Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “HEPATECTOMY”

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
PubMed2004

Apoptosis induced by 5-(N,N-hexamethylene)-amiloride in regenerating liver after partial hepatectomy.

The effects of a specific inhibitor of the Na+/H+ exchanger, 5-(N,N-hexamethylene)-amiloride (HMA), on liver regeneration after partial hepatectomy were investigated. A single injection of HMA inhibited DNA synthesis and caused apoptosis in regenerating liver. Characteristic DNA fragmentation was observed at 4 h after partial hepatectomy with HMA-injection. The activity of Jun N-terminal kinase (JNK) increased to a maximal level at 15 min after partial hepatectomy in HMA-injected rats, while it was not detected until 30 min in the control. Western blot analysis revealed that the injection of HMA markedly increased c-Jun and phosphorylated c-Jun protein levels at 30 min after partial hepatectomy. An increase in p53 was also observed at 30 min after the HMA-injection and was followed by the upregulation of p21WAF1/CIP1 protein expression at 1 h after partial hepatectomy. These results suggested that HMA induced apoptosis accompanied by the activation of JNK and the upregulation of c-Jun, p53 and p21WAF1/CIP1 expression at an early stage of liver regeneration.

Amiloride↗
PubMed2006

Recovery from liver failure after hepatectomy for hepatocellular carcinoma in cirrhosis: meaning of the model for end-stage liver disease.

BACKGROUND: Hepatectomy for hepatocellular carcinoma in cirrhosis is followed by an impairment of liver function that can lead to patient death. The model for end-stage liver disease (MELD) is considered an index of hepatic functional reserve, and its assessment on postoperative course may properly identify individuals at risk of liver failure. STUDY DESIGN: Two hundred hepatectomies for hepatocellular carcinoma in cirrhosis were reviewed. Irreversible postoperative liver failure was defined as an impairment of liver function after hepatectomy that led to patient death or required transplantation. The MELD scores at postoperative days (POD) 1, 3, 5, and 7 were calculated and kinetics of changes investigated with t-test; logistic regression was applied to identify predictive variables of postoperative liver failure. RESULTS: Kinetics of postoperative MELD score showed an impairment of liver function between PODs 1 and 3; 185 patients in whom postoperative liver failure did not develop showed a considerable decrease in MELD score between PODs 3 and 5 (11.9+/-2.8 and 10.6+/-2.4, respectively, p<0.001). On the contrary, 15 patients, who experienced the event, showed an increase in MELD score between PODs 3 and 5 (18.2+/-3.9 and 18.3+/-3.6, respectively; p=0.845). Multivariate analysis showed preoperative MELD score (p<0.001), major hepatectomy (p=0.028), and MELD score increase between PODs 3 and 5 (p=0.011) as independent predictors of irreversible postoperative liver failure. Scores are reported as mean+/-SD. CONCLUSIONS: Recovery from liver impairment after hepatectomy for hepatocellular carcinoma in cirrhosis starts from POD 3; MELD scores increasing between PODs 3 and 5 may identify patients at risk of liver failure and represents the trigger for beginning intensive treatment or evaluating salvage transplantation.

Aged↗
PubMed2005

Hepatic gene induction in murine bone marrow after hepatectomy.

BACKGROUND/AIMS: Bone marrow cells are highly plastic and differentiate into various cell types, including hepatocytes. To explore the mechanisms underlying these processes, we focused on the initial responses of bone marrow to hepatectomy, using a mouse model. METHODS: To evaluate hepatic differentiation in bone marrow cells we measured hepatocyte-related gene expression in mice undergoing partial hepatectomy with or without pretreatment for 1 week with 2-acetyl aminofluorene (AAF). RESULTS: Hepatectomy induced several genes related to early hepatic differentiation in bone marrow. Expression of these genes was enhanced by the administration of AAF, whereas genes specific for mature hepatocytes were not detected. We characterised the bone marrow cell population expressing hepatocyte differentiation genes. alpha-fetoprotein mRNA was induced in Lin- and either CD34+, c-kit+, Sca-1+, CD49f+ or CD45+ cells. The genes upregulated in the liver after AAF treatment and hepatectomy were identified using oligonucleotide microarrays. These included genes associated with the acute phase response. Dexamethasone inhibited the expression of early hepatic differentiation genes in the bone marrow of AAF/PHx mice. CONCLUSIONS: Early hepatic differentiation genes were induced in bone marrow in response to hepatectomy, especially when regeneration of the remnant liver was suppressed. Circulating signals generated in the AAF/PHx liver might activate this differentiation.

2-Acetylaminofluorene↗
PubMed2005

N-acetylcysteine attenuates bacterial translocation after partial hepatectomy in rats.

BACKGROUND: Translocating enteric bacteria have been suggested as playing a major role in the development of infections after partial hepatectomy. We investigated the effect of N-acetylcysteine (NAC) on bacterial translocation (BT) and intestinal mucosa as the first line of defense against BT. MATERIALS AND METHODS: We compared four groups of eight Sprague-Dawley male rats each: sham, control (partially hepatectomized), partial hepatectomy plus preoperative single-dose NAC, and a fourth that received partial hepatectomy with a preoperative single-dose NAC plus treatment with NAC for 2 days. Microorganism counts of tissues, lung injury score, lung tissue glutathione, and malondialdehyde levels and microscopy of intestinal mucosa were studied at the end of 48 h. RESULTS: Microorganism count in the lung and mesenteric lymph node cultures and lung injury score were significantly higher in the control group when compared with the sham, third, and fourth groups (lung: 9919.6 versus 0.0, 2912.9, 1550.0 cfu/g tissue; mesenteric lymph nodes: 8458.3 versus 0.0, 89.0, 88.9 cfu/g tissue; lung injury score: 3.25 versus 0.5, 1.13, 1.75). In the control group, the villous height of the distal ileal mucosa was significantly shorter than the sham group (65.25 versus 75.25 microm) and the difference from groups 3 and 4 was not statistically significant. Neutrophil infiltration in the distal ileal mucosa of the control group was significantly higher than the sham, third and fourth groups (3.13 versus 0.25, 0.38 and 1.0). CONCLUSIONS: The parenteral use of NAC attenuates bacterial translocation after partial hepatectomy in rats. Attenuation of the lung injury after partial hepatectomy in NAC-treated groups might be attributable to both anti-inflammatory effect and the effect on BT.

Acetylcysteine↗
PubMed2004

Immediate and long-term outcomes of hepatectomy for hepatolithiasis.

OBJECTIVE: The aim of this study was to evaluate the perioperative and long-term results of hepatectomy for hepatolithiasis. PATIENTS AND METHODS: Immediate and long-term outcomes of 103 consecutive patients with hepatolithiasis who underwent hepatectomy from 1989 to 2001 were analyzed. Immediate outcomes included stone clearance rate, operative morbidity, and mortality. Long-term results included stone recurrence rate and survival. RESULTS: The immediate stone clearance rate was 90%, and the final stone clearance rate was 98% after subsequent choledochoscopic lithotripsy by cutaneous stoma or T-tube route. The operative morbidity and hospital mortality rates were 28% and 2%, respectively. Multivariate analysis showed that right hepatectomy (P=.006) and preoperative hyperbilirubinemia (P=.038) were predictive of postoperative complications. Ten patients (10%) had associated cholangiocarcinoma (four known preoperatively) at the time of hepatectomy. With a median follow-up of 56 months (range 6-158), recurrent stones developed in eight patients and cholangiocarcinoma developed in three patients (range: 7-30 months postoperatively). Sixteen patients had died during the follow-up period, none of recurrent cholangitis. Cholangiocarcinoma was the only significant prognostic factor of long-term survival by Cox regression analysis. CONCLUSIONS: Hepatectomy is a safe and effective treatment for hepatolithiasis, with a high immediate stone clearance rate and a low long-term stone recurrence rate. The presence of associated cholangiocarcinoma is the main factor compromising long-term survival in patients with hepatolithiasis.

Adult↗
PubMed2006

Arsenite induces apoptosis in hepatocytes through an enhancement of the activation of Jun N-terminal kinase and p38 mitogen-activated protein kinase caused by partial hepatectomy.

To investigate the effects of arsenite on cell proliferation and the signal transduction in hapatocytes in vivo, rats received a single injection of sodium arsenite immediately after partial hepatectomy. Characteristic DNA fragmentation was observed at 4h after the arsenite-injection in partially hepatectomized liver, while it was not detected either in the control (partial hepatectomy only) or arsenite-injected normal (without partial hepatectomy) liver. The effect of the arsenite-injection on the activation of extracellular signal-regulated kinase (ERK) was not observed in the normal or the partially hepatectomized liver. The activity of p38 mitogen-activated protein kinase (MAPK) markedly increased after 15min to 2h after the arsenite-injection in partially hepatectomized liver while no or a less increase was observed in the arsenite-injected normal or the control, respectively. The Jun N-terminal kinase (JNK) was activated to a maximal level, about six-fold the maximum of the control, at 15min after the injection with partial hepatectomy. The arsenite-injection markedly increased the phosphorylated forms of c-Jun and ATF-2 and the protein levels of c-Jun, p53 and p21(WAF1/CIP1) in the partially hepatectomized liver. These results suggested that arsenite induced apoptosis in the hepatocytes in vivo, through the enhancement of the activation of JNK and p38 MAPK caused by partial hepatectomy and the p53-dependent p21(WAF1/CIP1) protein expression.

Animals↗
PubMed2004

Effects of pirfenidone on endotoxin-induced liver injury after partial hepatectomy in rats.

BACKGROUND: In living donor liver transplantation, restrictions on graft size are a serious obstacle to expand indications for adult recipients. The sequence of gram-negative infection, septicemia, and multiple-organ failure is a common cause of early mortality after liver transplantation. An effective therapy has not been established for endotoxemia following extended hepatectomy in donors or small-for-size grafts in recipients. Pirfenidone (PFD), a new experimental antifibrotic agent, was used to ameliorate on endotoxin-induced liver injury following partial hepatectomy. METHODS: Male Sprague-Dawley rats were intravenously administered lipopolysaccharide (LPS) 48 hours after 70% hepatectomy. Prior to LPS administration, PFD (300 mg/kg) or its vehicle (0.5% carboxymethylcellulose) was given orally twice. RESULTS: The survival rate of the PFD-treated group was markedly improved compared with that of the controls. PFD prevented the increases in the activities of serum enzymes (aspartate transaminase [AST], alanine transaminase [ALT], and lactate dehydrogenase [LDH]) and total bilirubin. The serum and liver tissue levels of inflammatory cytokines, such as tumor necrosis factor-alpha, interleukin-1beta, interferon-gamma, and interleukin-6, were significantly lower among the PFD than the control group. Furthermore, the degree of necrosis in the remnant liver was significantly decreased in the PFD-treated rats compared with controls. CONCLUSION: These results indicate that PFD alleviates endotoxin-induced liver injury after partial hepatectomy through the inhibition of production of inflammatory cytokines in the residual liver. PFD may be useful to prevent endotoxin-induced liver injury after hepatectomy.

Animals↗
PubMed2004

Functional hepatic regeneration following hepatectomy using galactosyl-human serum albumin liver scintigraphy.

In extended hepatectomy and liver transplantation, accurate estimation of functional hepatic regeneration is more important than volumetric regeneration. We investigated the usefulness of measuring the functional hepatic volume by 99m-technetium galactosyl-human serum albumin scintigraphy (GSA). Extended hepatectomy was performed in 32 patients. These patients were divided into subgroups with or without chronic hepatitis or cirrhosis. Functional hepatic volume GSA scintigraphy (GSA-LV) and determination of hepatic volume by CT (CT-LV) measurements were performed preoperatively, at 2 and 4 weeks and at 3 and 6 months after surgery. The preoperative GSA-LV values were significantly correlated with the hepatocyte volume and the 15-minute retention rate of indocyanine green (ICGR15). Similarly, the hepatocyte volume correlated well with the CT-LV and ICGR15. However, the CT-LV correlated only with the ICGR15. Recovery of the GSA-LV was delayed, and about 90% of the volumetric and functional regeneration was observed within 6 months after the hepatectomy. In contrast, the CT-LV in patients with normal liver remnants returned to approximately 90% of the initial volume within 1 month after the hepatectomy, whereas patients with injured livers regeneration showed gradual recovery to approximately 80% of the preoperative value by 6 months after hepatectomy. We conclude that measurement of functional hepatic volume using the GSA-LV is useful to evaluate hepatic function based on hepatocyte volume.

Carcinoma, Hepatocellular↗
PubMed1999

Changes in hepatic venous oxygen saturation related to the extent of regeneration after partial hepatectomy in rats.

BACKGROUND: Changes in hepatic oxygen metabolism in relation to the extent of liver regeneration are expected after partial hepatectomy. There are few reports, however, about hepatic oxygen metabolism during liver regeneration. In this study, we evaluated changes in hepatic oxygen metabolism related to the regeneration rate, and the relationship between hepatic venous oxygen saturation (Shvo2) and liver regeneration after partial hepatectomy. METHODS: The work was done using 50% hepatectomized rats with continuous infusion of octreotide for inhibition of liver regeneration or with saline as control. The hepatic hemodynamics, oxygen metabolism, and Shvo2 levels as well as the regenerating liver status were evaluated for 3 days after hepatectomy. RESULTS: Administration of octreotide resulted in a significant reduction of the regenerating liver weight on days 1 and 3 after hepatectomy compared with the control group. Significantly decreased DNA synthesis and proliferating cell nuclear antigen labeling index were also found on day 1. Meanwhile, hepatic oxygen consumption (HVO2) and oxygen extraction ratio were significantly decreased in the octreotide-treated group on day 1. In contrast, the Shvo2 levels in the octreotide-treated group were significantly higher than those in the control group, and were inversely correlated with the HVO2. CONCLUSION: The remnant liver demands an increased amount of oxygen in relation to the extent of regeneration, and changes in the Shvo2 are inversely correlated with the HVo2. Therefore, monitoring the Shvo2 could be useful for estimating liver regeneration after partial hepatectomy.

Animals↗
PubMed2003

High expression of the CD14 gene and interleukin-1beta gene in the liver and lungs of cirrhotic rats after partial hepatectomy.

BACKGROUND: A hepatic resection is invasive for cirrhotic patients because postoperative complications, such as hepatic disturbance sometimes resulting in hepatic failure and pulmonary disturbances, are frequent and serious. We investigated here the alteration of the CD14 and inflammatory cytokine genes expressed in the liver and lungs after partial hepatectomy (PH) of a cirrhotic rat model to help elucidate the pathophysiological change occurring during the postoperative course of hepatectomized cirrhotic patients. MATERIALS AND METHODS: Wistar rats were orally administrated carbon tetrachloride once a week for 14 weeks to induce liver cirrhosis. In comparison with cirrhotic and normal rats, we analyzed the expression of the CD14, tumor necrosis factor-alpha, and interleukin (IL)-1beta genes in remnant liver and whole lung tissue during 48 h after 30% partial hepatectomy with Northern blottings and measured asparatate aminotransferase (AST) in serum for evaluation of postoperative hepatic injury. Gadolinium chloride (GdCl3; 7 mg/kg body weight) was intravenously injected 24 h before partial hepatectomy to suppress Kupffer cells (KC) activation. RESULTS: The expression of the CD14 and IL-1beta genes moderately increased at 6 h and peaked at 12 h in parallel with the time course of AST values after PH only in cirrhotic rats. GdCl(3) significantly inhibited the elevation of AST similar to the inhibition of the expression of the CD14 and IL-1beta genes after PH. In addition, the expression of these genes showed marked enhancement in the lungs of the cirrhotic hepatectomy model. CONCLUSIONS: KC activation was responsible for hepatic injury after PH, and the CD14 system appeared to be an early trigger for KC activation followed by induction of inflammatory cytokine IL-1beta synthesis leading to hepatic injury. Furthermore, the CD14 system was suggested to participate in respiratory disturbances after hepatectomy in cirrhosis.

Animals↗
PubMed2004

Bleeding during hepatectomy can be reduced by clamping the inferior vena cava below the liver.

BACKGROUND: Control of blood loss is a crucial problem during hepatectomy. Bleeding from the inflow system can be controlled by the Pringle maneuver or selective vascular occlusion. Bleeding from the outflow system is closely related to central venous pressure (CVP). Therefore, in this study, we evaluated whether vascular outflow control by clamping the inferior vena cava (IVC) below the liver (IVC clamping) during hepatectomy is a safe and effective method to reduce blood loss and CVP. METHODS: We reviewed the outcomes of 103 consecutive patients whose CVP values were >5 cm H(2)O and who had undergone right or left hemihepatectomy between 1995 and 2000. Forty-seven patients who underwent hepatectomy with IVC clamping (Group A) between 1998 and 2000 were compared with the previous 56 patients who underwent hepatectomy without IVC clamping between 1995 and 1997 (Group B). RESULTS: The CVP decreased by 3.7 cm H(2)0 after IVC clamping. Estimated blood loss was 910 mL in Group A and 1177 mL in Group B. (P=.008) No severe renal or cardiovascular damage occurred after IVC clamping. CONCLUSIONS: IVC clamping is very effective in reducing blood loss during hepatectomy when the CVP is elevated and cannot be reduced pharmacologically or by fluid restriction.

Aged↗
PubMed2002

Von Willebrand factor in plasma and in liver tissue after partial hepatectomy in the rat.

BACKGROUND/AIMS: Von Willebrand factor (vWf) is found in high levels in plasma of patients with acute and chronic liver disease. The role of vWf in liver injury and repair is unknown. We studied the effect of liver mass and remodeling on plasma and tissue vWf after partial hepatectomy. METHODS: Rats were sacrificed postoperatively at intervals ranging from 60 min to 5 days, and vWf plasma levels were measured by enzyme-linked immunosorbent assay, using rabbit anti-human vWf, and by immunoperoxidase on cryosections, using rabbit anti-vWf/factor VIII. Northern blot hybridization was prepared with a complementary DNA specific to human vWf. RESULTS: vWf plasma levels increased early after sham operation and after 70% partial hepatectomy. The highest levels were reached at 24 h, remaining high for 5 days. Immunostaining showed intense staining of sinusoidal lining cells 4 h after partial hepatectomy, remaining so for 5 days. Non-significant changes in overall liver messenger RNA expression of vWf were seen over 5 days in sham operation and partial hepatectomy. CONCLUSIONS: After partial hepatectomy, plasma vWf is increased, probably due to both acute-phase reaction and decreased degradation. An increase in sinusoidal vWf immunostaining may suggest a role for this factor in tissue remodeling.

Animals↗
PubMed2003

Kupffer cells modulate splenic interleukin-10 production in endotoxin-induced liver injury after partial hepatectomy.

BACKGROUND/AIMS: This study was conducted to investigate the implication of Kupffer cells and the spleen in interleukin (IL)-10 production in endotoxin-induced liver injury after hepatectomy. METHODS: Rats were divided into five groups: the S group, sham-operation; the SG group, sham-operation followed by intravenous gadolinium chloride (GdCl(3): 7 mg/kg) administration to inhibit Kupffer cell function; the H group, two-thirds hepatectomy; the HG group, hepatectomy and subsequent GdCl(3) administration; the HGS group, hepatectomy and splenectomy with GdCl(3) administration. Lipopolysaccharide (1.5 mg/kg) was intravenously administered for each group 48 h after surgery. RESULTS: GdCl(3) treatment significantly suppressed the elevation of plasma tumor necrosis factor (TNF)-alpha levels by lipopolysaccharide administration with completely inhibited induction of hepatic TNF-alpha and IL-10 mRNAs. In the HG group, marked increase in plasma IL-10 levels associated with enhanced splenic IL-10 mRNA was observed 1 h after lipopolysaccharide administration when compared to those in the H and HGS groups. Plasma TNF-alpha/IL-10 ratio 1 h after lipopolysaccharide administration was higher in the order of H, HGS and HG groups. Hepatic parenchymal damage and the 24-h mortality were lowest in group HG, followed by groups HGS and H. CONCLUSIONS: Kupffer cells after hepatectomy may aggravate endotoxin-induced liver injury via down-regulation of IL-10 production in the spleen.

Alanine Transaminase↗
PubMed1997

Hepatic expression of regeneration marker genes following partial hepatectomy in the rat. Influence of 1,25-dihydroxyvitamin D3 in hypocalcemia.

BACKGROUND/AIMS: Vitamin D (D) depletion is a common feature of chronic liver diseases. In past years, disturbances in calcium metabolism involving inadequate D and parathyroid hormone status have been reported to significantly impair the hepatic regeneration process following partial hepatectomy in the rat. The purpose of this study was to investigate how hypocalcemia and D deficiency affect specific cell markers of hepatic compensatory growth. METHODS: Steady-state mRNA levels of gene markers of the regeneration process were investigated following 2/3 partial hepatectomy. The response of hypocalcemic D-depleted rats was compared to that of animals whose calcium status had been normalized by repletion with the active D hormone 1,25-dihydroxyvitamin D3 (1,25(OH)2D3). RESULTS: The transcript for the major hepatic mitogen HGF increased in both groups after partial liver resection but the increase was significantly lower as well as delayed in livers obtained from calcium deficient rats in the prereplicative phase of the regeneration process. TGF alpha mRNA levels were also found to be significantly lower in calcium deficient rats at all time-points following partial hepatectomy, while the relative behavior of the tandem TGF alpha-EGFR indicated an early dominant effect in normocalcemic 1,25(OH)2D3-repleted animals. HGF-c-met mRNA levels also indicated that the 1,25(OH)2D3-repleted animals reacted more promptly to the regeneration stimuli. Indeed, while relative (1,25(OH)2D3/D-Ca- ratio) maximum mRNA levels were observed 12 h following liver resection in 1,25(OH)2D3-treated animals, relative peak levels were only apparent 24 h post-surgery in hypocalcemic rats. Maximum cyclin D1 (a marker of the G1 phase of the cell cycle) mRNA occurred between 8-18 h after partial hepatectomy in 1,25(OH)2D3-repleted animals to return to base-line value thereafter, but in hypocalcemic rats the transcript levels remained significantly below 1,25(OH)2D3-repleted animals during the prereplicative period with increases above initial values between 12-24 h post-surgery. Both cyclin A (an S phase marker) transcripts (1.8 and 2.9 kb) were influenced by the regeneration process. The transcripts significantly and sharply increased in hypocalcemia between 30-36 h following partial hepatectomy to decrease thereafter, while the increase was observed between 24-30 h, and at 48 h (1.8 kb) in 1,25(OH)2D3-repleted animals. Liver weight recovery was also found to be decreased in D-depleted rats over the 48 h period of observation. CONCLUSIONS: Our data further confirm the presence of an impaired regeneration process in hypocalcemia of D deficiency which seems to be associated with gene markers indicating an inefficient transit across the G1 phase of the cell cycle.

Animals↗
PubMed1990

Ultrastructural study of hepatic regeneration following one-lobe, two-lobe, and subtotal hepatectomy in the rat.

The sequential and comparative ultrastructural features of regenerating rat liver following one-lobe, two-lobe, and subtotal hepatectomy were studied. All three groups demonstrated glycogen depletion at the 12 h post-hepatectomy interval with reaccumulation occurring at 24 h in the first two groups but not until 72 h in the subtotal hepatectomy group. Other hepatocellular alterations attributed to regenerative activity were similar in the three groups, however the onset and magnitude of those changes occurring in the two-lobe and subtotally hepatectomized rats differed significantly from those alterations occurring in the one-lobe hepatectomy group. These changes were characterized by a greater and more prolonged mitotic activity, increased proliferation of RER and smooth endoplasmic reticulum (SER), and by increased Golgi bodies. These two groups also manifested greater hepatocellular accumulation of phagolysosomes, myelin figures, and lipid bodies when compared with the one-lobe hepatectomy group.

Animals↗
PubMed1985

Inducibility of the hepatic microsomal monooxygenase system experimentally reduced to a minimum amount/activity. Effect of hypophysectomy, partial hepatectomy and phenobarbital/toluene treatment on the hepatic polysubstrate monooxygenase system in rats.

Sham-operated, hypophysectomized, partially hepatectomized and hypophysectomized + partially hepatectomized groups of CFY rats were treated with phenobarbital (40 mg/kg/day) per os or physiological saline once a day, or toluene-vapour (inhalation: 4,000 mg/m3, 8 h/day), for 3 days. The polysubstrate monooxygenase (PSMO) system of the liver was induced by phenobarbital after all kinds of surgical interventions. Inducibility of the enzyme system was the highest in the group with combined hypophysectomy + partial hepatectomy and decreased in order in the groups with partial hepatectomy, hypophysectomy and sham-operation. The relative cytochrome P-450 content (quantity of cytochrome P-450/100 g b.w.) was the lowest after combined operation, higher in partially hepatectomized and hypophysectomized animals and it was the highest in the sham-operated group. Hypophysectomy after partial hepatectomy seems to inhibit hepatic regeneration and to increase the inducibility of the enzyme by phenobarbital, at the same time. Phenobarbital treatment brought about SER proliferation in a part of liver cells, in each group. In case of repeated liver damage due to the consequences of hypophysectomy, partial hepatectomy, phenobarbital administration, a group of the liver cells responds to the first, another to the second, but even after the third injury a group of the liver cells maintained its regular structure. The hypothetical hepatotoxic effect of toluene, a widely used industrial solvent, has been tested. Hepatotoxicity has been excluded. The minimum non-specific hepatotoxic effect of the solvent was not augmented by either partial hepatectomy or hypophysectomy, or by the combination of the two. In all the experimental groups toluene increased the hepatic cytochrome P-450 level and induced a moderate increase in SER. Inducibility of the enzyme system after toluene inhalation was similar to that of the enzyme system after phenobarbital treatment in each group.

Animals↗
PubMed1998

Effect of folic acid on thymidylate synthase and thymidine kinase in regenerating rat liver after partial hepatectomy.

The effects of folic acid on liver regeneration after partial hepatectomy were investigated. The injection of folic acid inhibited the increases in the activities of thymidylate synthase and thymidine kinase in regenerating rat liver at 24 h after partial hepatectomy, with a concomitant reduction in DNA content. Northern blot analysis showed that this inhibition was due to the delay of the elevation of the mRNA levels of thymidylate synthase and thymidine kinase after partial hepatectomy. At 48 and 72 h, after partial hepatectomy, the thymidylate synthase activities in the folic acid injected rats increased to about 1.9- and 1.7-fold the corresponding control level, respectively, while thymidine kinase activities were similar to the control. Immunoblotting assay indicated that the increases in the thymidylate synthase activity at 48 and 72 h after partial hepatectomy were caused by a three fold increase in its protein level. Folic acid suppressed chymotryptic hydrolysis of thymidylate synthase. These suggest that folic acid increases the protein level of thymidylate synthase, at least in part, through protection against proteolysis.

Animals↗
PubMed1999

Mitochondrial oxidative alterations following partial hepatectomy.

Mitochondria, isolated from rat livers during the early phase of liver regeneration (7-24 h after partial hepatectomy), show: (i) decrease in the rate of ATP synthesis; (ii) increase of malondialdehyde and of oxidized protein production; (iii) decrease of the content of intramitochondrial glutathione and of protein thiols on mitochondrial proteins; (iv) increase of the glutathione bound to mitochondrial proteins by disulfide bonds. These observations suggest an increase of production of oxygen radicals in liver mitochondria, following partial hepatectomy, which can alter the function of the enzymes involved in the oxidative phosphorylation. Blue-native gel electrophoresis of rat liver mitochondria, isolated after partial hepatectomy, shows, during the early phase of liver regeneration (0-24 h after partial hepatectomy), a progressive decrease of the content of F0F1-ATP synthase complex. The amount of glutathione bound to the F0F1-ATP synthase, electroeluted from the blue-native gels, progressively increased during the early phase of liver regeneration. It is concluded that partial hepatectomy causes mitochondrial oxidative stress that, in turn, modifies proteins (such as F0F1-ATP synthase) involved in the mitochondrial oxidative phosphorylation.

Animals↗