Secretin
Secretin was the first hormone to be identified. In 1902, William Bayliss and Ernest Starling were studying how the nervous system controls the process of digestion. It was known that the pancreas secreted digestive juices in response to the passage of food (chyme) through the pyloric sphincter into the duodenum. They discovered (by cutting all the nerves to the pancreas in their experimental animals) that this process was not, in fact, governed by the nervous system. They determined that a substance secreted by the intestinal lining stimulates the pancreas after being transported via the bloodstream. They named this intestinal secretion "secretin". Secretin was the first such "chemical messenger" identified. This type of substance is now called a hormone, a term coined by Bayliss in 1905.
Doctor Hormone
Doctor Hormone was an elderly scientist who, having discovered the secret of life itself, injected himself with a "youth hormone" which restored his body to youthful vigor. After agents from Urasia stole his formulas from his laboratory to aid in their nation's wars against its neighbors, Doctor Hormone and his granddaughter Jane traveled to the besieged nation of Novoslavia, where he used his scientific expertise to help battle the Urasian invaders, who were using the hormones to create armies of part animal/part human men. Later, Doctor Hormone was employed as a researcher for the United States Army and worked in a laboratory at Fort Knox.