Analysis of the NO response curves in response to shear stress changes. Experiments started at a low shear stress of 0.1 dyn/cm^{2}, which was then increased by a step change to 1, 6, 10, or 20 dyn/cm^{2}. A) Changes in the steady-state value were calculated based on the difference between the steady-state concentrations before and after a step change. The steady state change at 20 dyn/cm^{2} was statistically different from both the change observed in response to 6 or 10 dyn/cm^{2} but was not statistically significant between 6 and 10 dyn/cm^{2}. The steady-state change from 0.1 to 1 dyn/cm^{2} was statistically different from step changes to all the other shear stresses. Concentration changes ranged from −21–9nM, 19–53nM, 20–47nM, and 24 to 62nM for a step change to 1, 6, 10, and 20 dyn/cm^{2} respectively. B) To characterize the time course of NO concentration following a step change, concentration profiles were fitted with an exponential curve and time constants (t_{c}) were calculated. Exponential curves did not accurately reflect the time courses for a step change from 0.1 to 1 dyn/cm^{2}. (Mean and SE were plotted and statistics were calculated using the paired two-tailed t-test n= 8 for 1, 6 and 10 dyn/cm^{2} and n=6 for 20 dyn/cm^{2}, *p<0.05. For time constants, one value for 6 dyn/cm^{2} and for 10 dyn/cm^{2} were significant outliers and were excluded using Grubb’s test, α=0.05)

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