Histopathologic and electron microscopic investigation of the damage to liver tissue caused by parenteral nutrition combined with starvation in rabbits

Introduction
To conduct a histopathological examination of the damaging effects of the combination of parenteral nutrition (PN) with starvation on liver tissue using transmission electron and light microscopy.

Material and methods
Four groups (n = 14 each) consisting of equal numbers of female and male New Zealand rabbits were formed: a group left completely unfed and receiving full-dose PN (full-dose PN group), a group provided with feed covering half its nutritional needs and receiving half-dose PN (half-dose PN + oral nutrition group), a group provided with feed covering half its nutritional needs (semi-starvation group), and a group provided with feed covering all its nutritional needs (control group). After 10 days, all rabbits were weighed, anesthetized, and euthanized, and liver tissue samples were collected. Histopathologic examination was performed by a surgical pathologist blinded to the experimental groups. Portal inflammation, ballooning degeneration, apoptosis and fibrosis were evaluated and statistically analyzed.

Results
Severe portal inflammation, moderate portal fibrosis, slight ballooning degeneration, and moderate apoptosis were found in the full-dose PN group. Mild portal inflammation, fibrosis and mild apoptosis were found in the half-dose PN + oral nutrition group. The results of the other two groups were found normal.

Conclusions
Liver damage caused by PN combined with starvation can be devastating. The damage can be minimized by combining PN with enteral nutrition.