Joseph W. Kemnitz

 

 

Energy Metabolism and Aging in Nonhuman Primates

E-mail: kemnitz@primate.wisc.edu

Research Strength: Neurobiology of Disease

My laboratory studies mechanisms controlling energy balance and on the consequences of caloric excess or deficit on physiological systems. Current experiments focus on the biology of aging and metabolic problems associated with mid- and late-life. One topic concerns the pathogenesis of obesity and its complications, such as insulin resistance and diabetes mellitus. Pharmacologic interventions to promote maintenance of a healthy body weight and to ameliorate the complications of obesity also are being tested. Another research focus concerns dietary restriction and aging. We are testing the hypothesis that a moderate reduction in caloric intake will slow the rate of aging and ultimately extend lifespan in primates as has been shown for rodents and some other short-lived species. Results thus far indicate that the monkeys on the reduced diet have less body fat, increased sensitivity to insulin and lower insulin levels, improved lipid profiles, and other changes that are consistent with better health. We will extend these assessments in the near future to include cognitive function.

Selected Publications:

• Bruns, C.M., and J.W. Kemnitz. 2004. Sex hormones, insulin sensitivity, and diabetes mellitus. ILAR Journal 45: 160-169.
• Ramsey, J.J., J.W. Kemnitz., W. Newton, K. Hagopian, T.A. Patterson, and A.G. Swick. 2004. Food intake in rhesus monkeys following central administration of orexins. Regulatory Peptides. In press.
• Blanc, S., D. Schoeller, J. Kemnitz, R. Weindruch, R. Colman, W. Newton, K. Wink, S. Baum, and J. Ramsey. 2003. Energy Expenditure of rhesus monkeys subjected to 11 years of dietary restriction. J. Clinical Endocrinol. Metab. 88: 16-23.
• Gresl, T.A., R.J. Colman, T.C. Havighurst, D.B. Allison, D.A. Schoeller, J.W. Kemnitz. 2003. Dietary restriction and B-cell sensitivity to glucose in adult male rhesus monkeys. J. Gerontol. 58A: 598-610.
• Gresl, T.A., R.J. Colman, T.C. Havighurst, L.O. Byerley, D.B. Allison, D.A. Schoeller, J.W. Kemnitz. 2003. Insulin sensitivity and glucose effectiveness from three minimal models: Effects of energy restriction and body fat in adult male rhesus monkeys. Am. J. Physiol. 285: R1340-R1354.
• Zondervan, K., L. Cardon, R. Desrosiers, D. Hyde, J. Kemnitz, K. Mansfield, J. Roberts, J. Scheffler, D.E. Weeks, and S. Kennedy. 2002. The genetic epidemiology of spontaneous endometriosis in the rhesus monkey. Ann. N.Y. Acad. Sci. 955: 233-238.
• Eisner, J.R., D.A. Dumesic, J.W. Kemnitz, and D.H. Abbott. 2000. Timing of prenatal androgen excess determines differential impairment in insulin secretion and action in adult female rhesus monkeys. J. Clin. Endocrinol. Metab. 85: 1206-1210.
• Ramsey, J.J., R.J. Colman, N.C. Binkley, J.D. Christensen, T.A. Gresl, J.W. Kemnitz, and R. Weindruch. 2000. Dietary restriction and aging in rhesus monkeys: The University of Wisconsin study. Exp. Gerontol. 35: 1131-1149. [PDF]
• Colman, R.J., E.B. Roecker, J.J. Ramsey, and J.W. Kemnitz. 1998. The effect of dietary restriction on body composition in adult male and female rhesus macagues. Aging (Milano). 10: 83-92.
• Ramsey, J.J., J.W. Kemnitz, R.J. Colman, D. Cunningham, and A.G. Swick. 1998. Different central and peripheral responses to leptin in rhesus monkeys: brain transport may be limited. J. Clin. Endocrinol Metab. 83: 3230-3235.
• Ramsey, J.J., E.B. Roecker, R. Weindruch, and J.W. Kemnitz. 1997. Energy expenditure of adult male rhesus monkeys during the first 30 mo. of dietary restriction. Am. J. Physiol. 272: E901-E907