Kinetics of the sodium-dependent component of l-[35S]cysteine uptake into freshly isolated rat cardiomyocytes. Concentration dependence of the initial rate (60 s) of the sodium-dependent component of l-[35S]cysteine uptake. Three conditions are shown: total uptake (squares, dashed line); αMeAIB sensitive (portion of the total uptake that is inhibited by the addition of 10 mM αMeAIB, circles, dotted line) and αMeAIB insensitive (portion of the total uptake that is unaffected by αMeAIB addition, triangles, solid line) Least squares analysis was used to fit each data set to the Michaelis–Menten equation: Y = Vmax X/(Km + X) from which the Km and Vmax were calculated. Data shown are means ± SE of n = 4