Liver regeneration in dogs: morphologic and chemical changes

Abstract

Forty-four percent and 72% hepatectomy were carried out in dogs and the animals were sacrificed for biochemical and pathologic studies from 0.5 to 6 days later. Compensatory hypertrophy and hyperplasia (“regeneration”) were evident within 1 day, reached a maximum in 3 days, and were almost complete by 6 days. Coincident with the histologic events of regeneration were decreases in responsiveness of receptor adenyl cyclase to glucagon stimulation, increases of cyclic AMP, inconsistent changes in plasma insulin, and increases in plasma glucagon. These studies have standardized hepatic resection in dogs and they have focused attention upon some possible mechanisms that will require further study.

Fig. 1

Extent of hepatectomies. For 72% resection the two far right and two far left lobes were removed. For 44% resection only the two far left lobes were excised.

Fig. 2

Part of an enlarged hepatocyte from a dog subjected to 44% hepatectomy 24 hr earlier. Both rough and smooth endoplasmic reticulum are prominent. Fat globules (fg) are present. The number of lysosomes (ly) is increased. Glycogen is depleted. The mitochondria (m) appear normal. nu, Nucleus. Electron micrograph; × 20,250.