Please forgive, but I lifted this abbreviated antioxidant enzyme
defense system (in ASCII form) scheme from Dr. Mark Kukucka's PhD
dissertation because I couldn't find anything else like it online!
Mechanisms by which hypoxia augments Leydig cell viability and
differentiated cell function in vitro
by Mark A. Kukucka, MS, DVM, PhD
Department of Biomedical Sciences
Virginia-Maryland Regional College of Veterinary Medicine
Virginia Polytechnic Institute & State University
Blacksburg, Virginia 24061-0442
found at:
http://scholar.lib.vt.edu/theses/available/etd-06062008-170416/
H2O
/\
|
| Catalase
|
oxidases SOD | Fe+2
O2 --------> O2*- --------> H2O2 ----\----> OH* --------> H2O
| Fe+3
|
| 2GSH
| / /\
| Glutathione Glutathione
| peroxidase reductase
| \/ /
| GSSG
\/
H2O
Figure 1. The Antioxidant Enzyme Defense System Scheme
Other publications by Dr. Mark A. Kukucka
http://www.nextbio.com/b/literature/literature.nb?author=MA+Kukucka 
