Increase In Serum Enzymes Research Articles

The effect of dietary Crataegus Sinaica on the growth performance, immune responses, hemato-biochemical and oxidative stress indices, tissues architecture, and resistance to Aeromonas sobria infection of acrylamide-exposed Clarias gariepinus

This study investigated the effect of using a natural dietary supplement of Crataegus Sinaica (CS) to mitigate the negative impacts of waterborne acrylamide (ACR) on the health and performance of freshwater fish, African catfish (Clarias gariepinus). For this aim, 270 fish were divided into six groups (45 fish/group). Three groups were kept in non-contaminated water and fed a non-fortified basal diet, 1% CS, and 2% CS. The other three groups were exposed to ACR (26.6 mg/L water) and fed a basal diet, 1% CS, and 2% CS. After 60 days, the growth performance, liver and kidney function, stress indicators, oxidative stress indices, immunological response, vital tissue architecture, and resistance to Aeromonas sobria have been evaluated. Results indicated that CS dietary supplementation (1% and 2% CS) significantly counteracted ACR-induced reduced growth and survival. Furthermore, both CS dietary supplementation significantly balanced the ACR-induced leukopenia, anemia, hypoalbuminemia, hypoglobulinemia, and hypoproteinemia. Likewise, 1% and 2% CS addition to the ACR-exposed fish diets significantly reduced the ACR-induced increase in serum enzymes, bilirubin, renal damage products, hyperglycemia, and cortisol. Instead, the ACR-evoked depletion of antioxidant (glutathione peroxidase, superoxide dismutase, catalase, and reduced glutathione) and innate immune (lysozyme, complement3, and nitric oxide) components were significantly restored by both CS dietary supplementation. Besides, the ACR-induced pathological alterations in hepatic, renal, and splenic tissues were considerably lessened by CS. Besides, the reduced disease resistance of ACR-exposed fish was restored when challenged with A.sobria in a fish-fed 1% and 2% CS-fortified diet. Noteworthy, the inclusion of 2% CS produced better results than 1%. Overall, feeding C. gariepinus a diet supplemented with 2% CS significantly improved the fish's overall health, growth, and disease resistance, despite the ACR water pollution that consequently would sustain aquaculture.

Protective Effect of Selenium against Methotrexate Induced Hepatotoxicity

Introduction: The liver is the largest internal organ by percent weight in the human body and has crucial functions, including cholesterol production, intermediary metabolism, hormone synthesis, bile and urea production and drug detoxification. Objectives: The main objective of the study is to analyse the Protective effect of selenium against methotrexate induced hepatotoxicity in mice. Material and methods: This descriptive study was conducted in Jinnah Hospital Lahore during 2020. Selenium and all chemical reagents of analytical grades were purchased from Sigma Chemical Co. (St. Louis, Mo, USA). The dose of MTX diluted in water (50% 1ml/kg of body weight of Mice were applied twice a week for six weeks to induced hepatocellular injury determined by liver function tests. The mice were maintained under pathogen-free conditions with air conditioning, a 12-hr light/12-hr dark cycle, and %55 humidity. Results: Results shows that a significant increase in serum enzymes (ALT, AST, ALP) and significant decrease in total protein was observed in all groups receiving MTX for the induction of hepatic injury. Mice receiving combination therapy of selenium along with MTX shows a time course recovery towards normalcy. The highest value of ALT (94.83 IU/L), AST (73.21 IU/L) and ALP (157 IU/L) were recorded in Mice receiving MTX for hepatic injury. The lowest values (63.67, 51.49 and 139.95 IU/L) was recorded in group treated with MTX+ Se (200mg/kg b.w) but both the groups differed non significantly and shows the same trend but a decreasing trend in serum enzymes (ALT 32.85%), (AST 29.67%) and (ALP 11.40%). Conclusion: It is concluded that selenium supplementation in MTX treated rats elicited a reduction in the toxic effects of the pesticide by improving the studied parameters, which was confirmed by the biochemical analysis of serum.

Hepatoprotective and antioxidant effects of alcesefoliside from Astragalus monspessulanus

The hepatoprotective potential of alcesefoliside (AF) from Astragalus monspessulanus was investigated. Iron sulphate/ascorbic acid (Fe2+/AA) lipid peroxidation was induced in rat liver microsomes and pre-incubated with AF and silybin (100, 10 and 1 µmol). Pronounced effects were observed in 100 µmol. In vivo experiments were carried out on rats, challenged orally with carbon tetrachloride (CCl4) alone and after pre-treatment and followed by curative treatment with AF (10 mg/kg). The activity of the serum and antioxidant enzymes, together with reduced glutathione (GSH) levels and malonedialdehyde (MDA) quantity were measured. Microsomal incubation with Fe2+/AA increased MDA production. The pre-incubation with AF reduced the formation of MDA, comparable to silybin. These findings were supported by the in vivo study where CCl4-induced liver damage was discerned by significant increase in serum enzymes and in MDA production as well as by GSH depletion and reduced antioxidant enzymes activity. The AF pre-treatment and consecutive curative treatment normalizes the activity of the serum and antioxidant enzymes alike, as well as the levels of GSH and MDA. Histological examination of AF-treated livers showed a decrease in the abnormal accumulation of lipids in hepatocytes as well as reduced alterative changes in their structure in a model of CCl4-induced toxicity.

Amelioration of adriamycin-induced cardiotoxicity by Salsola kali aqueous extract is mediated by lowering oxidative stress

ObjectivesTo assess the cardioprotective effect of the Salsola kali aqueous extract against adriamycin (ADR)-induced cardiotoxicity in male Swiss albino mice.MethodsThe aqueous extract of S. kali was phytochemically screened by traditional methods for different classes and further evaluated for antioxidant activity in vitro. In vivo, cardioprotective evaluation of the extract was designed to have four groups of mice: (1) control group (distilled water, orally; normal saline, intraperitoneally (i.p.)); (2) ADR group (15 mg/kg, i.p.); (3) aqueous S. kali extract (200 mg/kg, orally); and (4) ADR + S. kali group. ADR (5 mg/kg) was injected three times over 2 weeks while S. kali was orally administered daily for 3 weeks (1 week before and 2 weeks during ADR treatment). Cardioprotective properties were assessed using biochemical and histopathological approaches.ResultsADR caused a significant increase in serum enzymes (lactate dehydrogenase, creatine phosphokinase, aspartate aminotransferase, and alanine aminotransferase). Myocardial levels of malondialdehyde, nitric oxide, and reduced glutathione, as well as the activities of superoxide dismutase and catalase increased while the activities of glutathione peroxidase and glutathione S-transferase declined. Histopathological examination of heart sections revealed that ADR caused myofibrils loss, necrosis and cytoplasmic vacuolization.DiscussionPretreatment with S. kali aqueous extract normalized serum and antioxidant enzymes minimized lipid peroxidation and cardiac damage. These results have suggested that the extract has antioxidant activity, indicating that the mechanism of cardioprotection during ADR treatment is mediated by lowering oxidative stress.

Chronic Alcohol Consumption Affects Serum Enzymes Levels in the HIV-Infected Patients on Stavudine (d4T)/Lamivudine (3TC)/Nevirapine (NVP) Treatment Regimen

Chronic alcohol use is a common problem globally among the HIV-infected patients on ARV treatment regimens, leading to severe liver damage and increase in serum enzymes. The study determined effect of chronic alcohol intake on serum enzymes (alanine aminotransferase (ALT), aspartate aminotransferase (AST) and γ-glutamyl transferase (GGT)) in HIV-infected patients on d4T/3TC/NVP treatment regimen in Uganda using the WHO alcohol use disorders’ identification test (AUDIT) tool and chronic alcohol use biomarkers (ALT, AST, GGT, AST/ALT ≥ 2.0 and mean corpuscular volume (MCV)). A case control study using repeated measure design with serial measurements model was used. Alcohol use biomarkers were used to standardize the gender differences in alcohol use. A total of 41 patients (21 alcohol group and 20 control group) were followed up for 9 months with blood sampling done at 3 month intervals. The serum enzymes’ levels were determined by using the Cobas Intergra 400 Plus analyzer system. The mean GGT levels were higher in chronic alcohol use group as compared to control group in both groups. The levels were above reference ranges during 6 month and three times higher during 9-month follow-up period for both chronic alcohol use self reporting WHO AUDIT tool and biomarkers’ groups. Generally, the mean AST, ALT and AST/ALT levels were slightly higher in alcohol use group as compared to control group and were slightly higher in both groups as compared to reference ranges during the 9 month follow-up period. Chronic alcohol consumption by HIV-infected patients on d4T/3TC/NVP drug regimen increased GGT and AST/ALT serum enzyme levels and hence was used as chronic alcohol use biomarkers.

Inhibitory effect of Nymphaea pubescens Willd. flower extract on carrageenan-induced inflammation and CCl4-induced hepatotoxicity in rats

Nymphaea pubescens Willd. is used as ingredient of ethnic diet and folk medicine in South-East Asia. The water (NPW), methanol (NPM) and chloroform (NPC) extracts of N. pubescens flowers were investigated for NO·, O₂·⁻ and DPPH radical scavenging and iron chelating activities in vitro. NPW was found to be the most potent free radical scavenger (EC₅₀<100 μg/mL) whereas NPC did not show EC₅₀ at 500 μg/mL. Therefore, NPW was selected for further studies on anti-inflammatory and hepatoprotective activities, using standard in vitro and in vivo models. NPW exhibited inhibition of nitrogen radical generation in LPS-activated macrophages (IC₅₀=75.5 μg/mL) through suppression of iNOS protein, with no associated toxicity in the cells. Further, 500 mg/kg of NPW reduced rat paw edema by ~50% after 6h of carrageenan administration. Hepatoprotective activity of NPW was also evaluated in vivo on CCl4-induced hepatotoxicity model in rats. NPW treatment (500 mg/kg/day for ten days) attenuated CCl4-induced increase in serum enzymes, viz. alanine and aspartate aminotransferases (ALT and AST) and bilirubin. Also, glutathione and superoxide dismutase (SOD)-levels were restored towards normalcy in the liver of CCl4-treated rats, indicating the hepatoprotective role of NPW, which was found to contain a fair amount of flavonoids, phenolics, and saponin constituents.

Protective effects of coumarin and coumarin derivatives against carbon tetrachloride-induced acute hepatotoxicity in rats

The comparison of the antioxidant activity of some coumarins with their molecular structure is well determined. However, the protective function of coumarins with various chemical structures against liver toxicity has not yet been well established. Therefore, the aim of this study was to evaluate the possible cytoprotective properties of coumarin and some coumarin derivatives against CCl 4 (carbon tetrachloride)-induced hepatotoxicity. Coumarin (1,2-benzopyrone) and coumarin derivatives esculetin (6,7-dihydroxycoumarin), scoparone (6,7-dimethoxycoumarin) and 4-methylumbelliferone (7-hyroxy-4-methyl) were examined for their protective effect against CCl 4-induced hepatotoxicity in Male Sprague-Dawley rats. A single toxic dose of CCl 4 (1.25 ml kg −1, orally) produced liver damage in rats, seen histologically as centrilobular necrosis. Administration of CCl 4 increased serum enzyme levels of aspartate transaminase (AST), alanine transaminase (ALT), and alkaline phosphatase (ALP). Pre-treatment of rats with esculetin (31.15 mg kg −1, orally) and scoparone (35 mg kg −1, orally) significantly prevented CCl 4-induced increase in serum enzymes, whereas 4-methylumbelliferone (35 mg kg −1) and coumarin (30 mg kg −1) had no effect against CCl 4-induced rise in serum enzymes. Morphological findings were consistent with the plasma transaminase observations. Among the coumarin analogs, esculetin, which possesses orthodihydroxy coumarins, showed the strongest protective effect against CCl 4-induced liver damage, followed by scoparone, 4-methylumbelliferone and coumarin, respectively. The results of this study indicate that the chemical structures of coumarins play an important role in the prevention of liver toxicity.

Pseudomonas aeruginosa Exotoxin A-Induced Hepatotoxicity: An Animal Model in Rats

Pseudomonas aeruginosa exotoxin A (PEA) has been generally used to induce liver injury in mice for experimental study. No PEA-induced hepatotoxicity study has ever been conducted in rats, although rats are the most common rodents used in toxicologic bioassay and pharmacological evaluation. The present study was conducted in male Wistar rats that were injected (i.v.) with PEA at doses of 0, 10, 20, 30 or 40 microg/kg body weight and evaluated at 12, 24, 36, 48 and 60 hr post-exposure (HPE). Rats exposed to PEA at 40 microg/kg died before 36 HPE, and the mortality was dose and time dependent. Liver injury was noted as increases in serum enzymes, along with alterations of liver histology in the 40 microg/kg group at 12 HPE. TUNEL-positive staining indicative of hepatocyte apoptosis was observed in the 20 microg/kg group at 12 HPE. Significant levels of DNA fragmentation ladder were observed in the 30 microg/kg group starting at 24 HPE. Serum levels of TNF-alpha was increased in the 30 and 40 microg/kg groups at 48 and 24 HPE, respectively. Other cytokines, such as IL-2, IL-6, and IL-10 were also increased at various doses and times. Furthermore, the elevated serum hepatic index levels decreased significantly by dexamethasone pretreatment. In contrast, these markers were exacerbated by co-administration of a non-toxic dose LPS. In overall evaluation, the PEA-induced liver injury can be used as a model for study of hyperimmune-mediated hepatotoxicity.

El flujo como indicador del efecto terapéutico del ácido folínico en la isquemia-reperfusión

An intestinal reperfusion study with two aims: a) to assess the usefulness of intestinal capillary blood flow measurement by laser-Doppler for intestinal reperfusion studies; and b) to compare the effects of racemic and levo forms of folinic acid in treating the syndrome. A murine model of intestinal ischemia by completely clamping the superior mesenteric artery for 90 minutes. A comparison was made of three treatment groups: saline, folinic acid, and levo-folinic acid. The following factors were analyzed: changes in biochemical parameters (levels of creatine kinase, lactic dehydrogenase, and alkaline phosphatase at 60 minutes, and at two and seven days after restoring blood flow), capillary flow in the jejunum and ileum by laser-Doppler (during ischemia and after the first hour of reperfusion), intestinal mucosa injury, and survival curve. Laser-Doppler provided reliable data on how the different treatments affected capillary flow during intestinal reperfusion. Levo-folinic acid improved capillary flow in the ileum after 25 minutes of reperfusion, and also reduced mucosal injury in the same stretch of intestine by the seventh day post-reperfusion (p<0.05). On the other hand, it produced an initial increase in serum enzymes during reperfusion, and did not modify survival. The changes observed in intestinal capillary blood flow measurement by laser-Doppler have similarities with the effects of drugs on pathological mucosal changes. We could not prove that the levo form of folinic acid has a stronger protective effect versus racemic folinic acid in intestinal ischemia-reperfusion syndrome.

Pirfenidone prevents endotoxin-induced liver injury after partial hepatectomy in rats

Background/Aims: Massive liver resection causes a variety of complications including endotoxemia. Pirfenidone (PFD) is a new experimental drug used as antifibrotic agent. Studies were performed to investigate whether PFD influences the survival rate of animals with endotoxin-induced liver injury after partial hepatectomy, and the mechanisms involved. Methods: Rats were treated with lipopolysaccharide (LPS) 48 h after 70% hepatectomy. PFD was administered orally before LPS injection. Results: PFD improved the survival rate of LPS-treated rats after hepatectomy. PFD prevented increases in serum enzymes and total bilirubin related to liver injury. Histopathological analysis revealed that PFD inhibited the enhancement in hepatic necrosis and apoptosis. Further, PFD inhibited increases of inflammatory cytokines and cytokine-induced neutrophil chemoattractant (CINC) in serum and liver, followed by decreases of number of infiltrating neutrophils into liver. Electrophoretic mobility shift assay revealed that PFD inhibited the activation of transcription factor nuclear factor-κB (NF-κB) induced by LPS. PFD also reduced the induction of inducible nitric oxide synthase (iNOS) in the liver of LPS-treated rats. Conclusions: These results indicate that PFD inhibits the productions of inflammatory cytokines, CINC and iNOS in part through the inhibition of NF-κB activation, resulting in the prevention of endotoxin-induced liver injury after hepatectomy.

Acute, short-term, and subchronic oral toxicity of 1,1,1-trichloroethane in rats.

1,1,1-Trichloroethane (TRI) is a widely used solvent that has become a frequent contaminant of drinking water supplies in the U.S. There is very little information available on the potential for oral TRI to damage the liver or to alter its P450 metabolic capacity. Thus, a major objective of this investigation was to assess the acute, short-term, and subchronic hepatotoxicity of oral TRI. In the acute study, male Sprague-Dawley (S-D) rats were gavaged with 0, 0.5, 1, 2, or 4 g TRI/kg bw and killed 24 h later. No acute effects were apparent other than CNS depression. Other male S-D rats received 0, 0.5, 5, or 10 g TRI/kg po once daily for 5 consecutive days, rested for 2 days, and were dosed for 4 additional days. Groups of the animals were sacrificed for evaluation of hepatotoxicity 1, 5, and 12 days after initiation of the short-term experiment. This dosage regimen caused numerous fatalities at 5 and 10 g/kg, but no increases in serum enzymes or histopathological changes in the liver. For the subchronic study, male S-D rats were gavaged 5 times weekly with 0, 0.5, 2.5, or 5.0 g TRI/kg for 50 days. The 0 and 0.5 g/kg groups were dosed for 13 weeks. A substantial number of rats receiving 2.5 and 5.0 g/kg died, apparently due to effects of repeated, protracted CNS depression. There was evidence of slight hepatocytotoxicity at 10 g/kg, but no progression of injury nor appearance of adverse effects were seen during acute or short-term exposure. Ingestion of 0.5 g/kg over 13 weeks did not cause apparent CNS depression, body or organ weight changes, clinical chemistry abnormalities, histopathological changes in the liver, or fatalities. Additional experiments did reveal that 0.5 g/kg and higher doses induced hepatic microsomal cytochrome P450IIE1 (CYP2E1) in a dose- and time-dependent manner. Induction of CYP2E1 activity occurred sooner, but was of shorter duration than CYP2B1/2 induction. CYP1A1 activity was not enhanced. In summary, 0.5 g/kg po was the acute, short-term, and subchronic NOAEL for TRI, for effects other than transient CYP2E1 induction, under the conditions of this investigation. Oral TRI appears to have very limited capacity to induce P450s or to cause liver injury in male S-D rats, even when administered repeatedly by gavage in near-lethal or lethal dosages under conditions intended to maximize hepatic effects.

Contribution of Direct Solvent Injury to the Dose-Dependent Kinetics of Trichloroethylene: Portal Vein Administration to Rats

Presystemic elimination of trichloroethylene (TCE), a common contaminant of drinking water, has been shown by Lee et al. (Toxicol. Appl. Pharmacol. 139, 262–271, 1996) to be inversely related to dose. When relatively high doses were administered to rats via the portal vein (PV), first-pass hepatic extraction became negligible. This phenomenon could result not only from metabolic saturation, but from suicidal destruction of cytochromes P450 and hepatocellular injury as well. The objectives of the current investigation were to: (a) clarify the relative roles of P450 depletion and hepatocellular toxicity in the apparent cessation of hepatic elimination of TCE in animals given relatively high doses of TCE via the PV; and (b) investigate mechanism(s) of hepatocellular injury under such exposure conditions. TCE (16 and 64 mg/kg body weight (bw) was incorporated into a 5% aqueous Alkamuls emulsion and injected via an indwelling jugular vein (JV) or PV cannula into male Sprague–Dawley rats. Some animals received 73.5 μmol/kg of p-nitrophenol (PNP), a competitive metabolic inhibitor of TCE, through the PV cannula 3 min before TCE. Administration of TCE via the PV resulted in deposition of relatively high levels of TCE in the liver. PV dosing resulted in lower total hepatic P450 levels than did JV dosing. PV dosing produced marked elevations of cytoplasmic enzymes in serum, but JV dosing did not. Decreases in hepatic P450 were not selective for cytochrome P4502E1. Histological examination of the liver of PV-dosed rats revealed periportal rather than centrilobular necrosis. PNP pretreatment failed to prevent the increase in serum enzymes, decrease in hepatic P450 content, and hepatic necrosis following PV TCE. It is concluded that PV injection of bolus doses of TCE ≥ 16 mg/kg causes liver injury within minutes in rats, primarily through direct solvent action on hepatocellular membranes rather than by P450-mediated effects. This liver damage likely plays a modest role in reducing the liver's capacity to metabolize high PV doses of TCE.

Rise in plasma oxidized glutathione by experimental hypoglycemia.

Changes in plasma glutathione were investigated under hypoglycemic status. Twelve rabbits were randomly divided into hypoglycemic group (n=6) and saline-injected control group (n=6). Hypoglycemia was induced by intravenous injection of insulin as 10 U/kg and recovered by intravenous glucose injection after 60 minutes. In the control group, saline was intravenously injected in stead of insulin. Plasma levels of oxidized glutathione (GSSG) rose significantly (p<0.01) and remarkably decrease in plasma GSH/GSSG ratio (p<0.05) accompanying increase in serum enzymes in the hypoglycemic group. These results suggest that hypoglycemia might cause change in plasma GSSG which is related to increase of serum enzymes by hypoglycemia.

Prevention of acetaminophen-induced hepatotoxicity by ternatin, a bioflavonoid fromEgletes viscosa less

The hepatoprotective effect of ternatin, a tetramethoxyflavone from Egletes viscosa L. was investigated in mice against acetaminophen-induced hepatic damage and lethality. Hepatotoxicity was assessed by quantifying serum activities of alanine aminotransferase (ALT), aspartate aminotransferase (AST), lactic dehydrogenase (LD) and malondialdehyde (MDA) concentration in liver homogenates as well as by histopathological examination of liver tissue. Acetaminophen (300 mg/kg) produced liver damage in mice as manifested by a 29-, 23- and 7-fold rise in serum levels of ALT, AST and LD, respectively, compared with controls. Ternatin (25 and 50 mg/kg) was able to prevent significantly (p < 0.05) acetaminophen-induced acute increase in serum enzymes. In addition, the severity of histological alterations induced by acetaminophen as evidenced by centrilobular necrosis and cellular infiltration were greatly diminished in animals that received ternatin. The data suggest a hepatoprotective activity of ternatin in mice against toxicity induced by acetaminophen. Copyright © 1998 John Wiley & Sons, Ltd.

Disruption of sphingolipid metabolism and induction of equine leukoencephalomalacia by Fusarium proliferatum culture material containing fumonisin B 2 or B 3

Fumonisin B 1, B 2, and B 3 are inhibitors of ceramide synthase, a key enzyme in the pathway for de novo sphingolipid biosynthesis. Corn, naturally contaminated with either predominantly fumonisin B 1 or pure fumonisin B 1, has been shown to cause equine leukoencephalomalacia (ELEM). It has been hypothesized that fumonisin-induced disruption of sphingolipid metabolism is an early event in the development of ELEM. Recently, it was shown that Fusarium proliferatum corn culture diets containing predominantly fumonisin B 2, but not diets which were predominantly fumonisin B 3, at 75 ppm (0.75 mg/kg BW/day) caused hepatotoxicity and ELEM. Analysis of free sphingoid bases and complex sphingolipids in serum, liver, and kidney, revealed that both the fumonisin B 2 and B 3 diets caused significant disruption of sphingolipid metabolism, however, the fumonisin B 2 culture material diet was significantly more effective than the fumonisin B 3 culture material diet at disrupting sphingolipid metabolism and in causing hepatotoxicity and clinical signs indicative of the onset of ELEM. A significant increase in the ratio of free sphinganine to free sphingosine in serum was first evident at day 4 and 11 with the fumonisin B 2 and B 3 diets, respectively. Increase in serum enzymes indicative of liver toxicity was first evident at day 34 in ponies fed the fumonisin B 2 diet and clinical signs (head shaking, gait problems, and muscle tremors) were first observed at day 48. Ponies fed the fumonisin B 3 diets showed no increase in serum enzymes or clinical signs for as long as 65 days when the study with fumonisin B 3 was stopped. The results support the conclusion fumonisin B 2 is more effective than fumonisin B 3 in disrupting sphingolipid metabolism and induction of ELEM and liver injury in ponies.

Sex Differences in Rat Hepatic Cytolethality of the Protein Kinase C Inhibitor Safingol: Role of Biotransformation

Safingol [(2S,3S)-2-amino-1,3-octadecanediol], a sphingosine analog that inhibits protein kinase C, was developed to treat dermatoses and cancer. Preclinical toxicology studies performed to assess the effects of safingol showed that 6 weeks of dermal application over 10% of body surface area caused dose-dependent increases in serum enzymes and hepatic histopathological changes associated with liver damage in female rats. Liver toxicity was not seen in male rats at the same doses. Plasma safingol concentrations were similar in male and female rats following topical exposure. The underlying mechanism(s) for the sex differences in toxicity in rats were examined using isolated hepatocytes. Anin vitromodel of male versus female differences in safingol·HCl-induced hepatotoxicity was established using a suspension/culture technique. Concentrations of safingol·HCl which produced cytolethality in 50% of the hepatocytes were 125 and 48 μMfor male and female rat hepatocytes, respectively. Cytolethality was time-, concentration-, and cell number-dependent. Inhibition of cytochrome P450in vitrowith 1-phenylimidazole increased safingol·HCl-induced cytolethality in male but not female hepatocytes, suggesting that male rat hepatocytes have a cytochrome P450 isoenzyme which metabolizes safingol·HCl to an inactive metabolite thus reducing hepatotoxicity. Furthermore,in vivopretreatment with the CYP4A-inducing agent, clofibrate, protected both male and female hepatocytes from cytolethality. The results of this study indicate that the sex differences seen in hepatotoxicity could be due to differences in biotransformation such that female rat hepatocytes either lack or have a reduced constitutive level of a cytochrome P450 isoenzyme that metabolizes safingol to a nontoxic metabolite. In addition, safingol [bnproduced hepatocyte cell death without inflammationin vivo,and a “ladder-like” DNA fragmentation patternin vitro,consistent with an apoptotic mechanism of cell death.

ARTERIAL KETONE BODY RATIO AND GLUCOSE ADMINISTRATION AS AN ENERGY SUBSTRATE IN RELATION TO CHANGES IN KETONE BODY CONCENTRATION AFTER LIVING-RELATED LIVER TRANSPLANTATION IN CHILDREN

Changes in the arterial ketone body ratio (AKBR [acetoacetate/3-hydroxybutyrate]), which reflect the redox state of the liver mitochondria (NAD+/NADH), as well as those in total ketone body concentration (TKB) and blood glucose level were studied in 30 living-related liver transplantations (LRLT) performed in pediatric patients at Kyoto University Hospital from June 1990 to January 1992. AKBR increased to over 1.0 within 6 hr after reperfusion of the graft in 11 cases (37%), within 12 hr in 7 (23%), on POD 1 in 8 (27%), and on POD 2 in the remaining 4 cases (13%). TKB significantly increased while AKBR remained below 0.7 (266 +/- 40 mumol/L), but it significantly decreased in accordance with the recovery of AKBR above 1.0 (61 +/- 6 mumol/L). This indicates the change in the predominant energy substrate for hepatic mitochondria from fatty acid to glucose during the AKBR recovery process. In 6 cases, the AKBR transiently decreased to below 1.0 after initial recovery concomitant with the fall in blood glucose level and the increase in TKB. However, the AKBR was rapidly restored to over 1.0 again immediately after the glucose administration was increased. This suggests that glucose administration to maintain blood glucose level between 150 and 250 mg/dl is essential for the AKBR recovery above 1.0 that accompanies the normalization of graft metabolic functions, and that, along with the postoperative minimal increase in serum enzymes and favorable outcome of the transplant with no incidence of a primary nonfunctioning graft, the prompt and successful recovery of AKBR reflects the expected high viability of the graft in our LRLT cases.

Strenuous exercise simulating hepatic injury during vaccine trials

Three healthy young men participating in phase 1 clinical vaccine trials had unexplained increases in their serum transaminase levels. Retrospective analysis indicated that these volunteers had participated in strenuous physical training 2–5 days prior to the noted elevations. The pattern of serum enzyme elevations, initially thought to be consistent with hepatic injury, were associated with parallel increases in creatine phosphokinase. One individual consented to repeat his exercise regimen. This was followed by a recurrence of the same pattern of increases in serum enzymes, including creatine phosphokinase. Thus, in trials where serum enzymes will be measured, it may be prudent to encourage subjects to refrain from increasing their activity above that which they normally perform.

Serum enzyme changes in newborn calves fed colostrum.

In 10 newborn Holstein calves, which were initially bottle-fed on pooled colostrum, there were transient increases in several serum enzymes. Within a few hours, the mean serum gamma-glutamyl transferase (gammaGT), aspartate aminotransferase (AST), alkaline phosphatase (ALP), acid phosphatase (ACP), and lactate dehydrogenase (LDH) activities increased 62.5, 2.4, 2.0, 1.8 and 1.3 fold, respectively. In two other calves given initial feeds of enzyme-free pasteurized milk, there were similar increases in serum enzymes, except serum gammaGT. Correct interpretation of serum enzyme activities in newborn calves must take into account the normal increases which occur after feeding colostrum. Serum gammaGT was the only enzyme to increase markedly as a result of its absorption from colostrum. The other serum enzymes are presumably released from the tissues of the calf. The increased activities of serum CK observed in some newborn calves probably resulted from trauma during birth or increased muscular activity after birth.

Serum and cerebrospinal fluid enzymes in subarachnoid haemorrhage

Serum levels of creatine kinase (CK) and its isoenzyme CK-MB, lactate dehydrogenase (LDH), hydroxybutyric dehydrogenase (HBDH), glutamic oxalacetic transaminase (GOT) and glutamic pyruvic transaminase (GPT) were studied in 50 patients with subarachnoid haemorrhage. In 18 cases the cerebrospinal fluid (CSF) was also examined for total concentration of CK and CK-MB. The results were correlated with the degree of neurological deterioration, the angiographic spasm and prognosis. Concurrent increase of CK-MB, LDH and HBDH serum levels indicates a poor prognosis, whereas increase of GOT and GPT does not have clinical significance. High CK-MB levels in CSF were associated with the worst clinical evolution. However, increase of serum enzymes coincided in most cases with the appearance of the spasm. Monitoring of CK-MB, LDH and HBDH serum levels can be useful for following the evolution of the spasm and in predicting the outcome for patients with subarachnoid haemorrhage.