Alterations of remnant liver carnitine and serum carnitine concentrations after partial hepatectomy in rats.

The role of carnitine in the early phase of liver regeneration after partial hepatectomy has been a controversial issue. The purpose for this study was to evaluate the alterations of remnant liver carnitine and serum carnitine concentrations in partial-hepatectomized rats. Partial hepatectomy, with resection of the median and left lateral lobes (67%), was done in 40 male Wistar rats weighing about 200 g. Another group of 40 rats underwent a sham-operation for comparison. All the rats underwent fasting for 4 hours before surgical procedure and 2 hours after surgery. They were killed at 6, 24, 48 or 72h after the operation, ten rats for each time. The serum carnitine concentration, remnant liver carnitine content, serum free fatty acid (FFA), acetoacetate (AA) and beta-hydroxybutyrate (BB) concentrations were measured. It was found that: (1) the serum carnitine concentration increased in the early posthepatectomized stage; (2) the carnitine content in the remnant liver increased in the early posthepatectomized stage; and (3) the serum FFA and its metabolites markedly increased with a depressed ketone body ratio noted in the early post-hepatectomized stage. These results supported the theory that regenerating liver utilized free fatty acids as an immediate main substrate. The utilization then decreased. Because of a marked increase of the carnitine concentration in the remnant liver and serum, it is suggested that the carnitine contents were sufficient for liver regeneration. There must be other reasons for the decreased utilization of free fatty acids.