Muscular Apoptosis but Not Oxidative Stress Increases with Old Age in a Long-Lived Diver, the Weddell Seal

Authors

Kaitlin N. Allen, University of California, BerkeleyFollow
Jose Pablo Vazquez-Medina, University of California, Berkeley
John M. Lawler, Texas A&M University
Jo-Ann E. Mellish, University of Alaska, Fairbanks
Markus Horning, Oregon State University
Allyson G. Hindle, University of Nevada, Las VegasFollow

Document Type

Article

Publication Date

6-6-2019

Publication Title

Journal of Experimental Biology

Publisher

Company of Biologists

Volume

222

Issue

12

First page number:

1

Last page number:

9

Abstract

Seals experience repeated bouts of ischemia–reperfusion while diving, potentially exposing their tissues to increased oxidant generation and thus oxidative damage and accelerated aging. We contrasted markers of oxidative damage with antioxidant profiles across age and sex for propulsive (longissismus dorsi) and maneuvering (pectoralis) muscles of Weddell seals to determine whether previously observed morphological senescence is associated with oxidative stress. In longissismus dorsi, old (age 17–26 years) seals exhibited a nearly 2-fold increase in apoptosis over young (age 9–16 years) seals. There was no evidence of age-associated changes in lipid peroxidation or enzymatic antioxidant profiles. In pectoralis, 4-hydroxynonenal-Lys (4-HNE-Lys) levels increased 1.5-fold in old versus young seals, but lipid hydroperoxide levels and apoptotic index did not vary with age. Glutathione peroxidase activity was 1.5-fold higher in pectoralis of old versus young animals, but no other antioxidants changed with age in this muscle. With respect to sex, no differences in lipid hydroperoxides or apoptosis were observed in either muscle. Males had higher HSP70 expression (1.4-fold) and glutathione peroxidase activity (1.3-fold) than females in longissismus dorsi, although glutathione reductase activity was 1.4-fold higher in females. No antioxidants varied with sex in pectoralis. These results show that apoptosis is not associated with oxidative stress in aged Weddell seal muscles. Additionally, the data suggest that adult seals utilize sex-specific antioxidant strategies in longissismus dorsi but not pectoralis to protect skeletal muscles from oxidative damage.

Keywords

Pinniped, Aging; Senescence; Antioxidants; Redox; Ischemia-reperfusion

Disciplines

Animal Sciences | Terrestrial and Aquatic Ecology | Zoology

File Format

pdf

File Size

1.275 KB

Language

English

Repository Citation

Allen, K. N., Vazquez-Medina, J. P., Lawler, J. M., Mellish, J. E., Horning, M., Hindle, A. G. (2019). Muscular Apoptosis but Not Oxidative Stress Increases with Old Age in a Long-Lived Diver, the Weddell Seal. Journal of Experimental Biology, 222(12), 1-9. Company of Biologists.
http://dx.doi.org/10.1242/jeb.200246