A group of researchers from Oxford University, the University of Padova, and UCL have discovered that androgen receptors – common proteins found on the surface of our cells which respond to hormones – in muscles are activated by testosterone to generate more muscle tissue in response to demanding situations such as physical exercise, or loss of nerve function.

This might explain why people with higher testosterone levels tend to be more muscular​. And, it could explain how commonly abused doping agents in sport, such as anabolic steroids, have the effect they do.

Led by Carlo Rinaldi, a clinical scientist at Oxford and neurologist at Oxford University Hospitals and UCL Hospitals, the team used techniques including single molecule tracking at the CLF’s Octopus facility to show that testosterone-activated androgen receptors enable the SMAD4 protein to mount a muscle-building response in situations of increased demand.

The team found the muscle-building effect is impaired in patients with Spinal Bulbar Muscular Atrophy (SMBA). SMBA, also known as Kennedy’s Disease, is an adult-onset degenerative disease which leads to loss of muscle function and eventual paralysis, and currently has no known cure.

Read the publication in Acta Neuropathological at https://link.springer.com/article/10.1007/s00401-022-02428-1.