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Query: EC:2.6.1.2 (
alanine aminotransferase
)
26,722
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
An accurate serologic measure of hepatic function would be clinically useful in selecting donors for liver transplantation. An experimental model that incorporates varying lengths of total hepatic warm
ischemia
with reperfusion injury was utilized to compare serologic parameters and mitochondrial performance of oxidative phosphorylation in predicting hepatocellular injury. Monoethylglycinexylidide (MEGX) formation following bolus intravenous lidocaine injection was found to be significantly decreased (P < 0.0001) at all periods of
ischemia
when compared to that in nonischemic controls. A serum MEGX level of < 50 micrograms/liter suggested severe hepatic damage. No correlation was found between MEGX level and liver viability as measured by animal survival. Serum transaminase (AST and
ALT
) levels demonstrated progressive, nonsignificant elevations with increasing length of
ischemia
(P = 0.0779 at the maximum ischemic time). Polarographic measurements of mitochondrial oxidative phosphorylation did not reveal a significant alteration in subcellular metabolism with prolonged ischemic time. These data highlight the comparative sensitivity of MEGX formation as an early quantitative measurement of hepatocellular injury during warm
ischemia
, although it was not predictive of organ viability.
...
PMID:Monoethylglycinexylidide formation as an independent measure of warm hepatic ischemia and reperfusion injury. 764 94
The effects of warm
ischemia
were investigated in obese Zucker rats with severe hepatic steatosis in order to develop a nontransplant fatty liver
ischemia
model. Obese (Ob) and lean (Ln) Zucker rats were subjected to in vivo partial hepatic warm
ischemia
of 45 or 90 min. Injury was assessed by serum
alanine aminotransferase
, animal survival, and liver histology. Liver lipids were quantified in control animals. After 90-min
ischemia
and 2-hr reperfusion, liver malondialdehyde was measured and neutrophils in 12 microscopic fields were counted after esterase staining. After 45 and 90 min of
ischemia
, Ob animals had significantly higher
alanine aminotransferase
at 1-hr and 24-hr reperfusion, compared with Ln animals (P < 0.01). After 90 min of
ischemia
, none of the Ln and 8/9 Ob animals died within 48 hr (P < 0.01). Histologically, Ob animals had more hepatocyte necrosis than did Ln animals. Hepatic neutral and phospholipid content (mg/g) in Ob versus Ln animals was 45.2 +/- 2.6 versus 8.2 +/- 0.7 (P < 0.01) and 36.2 +/- 1.9 versus 27 +/- 2.2 (P < 0.05), respectively. After reperfusion, liver malondialdehyde content increased significantly in Ob animals (8.5 +/- 0.4 vs. 12.3 +/- 0.8 pM/mg protein; P < 0.05), but not in Ln animals. Neutrophils, scant in control livers, increased significantly (P < 0.01) after
ischemia
/RP, but it increased to a similar degree in Ob and Ln animals. Obese Zucker rats with hepatic steatosis are more susceptible to warm
ischemia
/reperfusion injury than lean animals, and lipid peroxidation may be an important contributory mechanism. Further studies in this model might help to investigate the human problem.
...
PMID:Studies of hepatic warm ischemia in the obese Zucker rat. 770 52
Effect of LipoPGE1 on liver injury caused by
ischemia
-reperfusion were compared with that of PGE1-CD, cyclodextrin clathrated PGE1, in rats. LipoPGE1 (10 micrograms/kg) and PGE1-CD (10 micrograms/kg) were gradually injected into the portal vein 5 min both prior to
ischemia
and prior to reperfusion. In only the group receiving injections of vehicle alone, rats died within 2 days after the episode of 90-min liver
ischemia
. The survival rate of all rats treated with LipoPGE1 was higher than that of rats who received vehicle alone, which indicates that LipoPGE1 pretherapy improved the survival of rats after liver
ischemia
-reperfusion. LipoPGE1 markedly suppressed elevations of GOT,
GPT
, and LDH, lipid peroxide and aromatic amino acid levels in the plasma caused by
ischemia
-reperfusion of the liver. When animals were given a single dose of LipoPGE1 prior to reperfusion, LipoPGE1 also suppressed elevations of GOT,
GPT
, LDH and lipid peroxide levels caused by 30-min of liver
ischemia
followed by 12-hr reperfusion. These suppressive effects with LipoPGE1 were stronger than those of PGE1-CD. These findings suggest that LipoPGE1 may have therapeutic applications in the treatment of hepatic injury.
...
PMID:[Protective effects of LipoPGE1, prostaglandin E1 incorporated in lipid microspheres, against liver injury caused by ischemia-reperfusion]. 773 95
This study aimed at analyzing the involvement of platelet activating factor (PAF) in
ischemia
/reperfusion injury (I/R) of the liver. Male Wistar rats under pentobarbital anesthesia were subjected to 60 min of normothermic
ischemia
of the left and median liver lobes, followed by 30 min of reperfusion in vivo. Blood pressure and body temperature were controlled throughout the experiment. Preischemic injection of a specific PAF antagonist (BN52021, 5 mg/kg body mass) resulted in significant reduction of postischemic enzyme loss into the serum from the vascular endothelium (purine nucleoside phosphorylase: 56.9 +/- 11.4 vs 86.6 +/- 20.4 U/l**) and the hepatic parenchyme (
alanine aminotransferase
: 176 +/- 60 vs 519 +/- 180 U/l***), accompanied by a significant increase of hepatic bile production (1.28 +/- .32 vs 0.80 +/- 0.16 microliter/g/min*) and tissue levels of ATP (6.12 +/- 1.73 vs 4.21 +/- 1.30 mumol/g*). Laser Doppler flowmetry revealed a significant improvement by BN52021 of left lobular erythrocyte flux recovery from 27 +/- 25 to 78 +/- 19% of respective preischemic control values. The data give evidence for an implication of PAF in I/R damage to the vascular endothelium and in impaired parenchymal function of the liver, probably due to altered microvascular reperfusion. Treatment with PAF antagonists should improve results after liver surgery under ischemic conditions. (*;**;***: P < 0.05; 0.01; 0.001).
...
PMID:Involvement of platelet activating factor in microcirculatory disturbances after global hepatic ischemia. 774 67
Ergot alkaloids possess some properties potentially beneficial in
ischemia
of organs. Therefore the effect of pretreatment by nicergoline and bromocriptine was established in
ischemia
-reperfusion injury of rat liver. PGE2 and verapamil were used as comparative agents. Hepatic
ischemia
(60 min) of anesthetized rats was induced by clamping of vessels supplying the median and left lateral lobe. Tested drugs were given i.v. 2 or 5 min prior to inducing
ischemia
.
ALT
and AST activities in serum two hours after the end of
ischemia
were used as markers of hepatocellular injury. Only PGE2 (0.1 mg.kg-1) pretreatment minimized the postischemic rise of both
ALT
and AST activities. Pretreatment with various doses of nicergoline (1 or 4 mg.kg-1), bromocriptine (1 or 4 mg.kg-1) and verapamil (0.9 or 4.5 mg.kg-1) did not influence significantly serum transaminases activities after
ischemia
. Bromocriptine (4 mg.kg-1) given together with PGE2 did not improve a protective effect against
ischemia
achieved by the administration of PGE2 (0.1 microgram.kg-1).
...
PMID:The effect of pretreatment with prostaglandin E2 (PGE2), verapamil, nicergoline and bromocriptine on ischemia-reperfusion injury of rat liver in vivo. 776 87
Aiming at investigating biochemical markers of Primary Graft Nonfunction (PNF) in Orthotopic Liver Transplantation (OLT) an experimental work is made on 21 Large-White pigs randomly distributed in three groups of seven, and two additional groups of seven donors each. In Group I the supra and infrahepatic cava, the portal vein and the hepatic artery were clamped. After 30 minutes the caval and portal clamps were released and 30 minutes later the arterial clamp was also removed. In Group II (viable), OLT was performed. The Collins solution was used as preservation fluid, keeping the cold
ischemia
time under 2 hours. In Group III (Non-Viable), an OLT was carried out 24 hours of cold
ischemia
with Collins solution. Blood samples are taken in 8 different moments along the procedure to determinate the values of AST,
ALT
, LDH, FA, Bilirubin, Uric Acid, Cholesterol, Triglycerides, Urea, Creatinine, Glucose, Total Protein, Calcium, Phosphorus, CPK and Aldolase. The last 5 samples were drawn after reperfusion. In the Group III we found, in the samples drawn after reperfusion of the graft, significant increases in 5 of these parameters, AST,
ALT
LDH, Aldolase and Uric Acid. We consider that these 5 parameters may be of value in the early diagnosis of PNF of the graft, being the AST and
ALT
the most reliable, with the higher specificity for the same sensitivity.
...
PMID:[Biochemical indicators of primary graft dysfunction in experimental orthotopic liver transplantation]. 776 81
Previously, pentoxifylline treatment of graft recipients was shown to protect against liver graft failure from storage/reperfusion injury after orthotopic rat liver transplantation. To determine whether pentoxifylline also protects against normothermic
ischemia
/reperfusion injury to liver, we induced lobar
ischemia
in rats followed by reflow and partial hepatectomy of the noninvolved liver. In rats receiving pentoxifylline 2 hr before surgery and then twice daily for 5 days, the 1-week survival rate more than doubled from 25% to 67% (P < 0.05). Liver enzymes (
alanine transaminase
, aspartate transaminase, and lactate dehydrogenase) in the serum and liver necrosis evaluated histologically were also significantly reduced in the pentoxifylline-treated rats (P < 0.01). Hepatic
ischemia
/reperfusion increased leukocyte infiltration into the lungs, and pentoxifylline tended to reduce this lung injury (P = 0.06). These results show that pentoxifylline treatment reduces hepatic injury and improves survival after normothermic
ischemia
and reperfusion.
...
PMID:Protection by pentoxifylline against normothermic liver ischemia/reperfusion in rats. 777 68
Hepatectomy was performed under in situ right lobar hypothermic perfusion combined with hepatoprotective agents in six patients who had hepatocellular carcinoma and coexisting liver disease. Following occlusion of the right hepatic vein and the right portal pedicle, in situ cold perfusion was initiated using chilled Ringer's lactate infused through a cannula placed in the right main portal vein. The right superior segments were resected in a bloodless field. The liver was cooled to 22-26 degrees C for 40 to 80 minutes with no significant changes in systemic hemodynamics or body temperature. Postoperative liver functions showed no marked derangement; the mean peak
GPT
was 221 U and the mean peak total bilirubin 2.3 mg d/l. Local cooling minimizes the risk of
ischemia
/reperfusion injury in this very vulnerable population, yet gives the surgeon adequate time to perform a challenging resection in a bloodless field.
...
PMID:Hepatic resection under in situ hemihepatic hypothermic perfusion with hepatoprotective agents. 778 26
The potential beneficial effect of hepatocellular glutathione against inflammatory liver damage was investigated in a model of endotoxin-enhanced
ischemia
-reperfusion injury. Animals were subjected to 20 min of hepatic
ischemia
, followed by 4 hr of reperfusion. The injection of 0.5 mg/kg Salmonella enteritidis endotoxin potentiated liver injury and the postischemic oxidant stress, as indicated by increased plasma levels of glutathione disulfide. Depletion of hepatic glutathione levels by > 90% with phorone and inhibition of glutathione synthesis with buthionine sulfoximine further increased liver injury in this model, as indicated by enhancement of plasma
alanine aminotransferase
activities from 2,234 +/- 122 U/L to 4,024 +/- 282 U/L. Continuous infusion of a glutathione (GSH) solution in GSH-depleted animals (22 mumol/kg/hr) attenuated reperfusion injury by 55%. In vitro experiments demonstrated the capability of GSH to react rapidly with reactive oxygen species, such as hydrogen peroxide (H2O2) and hypochlorous acid (HOCl). Only H2O2 oxidized GSH quantitatively to its disulfide; HOCl oxidized GSH to higher oxidation states. These data support the hypothesis that the enhanced release of hepatocellular GSH functions as a defense mechanism against reactive oxygen species generated by inflammatory cells during endotoxemia and reperfusion. This internal defense system of the liver may be of general importance in preventing, or at least limiting, liver damage by reactive oxygen generated in particular by Kupffer cells during their physiological function to remove gut-derived endotoxin and bacteria.
...
PMID:Beneficial effects of extracellular glutathione against endotoxin-induced liver injury during ischemia and reperfusion. 783 22
We have investigated the effect of two doses of allopurinol (ALL) (100 and 50 mg/kg) administered i.v. on liver function after 1 h of normothermic
ischemia
. ALL given in a concentration of 100 mg/kg significantly improved bile output after 1 and 24 h of reperfusion. Hepatocyte injury reflected by
alanine aminotransferase
(
ALT
) and lactic dehydrogenase (LDH) in plasma was also significantly reduced at 24 h, but not at 1 h of reperfusion compared with controls. ALL administered at a concentration of 50 mg/kg had some protective effect. Significant correlation between circulating liver enzymes and bile output at 24 h after reperfusion indicates an important pathophysiologic link between hepatocyte function and injury in this time window.
...
PMID:Allopurinol dose is important for attenuation of liver dysfunction after normothermic ischemia: correlation between bile flow and liver enzymes in circulation. 785 48
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