PARALLEL EXPRESSION LEVEL OF DYSTROPHIN AND CONTRACTILE PERFORMANCES OF RAT AORTIC SMOOTH-MUSCLE

We have recently shown that the expression of dystrophin was in line w ith the conservation of contractility in primary and subcultured vascu lar smooth muscle cells (VSMC), In this report, we provide experimenta l evidence that shows the existence of a gradient in dystrophin expres sion from the aortic arch to the region just above the diaphragm, in l ine with a parallel gradient of contractility, On the contrary, there were no differences in caldesmon and smooth muscle myosin expression, as previously shown for vimentin and alpha-smooth muscle actin [Osborn , M., Caselitz, J., and Weber, K. (1981) Differentiation 20, 196-202]. Overall, this is the first demonstration, in a normal adult smooth mu scle, of a differential expression of dystrophin, in line with its con tractile performances. In addition, these results suggest that the exp erimental modulation of dystrophin expression in cultured VSMC in line with their contractility was the manifestation in vitro of an actual physiological property of those cells in vivo. (C) 1995 Academic Press , Inc.