There has been increasing number of patients who are subjected to major hepatic resection, and with this trend, mode of regeneration following such resection has become a major point of interest to all of us. Study along this line is even more desirable in Korea when one takes into account of the fact that the incidence of primary carcinoma of the liver is rather high among our population.
Nutritional status of these patients, before and following surgery, however, is variable depending upon circumstances and such variation has been believed to be partially responsible for varying pattern of regeneration following resection.
Triggered by initial experiment of Brues(1936), many studies about the effect of nutritional conditions upon regeneration in experimental animals has been carried out, but there have been, many differences of opinion in interpreting their results. Some of the reasons for such disagreement appear to be due to differences in experimental methods employed.
Author carried out 2 experiments using 97 male albino rats. In first experiment, rats were subjected to starvation of various degree for 72 hours prior to 67.4% hepatic resection, and the effect of such pre-operative starvation upon regeneration was studied by examining DNA content and 3H-thymidine incorporation in liver tissue 24 hours after hepatectomy. In second experiment, rats were subjected to starvation of various degree for 72.hours following 67.4% hepatectomy, and the effect of such conditions upon liver regeneration was studied by exami-ning wet weight of liver at 72nd post-operative hour.
Each of the 2 experiments were further subdivided into 5 groups in which various degree of nutritional supply was maintained by intravenous feeding in some groups in order to be
certain of the amount given to each individual animals.
The following results were obtained;
Experiment I.
1. The highest 3H-thymidine incorporation into DNA of liver tissue was noted in Group 1 (normal diet), 8,424.5±3,201. 1cpm/mg DNA, and it was statistically significant compared to other groups(p<0.01).
2. There were no significant differences in mean, values of 3H-thymidine incorporation between starved and semi-starved groups. Group 2 (total starvation): 5,128.3-±120.9, Group 3 (glucose IV): 3,658.1±2,392.4, Group 4 (amino acids IV): 3,495.1±1, 481.4, Group 5 (glucose & amino acids IV): 4, 286.6±1,992.4cpm/mg DNA.
3. The lowest DNA content per gram of wet liver tissue was noted in Group 1, 2.026-±-0.647mg, but it could not be used as an index of regeneration in comparison with other groups.
4. Excluding Group 1, Group 5 showed the highest DNA content, 2.699±0.687mg/gm of wet liver. Group 2, 3 and 4 showed slightly decreased mean values, 2.326±0.416, 2.263± 0. 396 and 2.536+0.671mg/gm of wet liver, respectively.
Experiment II.
1. In Group 1 (normal diet), the regeneration rate by liver weight was 69.31±8.51% which was the highest rate and the difference was significant when compared to other groups. (p< 0.01)
2. The lowest regeneration rate was noted in Group 2, 37.12±9.11%.
3. The other groups showed insignificant differences in regeneration rate but in Group 5 (51.36±5.09%), it was a little higher than in Group 3 (46.38±4.46%) or Group 4 (47.99± 7.14%).
With these results it can be concluded cautiously that starvation has a profound effect upon liver regeneration and small amounts of intravenous injection of nutrients in starvation has only minor effects. Therefore, it can be concluded, on the basis of present study that any degree of pre-operative and post-operative malnutrition exerts deleterious effect upon liver regeneration and that parenteral supplement in such status must include amino acids as well as glucose in large amounts. Most of all, return to normal oral food intake at the earliest possible stage appears to be most important if one is to expect: prompt liver regeneration.
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