Tendon cells reside in an environment rich in mechanical stimuli and respond to these stimuli with a variety of activities. Whole tendon, ex vivo, responds to cyclic stretch by increasing DNA and collagen synthesis (Banes et al., 1999). Cultured epitenon and internal cells from tendon respond synergistically to cyclic tensile strain and a growth factor (Banes et al., 1995). Tendon cells stimulated by plasma membrane indentation with a micropipet propagate intercellular calcium waves to neighboring cells via gap junctions (Kenamond et al., 1997). Tendon cells subjected to equibiaxial cyclic stretching signal with a transient rise in intracellular calcium (Kenamond et al., 1998). Recently, it has been shown that connective tissue cells are responsive to fluid-induced shear stress similar to cells of the vascular system. Moreover, Brown and coworkers have shown that apparati used to apply substrate tension to cultured cells have limitations that include a potentially confounding component of fluid-induced shear stress (Brown et al., 1998). Hence, there is a concern that a given cell response to substrate stretching may actually involve a response to shear stress or some combination of the two stimuli. We have designed a parallel plate, laminar flow apparatus that provides regulated fluid-induced shear stress and subjected tendon cells to shear stresses of 0, 5, 10, 15 and 20 dynes/cm2. This will enable us to make a direct comparison between fluid-induced shear stress and substrate deformation on tendon cell signaling and downstream gene responses.