GLYCOLYSIS AND GLUCOREGULATION AS TARGETS FOR CALORIE RESTRICTION MIMETICS





G.S. Roth, M.A. Lane, J.A. Mattison, D.K.Ingram

NIA, Baltimore, MD 21224



Dietary caloric restriction (CR) has proven to exert beneficial "anti-aging" and "anti-disease" effects in animal models ranging from invertebrates to primates. Since three of the most robust physiological hallmarks of CR (decreased plasma levels of insulin, lower body temperature, and maintenance of plasma dehydroepiandrosterone sulfate concentrations) also correlate with survival in men, this intervention could benefit humans as well, at least in theory. Unfortunately, most individuals would be unwilling, or unable, to reduce their caloric intake by 30% over the bulk of their adult lifespan, even to achieve such positive effects.

For this reason, we have undertaken a search for CR mimetics, agents that can exert the same biological effects as CR, but without reducing food consumption. One promising class of candidate compounds are those which affect glycolysis and/or glucoregulation. Initial studies with 2-deoxyglucose (2DG) have demonstrated the feasibility of this approach. Rats fed 2DG exhibit lower body temperature and plasma insulin (as well as lower plasma glucose under some conditions), and a trend toward greater survival during the mid-portion of the lifespan, while maintaining essentially ad libitum food intake. Unfortunately, 2DG has a very narrow window between efficacy and toxicity, which is reduced further by exposure time, and will probably render this compound impractical for human application. However, two "anti-diabetic" agents, phenformin and metformin, appear to mimic some of the bioeffects of 2DG without apparent toxicity. Preliminary experiments suggest that the latter can increase median and maximal survival of rats to the same extent as 30% CR.

Clearly, additional studies will be necessary to refine our approach and determine an optimal intervention protocol. However, taken together, the above results support the possibility of identifying agents that regulate glucose metabolism, without reducing caloric intake, as possible CR mimetics for eventual human use.




Key words: CR mimetics, aging







Problems or questions regarding this site should be directed to webmaster@americanaging.org