Journals of Gerontology Series A: Biological Sciences and Medical Sciences, Vol 51, Issue 5 B337-B345, Copyright © 1996 by The Gerontological Society of America
Oxidative status in senescence-accelerated mice
JW Park, CH Choi, MS Kim and MH Chung
Department of Pharmacology, Seoul National University College of Medicine, Chongno-gu, Korea.
The lipid peroxidation and activities of antioxidant enzymes were examined
in the livers of two substrains of senescence-accelerated mice (SAM):
senescence-resistant SAM-R/1 and senescence-prone SAM-P/1. Fluorescent age
pigment and conjugated diene levels in both substrains increased gradually
with age, but we found higher levels in SAM-P/1 at all ages tested.
Differences in the levels of lipid peroxidation products became more marked
with age. Among the enzymes studied, only mitochondrial superoxide
dismutase (SOD) in SAM-P/1 showed decreased activity in all age groups. The
specific mitochondrial SOD in that case was Cu,Zn-SOD. The amount of
Cu,Zn-SOD in mitochondrial fractions of SAM-P/1 was only half that of
SAM-R/1, whereas there were no apparent differences in the mRNA levels of
both SAM groups. Our study indicates that impaired transport of Cu,Zn-SOD
into mitochondria after cytosolic synthesis reduces defense against
oxidative stress. That reduction may be one of the factors contributing to
accelerated senescence in the SAM- P/1.
