Regeneration of liver in rats in the absence of portal splanchnic organs and a portal blood supply.

Rats were eviscerated of portal splanchnic organs; the stomach, intestines, pancreas, and spleen were excised and the portal vein was ligated and sectioned, leaving the hepatic artery as the sole purveyor of blood to the liver. The animals were maintained for 24 or 48 hr by continuous i.v. infusion. Partial hepatectomy at the time of evisceration induced substantial increases in DNA synthesis and mitosis, al though these responses were somewhat delayed and less pronounced than in noneviscerated, hepatectomized con trols. Thus it now seems open to question whether so-called portal blood hepatotrophic factors are the primary regula tors of hepatic regeneration, although insulin has not been entirely excluded. In rats, as previously demonstrated in dogs, evisceration does not prevent hepatic regeneration. In rats, at least, the hepatic artery alone is capable of supporting active liver cell proliferation.