The relationship of iron and glycogen to the in vitro, ultraweak chemiluminescent analysis of lipid peroxidation in rabbit hearts of varying ages.
Oxidative stress, which occurs when prooxidants overwhelm antioxidants, has been implicated as a cause of tissue damage related to ischemia and reperfusion. Neonatal animal and human hearts have been shown to differ in their response to oxidative stress, but the mechanism for this difference is unclear. To study this phenomena, crude homogenates of hearts from 4-day, 4-week, and adult (> 6 months) New Zealand rabbits were studied by chemiluminescence after exposure to O2/CO2 (95/5) or tert-butyl hydroperoxide (TBHP). Loosely bound iron and glycogen concentrations were also determined. The 4-day hearts exhibited more chemiluminescence after both oxygen and TBHP-driven stress. When exposed to O2, they reached a maximum rate of chemiluminescence in one-third less time and exhibited a 22% higher count rate. Likewise, when stimulated by TBHP, their rate was 44% higher than the hearts of both older groups. The 4-day hearts also had a 40% greater content of loosely bound iron that may, in part, explain their greater susceptibility to oxidative stress. Although the youngest hearts had the highest glycogen content, that did not offer protection against oxidative stress, as has been previously reported for liver.
Jenkins
R R
RR
Biology Department, Ithaca College, NY 14850.
Kohman
L J
LJ
Veit
L J
LJ
D000375:Aging; D000818:Animals; D006003:Glycogen / Q000378:metabolism*; D007501:Iron / Q000378:metabolism*; D015227:Lipid Peroxidation; D008163:Luminescent Measurements; D009206:Myocardium / Q000378:metabolism*; D010100:Oxygen / Q000494:pharmacology; D010545:Peroxides / Q000494:pharmacology; D011817:Rabbits; D020122:tert-Butylhydroperoxide
D010545:Peroxides; D006003:Glycogen; D020122:tert-Butylhydroperoxide; D007501:Iron; D010100:Oxygen