Viper Venom

Want to know how ACE inhibitors were discovered?

Here is the story from the horses mouth, John Vane ( a genius, sadly missed).

"When the snake venom peptide was injected before the angiotensin, the blood pressure rose after angiotensin II but not after angiotensin I, as should be the case if ACE is inhibited in the body.

When Squibb applied to the U.S. Food and Drug Administration (FDA) for permission to conduct this experiment in the United States, the FDA refused since angiotensin I was not marketed in this country (although angiotensin II was). As a result, Vane arranged to have the first clinical test performed in the U.K."

http://www.fasebj.org/cgi/content/full/17/8/788