Transcriptional response to aging and caloric restriction in heart and adipose tissue.

Sustained caloric restriction (CR) extends lifespan in animal models but the mechanism and primary tissue target(s) have not been identified. Gene expression changes with aging and CR were examined in both heart and white adipose tissue (WAT) of Fischer 344 (F344) male rats using Affymetrix RAE 230 arrays and validated by quantitative reverse transcriptase-polymerase chain reaction (qRT-PCR) on 18 genes. As expected, age had a substantial effect on transcription on both tissues, although only 21% of cardiac age-associated genes were also altered in WAT.