Despite rising interest in the health problems of the elderly, information
on senescence-related alterations in essential metabolic pathways and their
responses to various chemicals is scarce. Although peroxisomal pathways ar
e involved in a multitude of cellular functions, little attention has been
given to the potential relationship between senescence of these organelles
and the process of aging and disease. Although the prevailing experimental
evidence points to a decline in liver peroxisomal enzyme activities and a m
uted response to peroxisome-proliferating chemicals in aged animals, it is
also evident that aged animals are more susceptible, in comparison to their
young counterparts, to the hepatocarcinogenic effects of these chemicals.
Furthermore, little is known about extraperoxisomal effects of peroxisome p
roliferators in aged animals. This review evaluates published studies on th
e impact of aging on basal hepatic peroxisomal metabolism, response to pero
xisome proliferators, and changes in signal transduction pathways involved
in these processes, with the aim of stimulating research efforts in this im
portant area. The potential intricate relationship among senescent peroxiso
mes, aged hepatocytes, and health are also discussed.