YANG, T.; BUFFENSTEIN, R.; O’CONNOR, T. P.; City College of New York; City College of New York; City College of New York: Disparate Age Effects On Gastrointestinal Enzymes In Naked Mole Rats

Aging is accompanied by declines in all physiological processes, including gastrointestinal (GI) function. Rats and mice for example, show age-related declines in both maltase and amino-oligopeptidase (AOP) activities and reduction in intestinal absorption. We assessed if naked mole-rats, which are the longest-lived rodents known, show similar declines in GI function with aging. Although naked mole-rats are mouse-sized rodents they have a maximum lifespan of more than 28 years in captivity, surpassing even much larger porcupines (>11 kg). We investigated age-related changes in maltase and AOP activity in 2, 5 and 10 year old naked mole-rats using colorimetric assays. We did not find significant differences in the activity of either enzyme along the length of the small intestine (proximal vs. distal), so we present mean values. AOP showed a typical decline with aging in that 2 year olds (n=6, 2.187±0.392 (mean ± SD) activity/gm intestinal tissue) were approximately 30% higher than the 10 years olds (n=5, 1.557±0.320; P<0.018). Reduced AOP activity correlates with attainment of adult mass and the concomitant decline in protein anabolism with increasing age. Mass-specific maltase activity was unchanged (P>0.05) with age (2 yrs: 8.579±3.616; 5 yrs: 17.982±11.004; 10 yrs: 8.242±7.376) and was lower in naked mole-rats than in mice. This difference might reflect lower metabolic rates and thus reduced energy requirements of naked mole-rats. Similarly both naked mole-rat basal metabolic rate and SGLT-1 glucose transporter activity did not change significantly with age. GI function of naked mole-rats is thus minimally affected as animals get older. Supported by a grant from AFAR to T. O’Connor.