To investigate whether the lack of dystrophin affects local cyclic nucleotide signals in the heart, we compared local cGMP and cAMP levels in cardiac myocytes from control mice (C57BL/10ScSnJ) and the mdx model (C57BL/10ScSn-Dmd < mdx > /J) which, as in human DMD, lacks dystrophin [21]. Here, DMD is linked to Duchenne muscular dystrophy.