Helsinki: Researchers discover powerful new painkiller

Research lead

Researchers at Helsinki University, Finland, working with colleagues at the University of North Carolina, US, have discovered a powerful painkiller that to date shown no side effects in mouse testing. The enzyme, which occurs naturally in the body, alleviates pain eight times more effectively than morphine.

Pirkko Vihko of the Department of Biological and Environmental Sciences at the University of Helsinki has conducted research on prostatic acid phosphatase (PAP) an enzyme that is found in high concentrations in the prostate gland, for more than 30 years.

Last year, Vihko’s research team described the membrane-bound form of the enzyme and showed that it is present not only in the prostate, but in many other cells and organs as well.  Significantly in this context, the PAP enzyme exists in pain-sensing nerves, but has disappeared from damaged nerves.

Working with a PAP knockout mouse model Vihko, together with Mark Zylka's team from the University of North Carolina showed the mice had an increased sensitivity for pain caused by inflammation and neural damage. Replacing the PAP enzyme with a protein replacement treatment removed pain effectively and was eight times more potent than morphine. The researchers are now planning to advance the enzyme into clinical research.

The researchers have also shown that the mechanism of action involves the PAP enzyme generating adenosine, which controls pain through the adenosine receptor.