title: Aging effect on myeloperoxidase in rat kidney and its modulation by calorie restriction.
abstract: Myeloperoxidase (MPO), a heme protein existing in neutrophil and monocyte, is implicated in various stages of inflammatory conditions with the production of a variety of potent oxidants. To investigate the extent of the involvement of MPO in aging, we measured MPO activities in kidney of rats at different ages maintained with an ad libitum (AL) or a calorie restriction (CR) dietary regimen. Results showed that the MPO activities increased during aging in AL rats, but were significantly attenuated by CR. This result was consistent with altered protein level of MPO during aging. In addition, we were able to detect dityrosine that is a stable end MPO-oxidation product. The amount of dityrosine increased in old AL, but not in old CR rats. To examine the source responsible for increased MPO activity during aging for leukocyte recruitment and infiltration, the levels of vascular cell adhesion molecule (VCAM-1) protein were measured. The level of VCAM-1 showed age-dependent increase in AL rats, which was correlated with higher activity of MPO in old AL rats. Furthermore, we have found that LPS-induced inflammation increased the activity and protein levels of MPO, and VCAM-1 expression in young rat kidneys. These findings suggest that increased MPO activity with aging may related to increased recruitment of inflammatory cells, contributing to protein oxidation accumulation in the aging process. We propose that age-related alterations of MPO, dityrosine, and VCAM were modulated by CR through its anti-inflammatory action.
authors.affiliation: Department of Pharmacy, College of Pharmacy, Aging Tissue Bank, Longevity Life Science and Technology Institutes, Pusan National University, Gumjung-gu, Busan 609-735, South Korea.
authors.forename: Tae Gen
authors.initials: TG
authors.lastname: Son
authors.forename: Yani
authors.initials: Y
authors.lastname: Zou
authors.forename: Byung Pal
authors.initials: BP
authors.lastname: Yu
authors.forename: Jaewon
authors.initials: J
authors.lastname: Lee
authors.forename: Hae Young
authors.initials: HY
authors.lastname: Chung
mesh_terms: D000375:Aging / Q000187:drug effects / Q000502:physiology*; D000818:Animals; D031204:Caloric Restriction; D004032:Diet; D002149:Energy Intake; D007249:Inflammation / Q000201:enzymology / Q000209:etiology; D007668:Kidney / Q000187:drug effects / Q000201:enzymology*; D008070:Lipopolysaccharides / Q000494:pharmacology; D008297:Male; D010084:Oxidation-Reduction; D018384:Oxidative Stress; D009195:Peroxidase / Q000378:metabolism*; D051381:Rats; D011916:Rats, Inbred F344; D014443:Tyrosine / Q000031:analogs & derivatives* / Q000378:metabolism; D019010:Vascular Cell Adhesion Molecule-1 / Q000378:metabolism
chemical_list: D008070:Lipopolysaccharides; D019010:Vascular Cell Adhesion Molecule-1; D014443:Tyrosine; C007543:dityrosine; D009195:Peroxidase