EFFECT OF AGING AND DIET ON PROTON NMR-SPECTRA OF RAT URINE

500 MHz 1H NMR studies of rat urine are used to assess metabolic changes resulting from aging (0.5‐20 months) and changes in diet (casein versus chow). Aging rats fed chow diets decrease their excretion of citrate and 2‐oxoglutarate, while the output of taurine and creatinine increases. Only young rats (1 month or less postweaning) excrete significant amounts of betaine and trimethylamine‐N‐oxide. Rats fed casein diets for 1 month postweaning do not excrete 2‐oxoglutarate and excrete lower levels of hippurate, succinate, and citrate compared to rats fed chow diets. They also excrete N‐methylnicotinamide. These high resolution proton NMR studies provide metabolic profiles which are not readily available by other techniques. © 1991 Academic Press, Inc. Copyright © 1991 Wiley‐Liss, Inc., A Wiley Company