On the Effect Of Autonomic Nervous System and Portal Blood Supply to Liver Regeneration

Abstract

A. On the Effect of Autonomic Nervous System to Liver Regeneration
2/3 partial hepatectomy in rat was performed by the method of Higgins & Anderson. At the same time, bilateral N. vagus and N. splanchnicus major were transected just under the diaphragma.
As the indicator of the liver regeneration, the regeneration ratio of Canzanelli and P³² incorporation to DNA were studied in the course of the time.
Experimental results were as follows.
(1) Decrease of regeneration ratio, when N. vagus was transected, was statistically significant, at the 7th day after partial hepatectomy. Transection of N. splanchnicus major was no effect upon the regeneration ratio.
(2) Transection of N. vagus and of N. splanchnicus major, both had no effects upon P³² incorporation to DNA after partial hepatectomy.
Therefore, the transaction of N. vagus is supposed to influence, not to the cell division itself but to the hypertrophy of individual cell after cell division.
B. On the Effect of Portal Blood Supply to Liver Regeneration
2/3 partial hepatectomy was performed by the method of Higgins & Anderson. 1/3 partial hepatectomy was performed by the resection of left lateral lobe. At the same time, bilateral N. vagus and N. splanchnicus major were transected just under the diaphragma. Deprivation of portal blood supply was performed by the ligation of the branch of portal vein to right lateral lobe.
As indicators of liver regeneration after partial hepatectomy, weight changes of each lobes, regeneration ratio of Canzanelli, mitosis index, P³² incorporation to DNA, H³-thymidine autoradiography were studied.
Experimental results were as follows.
(1) When the ligation of the branch of the portal vein was performed, the ligated lobe markedly decreased its weight and cell division was not found in this lobe. On the other hand, in the unligated lobes, the cell division was found same degree as 1/3 partial hepatectomy.
(2) When 1/3 partial hepatectomy was performed at the same time as the ligation of the branch of the portal vein, the ligated lobe markedly decreased its weight and cell division was not found in this lobe. In the unligated lobe, the cell division was found same degree as 2/3 partial hepatectomy.
(3) When 2/3 partial hepatectomy was performed at the same time as the ligation of the branch of the portal vein, the ligated lobe maintained its initial weight and showed the cell division same degree as 2/3 partial hepatectomy. And the course of this cell division had the tendency to delay. On the other hand, in the unligated lobe, more marked cell division than 2/3 partial hepatectomy only, occured.
(4) The cell division when 2/3 partial hepatectomy was performed, was more marked than the cell division when 1/3 partial hepatectomy was performed.
As the result of this study on the effect of the deprivation of portal blood supply to liver regeneration after partial hepatectomy, the existence of the humoral factor was supposed which stimulate the cell division. This humoral factor was thought to act from the unligated lobe to ligated lobe and at the same time, to act from the ligated lobe to unligated lobe.