetic insulin were identified.

Furthermore, the synthetic insulin depressed blood glucose levels to a similar degree and with a similar trajectory to highly purified porcine insulin. These positive results indicated that synthetic insulin could provide a viable alternative to animal insulin and in synthetic insulin became the first genetically engineered product to be approved by the FDA.

Despite the novelty of the product, review and approval took just 5 months, at a time when the average approval time for new drugs was more than 2 years. From , the original method was replaced with one that used a plasmid containing the gene for human proinsulin.

Evidence soon indicated that the new synthetic human insulin was indeed less immunogenic than animal-derived insulin. In , Fineberg et al. Participants treated with synthetic human insulin had lower levels of insulin antibodies in blood than participants treated with porcine insulin.

The generation of fully synthetic human insulin was a major step forwards in the diabetes field and an important breakthrough in medical biotechnology, paving the way for the FDA approval of many more therapeutic recombinant proteins — more than to date. Itakura, K. Expression in Escherichia coli of a chemically synthesized gene for the hormone somatostatin.

Science , — Crea, R. Chemical synthesis of genes for human insulin. Natl Acad. USA 75 , — Johnson, I. So how did this wonderful breakthrough blossom? In , two German researchers, Oskar Minkowski and Joseph von Mering, found that when the pancreas gland was removed from dogs, the animals developed symptoms of diabetes and died soon afterward.

Later experimenters narrowed this search to the islets of Langerhans a fancy name for clusters of specialized cells in the pancreas. In , Sir Edward Albert Sharpey-Shafer suggested only one chemical was missing from the pancreas in people with diabetes. So what happened next? Something truly miraculous. With this murky concoction, Banting and Best kept another dog with severe diabetes alive for 70 days—the dog died only when there was no more extract.

With this success, the researchers, along with the help of colleagues J. Collip and John Macleod, went a step further. The body mounts an initial 'fight back' response to hypoglycaemia through a specialised set of of nerves called the sympathetic nervous system.

This causes palpitations, sweating, hunger, anxiety, tremor and pale complexion that usually warn the person about the low blood glucose level so this can be treated. However, if the initial blood glucose level is too low or if it is not treated promptly and continues to drop, the brain will be affected too because it depends almost entirely on glucose as a source of energy to function properly.

This can cause dizziness, confusion, fits and even coma in severe cases. Some drugs used for people with type 2 diabetes , including sulphonylureas e.

The body responds in the same way as if excess insulin has been given by injection. Furthermore, there is a rare tumour called an insulinoma that occurs with an incidence of per million population.

It is a tumour of the beta cells in the pancreas. Patients with this type of tumour present with symptoms of hypoglycaemia. People with diabetes have problems either making insulin, how that insulin works or both. The main two types of diabetes are type 1 and type 2 diabetes, although there are other more uncommon types. People with type 1 diabetes produce very little or no insulin at all. This condition is caused when the beta cells that make insulin have been destroyed by antibodies these are usually substances released by the body to fight against infections , hence they are unable to produce insulin.

With too little insulin, the body can no longer move glucose from the blood into the cells, causing high blood glucose levels. If the glucose level is high enough, excess glucose spills into the urine. This drags extra water into the urine causing more frequent urination and thirst. This leads to dehydration , which can cause confusion. In addition, with too little insulin, the cells cannot take in glucose for energy and other sources of energy such as fat and muscle are needed to provide this energy.

This makes the body tired and can cause weight loss. If this continues, patients can become very ill. This is because the body attempts to make new energy from fat and causes acids to be produced as waste products. Ultimately, this can lead to coma and death if medical attention is not sought. People with type 1 diabetes will need to inject insulin in order to survive.