Intricacies of redoxome function demonstrated with a simple in vitro chemiluminescence method, with special reference to vitamin B12 as antioxidant.
Bottom Line: The homeostatic control of the redox system (the redoxome) in mammalian cells depends upon a large number of interacting molecules, which tend to buffer the electronegativity of cells against oxidants or reductants.Simple dose-responses were found, as for the PMN proteins S100A9 (A9) and S100A8 (A8), and the system also revealed the reducing capacity of vitamin B12 (Cbl) and lutein.Biphasic responses were also recorded for some dose-response set-ups and are tentatively explained by a 'balance hypothesis' for the redoxome.
Affiliation: Department of Physiology, Institute of Basic Medical Sciences, University of Oslo, Oslo, Norway.Show MeSH
Mentions: The chemiluminescence induced by MPO was inhibited by recombinant A9 and brain-derived S100B (Fig. 5). NaOCl itself strongly decreased the MPO activity, and 10 μm NaOCl was sufficient to cause 85% inhibition of chemiluminescence (Fig. 6, insert). This inhibition was counteracted in a dose-dependent manner by A9 (Fig. 6), which itself (4 μg/ml) exerted approximately 40% inhibition of the MPO activity (Fig. 6). It is noteworthy that two regulators, NaOCl and A9, which when added alone had an inhibitory effect on MPO-generated chemiluminescence, stimulated light emission when combined (Fig. 6) (P < 0.05). Altogether, we have found considerable variability in the A9 effect on MPO chemiluminescence, and mostly so that strong inhibition correlated positively with low chemiluminescence values in the MPO control.
Affiliation: Department of Physiology, Institute of Basic Medical Sciences, University of Oslo, Oslo, Norway.