| Research Abstract |
After partial hepatectomy in the rat, the remnant liver rapidly regenerates within a week. To evaluate the involvement of angiogenic growth factor in regeneration of hepatic endothelial cells, I determined the expression of vascular endothelial cell growth factor (VEGF-A and VEGF-B) and basic fibroblast growth factor (beGf) in the regenerating liver and other organs since low molecular weight VEGF (VEGF 121) could enter the blood and might be involved in vascular endothelial cells in the regenerating liver, In the liver, VEGF-A expression was increased immediately after partial hepatectomy, and sustained high level of the expression. The expression of bFGF was tend to increase, but the expression of VEGF-B was not changed. No change was observed in splicing variants of VEGF-A and VEGF-B in the regenerating liver. Lung and heart persistently expressed VEGF-A at high levels, and the former, but not the latter, expressed VEGF 121. During the regeneration of liver, no apparent change was s
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een in the expression of VEGF-A in the both organs. The VEGF-A expression in spleen and kidney was almost doubled, and VEGFl2 I was detected in spleen. The expression of VEGF-B was increased in lung, heart, spleen and small intestine, although it was not changed in liver and kidney. These results suggest that hepatic expression of VEGF-A and bFGF in the regenerating liver might contribute the regeneration of non-parenchymal cells, and that VEGFl2I produced in lung and spleen and VEGF-B from lung, heart, spleen and small intestine might also be involved in the regeneration. The mechanism by which expression of these factors increases is still obscure. However, we found the expression of VEGF-A and bFGF in brawn adipose tissue was controlled by the sympathetic nerve. It should be also noted that the sympathetic nerve systems are activated during the liver regeneration. Therefore, the expression of VEGF-A, VEGF-B and bFGF might be regulated by the sympathetic nerve systems like brawn adipose tissue. Less
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