Kim Robertson, age 13, of Richmond, Va., for her question:
WHAT IS INSULIN?
Insulin is .a hormone that regulates the body's use of sugar. In a normal person, insulin is produced by certain cells of the islands of Langerhans, a part of the pancreas.
When the body does not produce enough insulin, a person is unable to use or store sugar properly. This condition, caused by a lack of insulin, is called diabetes mellitus.
Doctors have been able to obtain insulin from the pancreas of sheep, pigs and oxen, and they use this to treat patients with diabetes. Although the use of insulin helps to control the disease and allows the patient to live an almost normal life, it does not cure diabetes.
Diabetic patients have to inject insulin into their bodies. If it is taken by mouth, the digestive system destroys the hormone. Therefore even children with diabetes must learn to give themselves injections.
Sometimes the pancreas produces an excessive supply of insulin and the result is a condition called hyperinsulinism. It produces symptoms opposite to those of diabetes.
If too much insulin is given to a diabetic person, his blood sugar may fall to a low level. This condition is called hypoglycemia, or insulin shock. The person in insulin shock may experience irritability, hunger, weakness, excessive perspiration, double vision and even coma.
A person in insulin shock can have his condition improved by taking carbohydrates. This may be done by giving carbohydrates by mouth, such as candy, sugar or orange juice, or by giving a glucose injection into the vein.
Several different types of insulin preparations are currently being offered by the drug companies. These preparations differ in the speed with which they act and in the amount of time the effect lasts.
Two Canadian scientists, Frederick Banting and Charles Best, discovered the use of insulin for diabetic persons in 1922.
Scientists do not know exactly how insulin acts to regulate the metabolism of carbohydrates. Carbohydrate metabolism is also affected by the secretions of other endocrine glands, including those of the pituitary, adrenal and thyroid glands.
Protamine zinc insulin is a slow acting drug preparation that was developed to reduce the number of injections a diabetic person had to take in a day. Usually only one injection of protamine zinc insulin acts slowly over a 24 hour period.
Insulin from hogs or beef pancreases, or the crystalline product, often requires anywhere from two to four injections during each day.
The amount of insulin given to a patient depends on his weight, diet and general health. The patient's diet must be carefully regulated by a doctor.
John Abel, an American chemist, prepared the first crystalline form of insulin in 1926.