Is the biological antioxidant system integrated and regulated?

It is proposed that there is biological regulation of the low molecular wei ght antioxidant (LMWA) status of the body, and that these different antioxi dants work in concert and in homeostasis as a system analogous to the regul ation of acid-base status (pH). The theoretical design characteristics for such a system include regulation, inducibility, interactivity and balance w ith the beneficial properties of reactive oxygen species. Testing the hypot hesis requires developing suitable methodologies (such as measurement of th e redox state) for assessing the total ratio of antioxidant to oxidant acti vity of both tissues and biological fluids, since it is not clear whether p lasma antioxidant status reflects that of the tissues as well. This concept , if accepted, may help explain the contradictions relating to antioxidant therapy and lead to more rational recommendations for dietary intake. it ma y also help explain the effects of manipulating (increasing/decreasing) spe cific antioxidants on the overall antioxidant status in health and disease. (C) 1999 Harcourt Publishers Ltd.