Delayed liver regeneration in peroxisome proliferator-activated receptor-alpha-null mice.

Peroxisome proliferator chemicals, acting via the peroxisome proliferator-activated receptor-alpha (Pparalpha), are potent hepatic mitogens and carcinogens in mice and rats. To test whether Pparalpha is required for hepatic growth in response to other stimuli, we studied liver regeneration and hepatic gene expression following partial hepatectomy (PH) of wild-type and Pparalpha-null mice. Pparalpha-null mice had a 12- to 24-hour delay in liver regeneration associated with a delayed onset and lower peak magnitude of hepatocellular DNA synthesis.