FIG. 5.

A diagram of the redox-window hypothesis. On the abscissa is the redox state from reductive state to oxidative state in a rightward direction. On the ordinate is collateral growth. Either reductive or oxidative stress will corrupt collateral growth and redox-dependent growth-factor signaling. The critical point of this figure is that the baseline redox state must be first determined, and only then can one accurately predict how an intervention will affect collateral growth. For example, in a control animal, apocynin inhibits collateral growth (because it shifts the redox state from a normal value to reductive stress), but in a JCR rat, apocynin stimulates collateral growth (because it shifts the redox state from oxidative stress to a normal value).