EFFECTS OF PARTIAL PANCREATECTOMY ON LIVER-REGENERATION IN RATS

Pancreatoduodenectomy with major hepatectomy has recently been employe d for patients with advanced biliary malignancies as potential curativ e surgery, However, postoperative liver decompensation is a major unfa vorable complication with this procedure; the main cause of the sequel ae is disturbance growth. In our present study, hepatic regeneration a nd nutritional status following simultaneous resection of the liver an d the pancreas were evaluated in an experimental animal model. Eighty SD rats were divided into four groups: control group (sham laparotomy, n = 20), 50% partial pancreatectomy group (Px, n = 20), 68% hepatecto my group (Hx, n = 20), and Px plus Hx group (n = 20). Five rats in eac h group were sacrificed for blood and liver collection on the first, s econd, third, and seventh postoperative days, respectively. One hour b efore sacrifice, 5-bromo-2-deoxyuridine (20 mg/kg/body weight) was inj ected intraperitoneally and BrdU-labeled nuclei in the liver were demo nstrated immunohistochemically to allow examination of the mitotic res ponse. Body weight increase rate (BWR), the liver wet weight (LWW), th e ratio of the LWW to body weight, and the liver regeneration rate wer e calculated. Serum activity of alanine aminotransferase and levels of serum bilirubin and albumen were also measured. The LWW was relativel y decreased after simple Px with no change in the BrdU labeling index or mitotic index. The highest peak of DNA synthesis of hepatocytes in the remaining lobes was markedly reduced on the first day after Hx + P x, with a delay in the hepatic regeneration response extending to the seventh postoperative day. Decrease in BWR in both the Px group and th e Hx + Px group was observed on the first 3 postoperative days, with g ain of BWR in the former case being slower. Removal of a portion of th e pancreas can decrease hepatic weight under both normal and regenerat ive conditions. Simultaneous major resection of the liver and a portio n of pancreas results in reduction and delay in the highest peak of DN A synthesis of hepatocytes in the remnant liver, We speculate that the pancreatic exocrine glands may play a distinct role in supporting the liver and in triggering hepatocyte proliferation. (C) 1997 Academic P ress.