[Arrector muscle in patients with scleroderma. Histological and histo-enzymological study].

In a previous paper, we have found, at post-mortem examination of three cases of scleroderma, the oesophageal smooth muscle alterations already predicted by physiologists and reported by Treacy. These lesions mostly consist of a loss of the staining properties of the differenciated cytoplasm of the muscle cell, preceding any appearance of interstitial fibrosis. We have already reported these muscle lesions at all other levels of the digestive tract (stomach, small and large bowels), and also in the bladder muscle. In the present study, we have attempted to precise these notions in biopsies and have studied the arrector pili muscles in normal skin of 13 sclerodermic patients by means of histochemical (Regaud, Mallory, etc. ...) and enzyme stains. In all cases, we have been able to identify morphological alterations of the muscle fiber, mostly consisting in an irregular pattern of enzyme properties, especially when diaphorases, dehydrogenases and ATP ases were concerned. This work seems to confirm that the primary site of the sclerodermal lesions is situated in the smooth muscle fiber.