Journal of the neurological sciences
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We investigated the immunohistochemical distribution of cytoskeletal proteins in smooth muscles of 15 patients with Duchenne muscular dystrophy (DMD), 8 patients with Becker muscular dystrophy (BMD), 28 patients with various neuromuscular diseases, and 2 normal controls, performing skin and muscle biopsies. Dystrophin immunostaining confirmed absent reaction in the arrector pili muscles of DMD patients, faint positive reaction in BMD patients, and strong dystrophin reaction in patients with other neuromuscular diseases and normal controls. Immunostaining of utrophin was positive with variable intensity in the arrector pili muscles in all DMD patients. ⋯ Vinculin, vimentin and desmin were expressed both in arrector pili smooth muscles and in vessel walls of patients with dystrophinopathy and other neuromuscular diseases, as well as in normal controls. Thus utrophin is normally expressed in the smooth muscle of the vessels and its expression does not vary in neuromuscular diseases. On the contrary, in the arrector pili smooth muscle utrophin is not expressed in normal controls but it is in dystrophinopathies, paralleling the findings in striated muscle, which expresses utrophin in a reciprocal manner with respect to dystrophin.