Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “LIVER REGENERATION”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 379 records · Page 21Linked to original sources

The effect of fenestration procedure on liver regeneration in a case of polycystic liver disease.

We encountered a case of polycystic liver disease for which unroofing and fenestration procedures were performed. The patient was a 55-year-old Japanese female with epigastralgia and abdominal fullness. On computed tomography, millions of low-density areas were seen, particularly in S6, 7, where huge cysts 15 cm in diameter were observed. Magnetic resonance imaging showed a T1 low T2 high-intensity lesion, which was compatible with simple cysts. Unroofing for the cysts in S6, 7 and fenestration of other cysts were performed. Histological examination revealed cuboidal and flat monolayer epithelia with no dysplasia in the wall of the cysts. The postoperative course was uneventful, and the patient's abdominal symptoms remarkably improved. The percentage of the liver volume which was increased in relation to standard liver volume was reduced from 241% (3386 mL: liver parenchyma 750 mL, cysts 2636 mL) to 180% (2525 mL, 1566 mL, 959 mL, respectively) after surgery. The potent mitogen, hepatocyte growth factor, was rapidly increased after the operation and stayed high during the observation period. In this patient, since no liver resection was performed, liver regenerative stimulus was considered to be the loss of space. This phenomenon represents a model of liver regeneration in response to loss of occupied space in an absence of shear stress.

Cysts↗

Portal vein ligation and partial hepatectomy differentially influence growth of intrahepatic metastasis and liver regeneration in mice.

BACKGROUND/AIMS: Since modern treatment of liver metastases includes serial hepatectomies and portal vein obstruction, we investigated the effects of portal vein ligation (PVL) and partial hepatectomy (PH) on tumor growth. METHODS: The effects of 70% PH and PVL on liver and lung metastases were evaluated in mice. Tumor growth and liver regeneration were assessed by morphometry and immunohistochemistry for PCNA and BrdU. The effect of growth factors of liver regeneration on CT-26 cells was tested in vitro, and TGF-beta secretion of CT-26 cells was measured by ELISA. RNA synthesis of TGF-beta and activin A was measured by RT-PCR. RESULTS: Liver regeneration after PH and PVL was similar in tumor-free mice. Intrahepatic tumor growth was lower after PH than after PVL (p=0.016). Extrahepatic tumor growth was not different. In contrast to PVL, liver regeneration was delayed after PH in metastatic livers (p=0.001). Tested growth factors of liver regeneration stimulated CT-26 cells in vitro, and CT-26 secreted significant amounts of TGF-beta in vitro and in vivo. CONCLUSIONS: Although similar in tumor-free mice, liver regeneration significantly differed between PVL and PH in metastatic livers. In addition, PH and PVL differently affected intrahepatic tumor growth.

Animals↗

Severe steatosis increases hepatocellular injury and impairs liver regeneration in a rat model of partial hepatectomy.

OBJECTIVE: The aim of this study was to assess the influence of severe steatosis with inflammation on hepatocellular recovery after 70% hepatectomy in a rat model of diet-induced steatosis. BACKGROUND: Patients with steatosis have an increased risk of inflammatory complications after liver resection. This might be attributable to Kupffer cell-mediated inflammation in steatotic livers causing progressive injury. METHODS: Male Wistar rats were fed a standard methionine- and choline-deficient diet for 1 or 5 weeks. A 70% partial hepatectomy (PH) was performed, after which rats were killed at 24, 48, or 72 hours. The extent of steatosis and inflammation was determined by assessment of hepatic triglycerides, cytokine content, and histopathology. Outcome parameters were: liver regeneration (MIB-5 proliferation rate, mitotic index, and regenerating liver mass), hepatocellular injury (plasma aminotransferases, lipid peroxidation, histopathology, and apoptosis), Kupffer cell-mediated proinflammatory response (TNF-alpha, IL-1beta, IL-6, IL-10 in plasma and liver) and antioxidant content (total glutathione). RESULTS: Methionine- and choline-deficient diet induced uncomplicated steatosis after 1 week (<30% hepatocytes affected without inflammation) and severe steatosis after 5 weeks (>60% hepatocytes affected, including prominent inflammation) as confirmed by histopathology. After PH, liver regeneration was impaired at all time points in the severe steatosis group as compared with the mild and control groups (P < 0.05). Hepatocellular injury was significantly increased in the severe steatosis group at all time points (P < 0.05). Kupffer cell-mediated inflammatory responses were aggravated in the severe steatosis group along with decreased antioxidant content (P < 0.05). Necrosis was the main type of cell death in severe steatotic livers compared with mainly apoptotic cell death in mild steatotic and normal livers. CONCLUSION: Steatosis with prominent inflammation impaired liver regeneration probably because of increased hepatocellular lipid peroxidation and damage in concert with Kupffer cell-mediated proinflammatory responses. These results suggest an increased risk of performing extensive liver resection in the presence of severe steatosis.

Animals↗

Rapid induction in regenerating liver of RL/IF-1 (an I kappa B that inhibits NF-kappa B, RelB-p50, and c-Rel-p50) and PHF, a novel kappa B site-binding complex.

The liver is one of the few adult tissues that has the capacity to regenerate following hepatectomy or toxic damage. In examining the early growth response during hepatic regeneration, we found that a highly induced immediate-early gene in regenerating liver encodes RL/IF-1 (regenerating liver inhibitory factor) and is the rat homolog of human MAD-3 and probably of chicken pp40. RL/IF-1 has I kappa B activity of broad specificity in that it inhibits the binding of p50-p65 NF-kappa B, c-Rel-p50, and RelB-p50, but not p50 homodimeric NF-kappa B, to kappa B sites. Like RL/IF-1, several members of the NF-kappa B and rel family of transcription factors are immediate-early genes in regenerating liver and mitogen-treated cells. We examined changes in kappa B site binding activity during liver regeneration and discovered a rapidly induced novel kappa B site-binding complex designated PHF [posthepatectomy factor(s)]. PHF is induced over 1,000-fold within minutes posthepatectomy in a protein synthesis-independent manner, with peak activity at 30 min, and is not induced by sham operation. PHF is distinct from p50-p65 NF-kappa B, which is present only in the inactive form in liver posthepatectomy. Although early PHF complexes do not interact strongly with anti-p50 antibodies, PHF complexes present later (3 to 5 h) posthepatectomy react strongly, suggesting that they contain a p50 NF-kappa B subunit. Unlike p50-p65 NF-kappa B, c-Rel-p50, and RelB-p50 complexes, PHF binding to kappa B sites is not inhibited by RL/IF-1. One role of RL/IF-1 in liver regeneration may be to inhibit p50-p65 NF-kappa B activity present in hepatic cells, allowing for the preferential binding of PHF to kappa B sites. Because PHF is induced immediately posthepatectomy in the absence of de novo protein synthesis, PHF could have a role in the regulation of liver-specific immediate-early genes in regenerating liver.

Animals↗

The influence of spleen size on liver regeneration after major hepatectomy in normal and early cirrhotic liver.

BACKGROUND/PURPOSE: The relationship between liver regeneration and spleen size after major hepatectomy in normal and cirrhotic liver was studied by single photon emission computed tomography (SPECT). MATERIALS AND METHODS: Twenty-six patients, 18 patients with normal liver and eight patients with cirrhotic liver, receiving major hepatectomy were included. Liver and spleen volumes were measured by SPECT before major hepatectomy, 6 months, 1 year and 2 years after operation. The correlation of liver and spleen volume during liver regeneration was analyzed. RESULTS: In both groups, the residual liver volume increased within the first year and decreased in the second year. No difference in regeneration ability was found. The spleen volume in cirrhotic liver was increased, with a trend similar to normal liver during the first year. In contrast, the increased spleen volume persisted up to the second year in cirrhotic patients. Age per year, the female sex, and body surface index had a positive correlation with increased percentage of liver volume. The spleen volume per 100 ml with time played a significantly negative role in increasing percentage of liver volume, confidence interval: -2.16 to -27.92, P=0.011. CONCLUSION: In early cirrhotic liver within normal functional limits, the liver still could regenerate as a normal liver after major hepatectomy in 1 year. Age, the female sex, and body surface index had positive correlation but the size of spleen volume played a negative role to regenerative liver volume.

Adult↗

Remnant liver regeneration and spleen volume changes after living liver donation: influence of the middle hepatic vein.

BACKGROUND AND OBJECTIVES: Graft harvest with or without the middle hepatic vein (MHV) affects venous return and function of the remaining liver. The aims of this study are to compare the remnant liver volume and spleen changes in the donors of different types of graft harvest and to evaluate the influence of resection with or without the MHV on the remnant liver volume regeneration, spleen volume change and serum total bilirubin. PATIENTS AND METHODS: A total of 165 donors were grouped according to the type of graft harvest: 88 donors underwent left lateral segmentectomy (LLS), 10 donors underwent extend LLS or left lobectomy (LL), and 67 donors underwent right lobectomy (RL). Groups LLS and LL were later combined as group LH (left hepatectomy, n = 98). There were 68 men and 97 women. The mean age was 32.9 +/- 8.1 yr. The total liver volume (LV) and spleen volume (S1) before graft harvest, graft weight (GW), regenerated liver volume (LV(6m)) and spleen volume (S2) six months post-donation were calculated. RESULTS: There were no significant differences in the regenerated liver volume six months postoperation (LV(6m)) and recovery ratio (LV(6m)/LV x 100%) among the different groups, albeit significant smaller LV(6m) in both groups compared with the initial liver volume was noted. Postoperative spleen volume (S2), average spleen ratio (S2/S1) and spleen change ratio were significantly larger and higher in group RL than in group LH. A significant increase in spleen volume was noted in both groups six months after graft harvest. A significantly higher TB in group RL (4.1 +/- 1.7 mg/dL, range: 1.4-8.5 mg/dL) was noted compared with that of group LH (1.6 +/- 1.0 mg/dL, range: 0.7-6.2 mg/dL). CONCLUSION: There was a significant increase in the regenerated remnant liver and splenic volumes six months postoperation in all types of hepatectomy following living donor hepatectomy, and there was no difference in the mean TB levels among donors whether the MHV was included or not in the graft.

Adult↗

Portal blood flow and liver regeneration in auxiliary partial orthotopic liver transplantation in a canine model.

Functional competition has been shown to lead to a detrimental outcome in auxiliary liver transplantation. We evaluated the interaction in auxiliary partial orthotopic liver transplantation between the native liver and the graft in terms of portal flow and regeneration. The need for diversion of the portal flow to the graft was also assessed. Reduced-size liver grafts were transplanted orthotopically after partial hepatectomy in beagles. There were two groups: the preserved group, where portal inflow to the native liver was preserved, and the ligated group, where it was interrupted. Portal flow was measured serially and liver regeneration was evaluated on postoperative day 5. Functional competition was not observed in the preserved group. On the other hand, ligation of the native liver portal vein had no obviously detrimental effects on the remnant native liver. This leads to the conclusion that the portal vein to the native liver can be safely ligated to prevent functional competition.

Animals↗

Sucrose administration to partially hepatectomized rats: a possible model to study ethanol-induced inhibition of liver regeneration.

Although acute ethanol treatment drastically inhibits liver regeneration after partial hepatectomy, the exact mechanisms involved remain obscure. On the other hand, it is known that early carbohydrate administration promotes a more successful restoration of the liver mass. Therefore, carbohydrate administration could be an experimental approach for studying ethanol action on the regenerating liver. In rats subjected to two-thirds partial hepatectomy, ethanol was administered alone or in combination with a variety of carbohydrates (glucose, fructose, glucose plus fructose, sucrose and maltose). In liver samples, regeneration parameters and histological assessment were performed. Blood ethanol and metabolites reflecting liver function were assayed. Ethanol intake strongly decreased the incorporation of [3H]thymidine into liver DNA, the concentration of DNA/g of tissue, and thymidine kinase activity. In this group, severe alterations in cell structure (i.e. abundant fat droplets and abnormal mitochondria) were found. Carbohydrates readily improved the survival rate of ethanol-intoxicated hepatectomized rats. Sucrose was effective in reverting the ethanol-induced alterations in liver structure and the parameters of liver regeneration, and partially blocked the ethanol-induced alterations in serum levels of albumin, triacylglycerols and ammonia without modifying the blood levels and clearance of ethanol. Data suggest that the beneficial action of sucrose might be related to an adequate supply of energetic sources at early times of liver regeneration, rather than altering ethanol bioavailability. Thus, the present model could be an experimental approach for studying the metabolic alterations involved in the ethanol-induced inhibition of the liver regeneration.

Ammonia↗

Expression patterns and action analysis of genes associated with hepatitis virus infection during rat liver regeneration.

AIM: To study the action of hepatitis virus infection-associated genes at transcription level during liver regeneration (LR). METHODS: Hepatitis virus infection-associated genes were obtained by collecting the data from databases and retrieving the correlated articles, and their expression changes in the regenerating rat liver were detected with the rat genome 230 2.0 array. RESULTS: Eighty-eight genes were found to be associated with liver regeneration. The number of genes initially and totally expressed during initial LR [0.5-4 h after partial hepatectomy (PH)], transition from G0 to G1 (4-6 h after PH), cell proliferation (6-66 h after PH), cell differentiation and reorganization of structure-function (66-168 h after PH) was 37, 8, 48, 3 and 37, 26, 80, 57, respectively, indicating that the genes were mainly triggered at the early stage of LR (0.5-4 h after PH), and worked at different phases. These genes were classified into 5 types according to their expression similarity, namely 37 up-regulated, 9 predominantly up-regulated, 34 down-regulated, 6 predominantly down-regulated and 2 up/down-regulated genes. Their total up- and down-regulation frequencies were 359 and 149 during LR, indicating that the expression of most genes was enhanced, while the expression of a small number of genes was attenuated during LR. According to time relevance, they were classified into 12 groups (0.5 and 1 h, 2 and 4 h, 6 h, 8 and 12 h, 16 and 96 h, 18 and 24 h, 30 and 42 h, 36 and 48 h, 54 and 60 h, 66 and 72 h, 120 and 144 h, 168 h), demonstrating that the cellular physiological and biochemical activities during LR were fluctuated. According to expression changes of the genes, their expression patterns were classified into 23 types, suggesting that the cellular physiological and biochemical activities during LR were diverse and complicated. CONCLUSION: The anti-virus infection capacity of regenerating liver can be enhanced and 88 genes play an important role in LR.

Animals↗

Differential lymphotoxin-beta and interferon gamma signaling during mouse liver regeneration induced by chronic and acute injury.

The liver regenerates after acute injury via hepatocyte cell division; during chronic injury, when hepatocyte replication is impaired or blocked, liver progenitor oval cells mediate liver regeneration. If both regeneration options are blocked in animal models, then liver failure and death ensues. The mechanisms underlying oval cell induction, proliferation, and subsequent liver regeneration remain poorly characterized. In particular, cell-signaling pathways that distinguish the alternative pathways are unknown. This study shows that in a mouse model, hepatic expression of lymphotoxin-beta (LTbeta) and interferon gamma (IFNgamma) transcripts is increased in response to the choline-deficient, ethionine-supplemented (CDE) diet, which induces oval cell-mediated liver regeneration. Oval cells express LTbeta and IFNgamma transcripts, contributing to the increased expression in the liver of mice fed the CDE diet. An attenuated oval cell response to such a diet was observed in LTbeta receptor-, LTbeta-, and IFNgamma-gene targeted mice. Loss of LTbeta and LTbeta receptor signaling reduced the number of oval cells expressing A6 and muscle pyruvate kinase. The lack of IFNgamma signaling reduced muscle pyruvate kinase(+), but not A6(+), oval cells. In contrast, partial hepatectomy suppressed LTbeta and IFNgamma transcripts. We also show that IFNgamma induces STAT-3 phosphorylation in an oval cell line. In conclusion, LTbeta, LTbeta receptor, and IFNgamma are involved in oval cell-mediated, but not hepatocyte-mediated, liver regeneration, and the absence of these pathways impairs the oval cell-dependent regenerative response.

Acute Disease↗

Rosiglitazone inhibits mouse liver regeneration.

The remarkable regenerative potential of the liver is well known. Recent investigations have shown that this regenerative response is impaired in mouse models of fatty liver disease. Other studies demonstrate that mice engineered for liver-specific overexpression of the peroxisome proliferator activated receptor gamma (PPARgamma) develop significant hepatic steatosis. These observations suggest that precise regulation of hepatic PPARgamma activity may be essential for normal liver regeneration. To test this hypothesis, we analyzed the effects of PPARgamma-activating thiazolidinediones on liver regeneration in the rodent partial hepatectomy model. Thiazolidinediones with different PPARgamma-activating potencies were administered to mice, and those mice were subjected to partial hepatectomy and analyzed for resulting effects on hepatocellular proliferation and signaling pathways important during normal liver regeneration. The results showed that thiazolidinediones suppress liver regeneration with efficacies that correlate with their relative PPARgamma-activating potencies. These studies provide the first evidence linking regulation of PPARgamma activity and the hepatic regenerative response.

Animals↗

Posttranscriptional regulation of gene expression in liver regeneration: role of mRNA stability.

The rentry of hepatocytes and nonparenchymal cells from the normal quiescent G0 phase into the cell cycle during liver regeneration after 70% partial hepatectomy results in the discrete modulation of mRNA transcripts for many different genes. The modulation of steady-state levels of transcripts for genes involved in hepatocyte growth and replication during liver regeneration indicates that gene expression is regulated not only transcriptionally but also posttranscriptionally. In fact, posttranscriptional control appears to be the primary mechanism of regulating gene expression after the first 3 h after partial hepatectomy. Alteration in transcript stability is a key posttranscriptional regulatory mechanism used by the regenerating liver to modulate the steady-state transcript levels of multiple genes. Even genes that are transcriptionally activated during liver regeneration exhibit posttranscriptional control at the level of transcript stability. Moreover, the abundance of mRNA binding proteins, as well as translational activity and rate of poly(A) tail removal, are modulated and appear to influence transcript stability during liver regeneration. However, alteration of transcript stability is not the sole posttranscriptional mechanism regulating steady-state levels. Posttranscriptional control also occurs at the level of alternative splicing, stabilization of heterogeneous nuclear (hn) RNA, and hnRNA processing. Moreover, the role of nucleocytoplasmic transport of mature mRNA during liver regeneration is still undefined. Thus, during liver regeneration gene expression is regulated at multiple levels after the initial synthesis of hnRNA. By understanding the role of posttranscriptional mechanisms in regulating steady-state transcript levels in an in vivo model of normal growth, we will begin to appreciate its role in the genesis of abnormal growth.

Animals↗

Regulation by thyroid hormone of the synthesis of a cytosolic thyroid hormone binding protein during liver regeneration.

To understand the regulation by thyroid hormone, 3,3',5-triiodo-L-thyronine (T3), of the synthesis of a cytosolic thyroid hormone binding protein (p58-M2) during liver regeneration, the synthesis of p58-M2 was evaluated. The synthesis of p58-M2 was measured by metabolic labeling of primary cultures derived from the regenerating liver of euthyroid, hypo- or hyperthyroid rats. During regeneration, the increase in the liver/body weight ratio is approximately 25% higher in hyper- than in hypothyroid rats. However, T3 has no effect on the rate of overall liver regeneration observed in four days. In mature liver, T3 increased the synthesis of p58-M2 by approximately 2.5-fold. During regeneration, however, the change in the synthesis of p58-M2 varied with the thyroid status. In euthyroid rats, the synthesis of p58-M2 continued to increase up to 2-fold during liver regeneration. In hyperthyroid rats, after an initial increase by 1.5-fold on day 1, the synthesis of p58-M2 subsequently declined during regeneration. In hypothyroid rats, the synthesis of p58-M2 remained virtually unchanged during regeneration. These results indicate that T3 regulates the synthesis of p58-M2 in mature and regenerating liver.

Animals↗

Liver regeneration is an angiogenesis- associated phenomenon.

OBJECTIVE: To investigate whether liver regeneration is an angiogenesis-associated phenomenon. SUMMARY BACKGROUND DATA: Angiogenesis is predominantly known for its pivotal role in tumor growth. However, angiogenesis could also play a role in physiologic processes involving tissue repair, such as liver regeneration. METHODS: Mice subjected to 70% partial hepatectomy were treated with human angiostatin (100 mg/kg body weight). Regeneration-induced hepatic angiogenesis was determined by assessing intrahepatic microvascular density using CD31 staining of frozen liver sections. Liver regeneration was evaluated by assessing wet liver weights and BrdU incorporation in DNA at regular intervals after partial hepatectomy. Possible direct effects of angiostatin on hepatocytes were studied by assessment of liver enzymes (ASAT, ALAT, bilirubin, lactate dehydrogenase), MTT assay (cytotoxicity), aminophenol production (metabolic function), and TUNEL (apoptosis). RESULTS: In a regenerating liver, microvascular density increased by 38%. Angiostatin significantly inhibited this response by 60%. In addition, angiostatin inhibited liver regeneration by 50.4% and 24.9% on postoperative days 7 and 14, respectively. In control mice liver weights regained normalcy in 8 days, whereas those in angiostatin-treated mice normalized after 21 days. In angiostatin-treated mice, the maximal BrdU incorporation was decreased and delayed. Direct adverse effects of angiostatin on cultured and in vivo hepatocytes were not observed. Angiostatin neither induced necrosis on hematoxylin and eosin staining nor affected serum levels of liver enzymes. CONCLUSIONS: Liver regeneration is accompanied by intrahepatic angiogenesis. Antiangiogenic treatment using angiostatin inhibits both phenomena. The authors conclude that liver regeneration is, at least in part, an angiogenesis-dependent phenomenon.

Analysis of Variance↗

Factors influencing liver regeneration following living-donor liver transplantation of the right hepatic lobe.

BACKGROUND: As a result of the shortage of cadaveric livers for adults, many institutes perform living-donor liver transplantation (LDLT) using right-lobe grafts. It is important to learn whether regeneration of the graft is compromised by division of middle hepatic vein (MHV) tributaries. Accordingly, we studied the effect on graft regeneration of transection of the MHV tributaries and other factors, including graft versus body weight ratio (GRBW). METHODS: Of 100 adult recipients having undergone right-lobe LDLT, 30 6-month survivors were studied. Liver regeneration was assessed by volumetry based on the computed tomography (CT). A regeneration index was defined as the ratio of the graft volume 6 months after LDLT to the preoperative value. The dominance of the MHV tributaries over the right hepatic vein in venous drainage of the anterior segment was evaluated by preoperative CT using a 5-point scale. RESULTS: The regeneration index of the posterior segment was significantly greater than that of the anterior segment (Wilcoxon signed rank test, P=0.01). The relatively poor regeneration of the anterior segment compared with the whole graft was associated with preoperatively dominant MHV tributaries (Spearman rank correlation: R=-0.44, P=0.01). The only significant determinant of the whole-graft regeneration, however, was GRBW (stepwise regression: Y=-0.80X+0.2, R(2)=0.70, P<0.0001). CONCLUSIONS: Despite deprivation of MHV tributaries, a graft will regenerate to meet the metabolic demand, and a smaller graft for the recipient is capable of regenerating to a greater extent.

Adolescent↗

Remodelling of calcium signalling during liver regeneration in the rat.

BACKGROUND/AIMS: During liver regeneration, a network of cytokines and growth factors interact with hepatocytes, helping to restore the liver mass and functions after partial tissue loss. Agonists that trigger Ca2+ signals in the liver contribute to this process, although little is known about calcium signalling during liver regeneration. RESULTS: We observed two phases in which the hepatocyte response to calcium-mobilising agonists was greatly reduced versus control cells at 24h and five days after partial hepatectomy. We found that both phases of hepatocyte desensitisation involved the down-regulation of cell surface receptors and the type II InsP3 receptor. Single cell studies with flash photolysis of caged InsP3 revealed that InsP3-mediated Ca2+ release was slower in regenerating hepatocytes at 24, 48 h and 5 days than in control cells. Also, the temporal pattern of vasopressin-elicited intracellular calcium oscillations studied on fura2-loaded cells was altered, with the duration of each Ca2+ peak being longer. Finally, we showed an association between hepatocyte desensitisation and progression through the cell cycle towards the S phase at 24 h after hepatectomy. CONCLUSIONS: Our study supports the remodelling of hepatocyte calcium signalling during liver regeneration, and that this change is partly linked with cell cycle progression.

Animals↗

Influence of epidermal growth factor on liver regeneration after partial hepatectomy in rats.

The role of epidermal growth factor on liver regeneration after partial hepatectomy in rats was investigated. After a 70% hepatectomy in rats, the concentration of epidermal growth factor in portal venous blood was unchanged compared with unoperated controls. However, small amounts of epidermal growth factor could be identified in portal venous blood after intestinal instillation of epidermal growth factor. Brunner's glands and the submandibular glands secrete epidermal growth factor. Extirpation of Brunner's glands decreased liver regeneration, whereas removal of the submandibular glands had no effect on liver regeneration. Epidermal growth factor antiserum reduced liver regeneration significantly. Oral or s.c. administration of epidermal growth factor had no effect on liver regeneration, whereas epidermal growth factor enhanced the effect of insulin and glucagon on liver regeneration. The results suggest that endogenous epidermal growth factor participates in stimulation of liver regeneration after partial hepatectomy in rats. Epidermal growth factor given together with insulin and glucagon had a synergistic effect on liver regeneration which suggests that liver regeneration in the rat is controlled by multiple regulatory peptides.

Animals↗

Studies on regenerating liver and hepatoma plasma membranes--I. Lipid and protein composition.

1. Plasma membranes were isolated from normal liver, Morris hepatoma 7288C and regenerating liver, 6, 15, 24, and 48 hr after partial hepatectomy. 2. The cholesterol/phospholipid ratio was lower in regenerating liver 6 hr after partial hepatectomy (0.51) compared to the sham control (0.68), returning to normal after 15 hr. This was accompanied by a small increase in palmitic acid (16:0). There were no other changes in the lipid composition in regenerating hepatocytes in the first 48 hr after partial hepatectomy. 3. Analysis of lipid composition showed a higher cholesterol/phospholipid ratio in the hepatoma plasma membrane compared to normal liver accompanied by an increase in saturation of the fatty acyl groups of the phospholipids. There were also significant changes in the phospholipid classes. 4. There was no change in the two-dimensional electrophoretic profile of membrane proteins in the early stages of liver regeneration, however hepatoma membranes showed significant differences in protein profile. 5. These changes in the lipid composition of the hepatoma plasma membrane would have the effect of decreasing the average fluidity of the membrane and together with the changes in protein composition may be significant in the altered growth of the hepatoma. Changes in the lipid composition of the hepatocyte plasma membrane early in liver regeneration may reflect the onset of renewed cell division.

Animals↗