Brain over Muscle

Science Signaling  27 Jul 2010:
Vol. 3, Issue 132, pp. ec228
DOI: 10.1126/scisignal.3132ec228

Mutations in the gene encoding the Kir6.2 subunit of the adenosine triphosphate (ATP)–sensitive potassium (KATP) channel cause a specific type of neonatal diabetes in humans, known as iDEND, which is often accompanied by muscle weakness of unknown etiology. By studying mice expressing the mutant gene only in muscle or only in nerve, Clark et al. found that the motor impairments originate from inappropriate activation of the channel in the central nervous system rather than in muscle. Patients with iDEND are often treated with sulphonylurea therapies that block KATP channels in both brain and muscle, and these drugs can have adverse effects on heart muscle. Drugs with greater specificity for KATP channels in the brain may thus be a safer option.

R. H. Clark, J. S. McTaggart, R. Webster, R. Mannikko, M. Iberl, X. L. Sim, P. Rorsman, M. Glitsch, D. Beeson, F. M. Ashcroft, Muscle dysfunction caused by a KATP channel mutation in neonatal diabetes is neuronal in origin. Science 329, 458–461 (2010). [Abstract] [Full Text]