Scientists Identify 2 Chemicals in Brain That Affect Pain Process

From Times staff and wire reports

U.S. researchers reported Wednesday that they have identified two brain chemicals that strongly affect pain processes in the brain and said they could be the key to how drugs like morphine and heroin work.

Another expert said the two peptides could possibly even be used as nonaddicting painkillers.

James Zadina and colleagues of the Veterans Affairs Medical Center and Tulane University in New Orleans named the peptides endomorphin-1 and endomorphin-2 and said they acted by themselves to ease pain in mice.

Writing in the journal Nature, they said opiates such as morphine were known to act on brain cell receptors--a kind of keyhole--known as mu receptors. But no one had found the key, or ligand, that hooks the opiates to the mu receptor.