Hans Walter Kosterlitz (27 April 1903 – 26 October 1996) was a British biologist, best known for his work on endorphins. Kosterlitz performed a famous experiment that he envisioned in a dream while sleeping. He stimulated a strip of guinea pig intestine electrically and was able to record the contractions with a polygraph. He then found that if you added opiates to the solution, the intestine would not contract. Opiates inhibit intestinal contraction. Those contractions were later found to resume in the presence of BOTH opiates and an antagonist such as naloxone. Later, endogenous endorphins were discovered by applying tissue (mouse brain homegenate) to the apparatus. This caused the contractions to cease. The degree to which an opiate agonist causes contractions in the guinea pig ileum is highly correlated to its potency.

He was elected a Fellow of the Royal Society in 1978.

1903 births | 1996 deaths | Fellows of the Royal Society | British Jews | Jewish scientists