Vascular aging in the longest-living rodent, the naked mole rat

1 Department of Physiology, New York Medical College, Valhalla, New York; 2 Department of Biology, City College of New York, New York, New York; 3 The Barshop Institute for Longevity and Aging Studies and 4 Department of Physiology, University of Texas Health Science Center at San Antonio, Texas Submitted 23 November 2006 ; accepted in final form 27 March 2007 The naked mole rat (NMR; Heterocephalus glaber ) is the longest-living rodent known [maximum lifespan potential (MLSP): >28 yr] and is a unique model of successful aging showing attenuated declines in most physiological function. This study addresses age-related changes in endothelial function and production of reactive oxygen species in NMR arteries and vessels of shorter-living Fischer 344 rats (MLSP: 3 yr). Rats exhibit a significant age-dependent decline in acetylcholine-induced responses in carotid arteries over a 2-yr age range. In contrast, over a 10-yr age range nitric oxide (NO)-mediated relaxation responses to acetylcholine and to the NO donor S -nitrosopencillamine (SNAP) were unaltered in NMRs. Cellular superoxide anion (O 2 – ) and H 2 O 2 production significantly increased with age in rat arteries, whereas they did not change substantially with age in NMR vessels. Indicators of apoptotic cell death (DNA fragmentation rate, caspase 3/7 activity) were significantly enhanced ( 250–300%) in arteries of 2-yr-old rats. In contrast, vessels from 12-yr-old NMRs exhibited only a 50% increase in apoptotic cell death. In the hearts of NMRs (2 to 26 yr old), expression of endothelial NO synthase, antioxidant enzymes (Cu,Zn-SOD, Mn-SOD, catalase, and glutathione peroxidase), the NAD(P)H oxidase subunit gp91 phox , and mitochondrial proteins (COX-IV, ATP synthase, and porin, an indicator of mitochondrial mass) did not change significantly with age. Thus long-living NMRs can maintain a youthful vascular function and cellular oxidant-antioxidant phenotype relatively longer and are better protected against aging-induced oxidative stress than shorter-living rats. senescence; comparative biology; vascular disease; atherosclerosis; oxidative stress Address for reprint requests and other correspondence: Z. Ungvari, Dept. of Physiology, New York medical College, Valhalla, NY 10595 (e-mail: zoltan_ungvari{at}nymc.edu )