LIFE IN ZERO MAGNETIC FIELD. III. EFFECT ON ZINC AND COPPER IN HUMAN BLOOD SERUM DURING IN VITRO AGING

The purpose of the work was to further investigate the effect of zero magnetic field (ZMF) on the concentration of ions in the human blood compared to the effect of the normal geomagnetic field (GMF). We have investigated the total Zn and Cu concentrations in the blood serum during in vitro aging of blood. The investigation was carried out both on blood from healthy donors as well as from chronic bronchial asthma (BA) patients. Blood samples were kept for 48 hours in a Helmholtz coil compensating system to remove the static component of the geomagnetic field, at room temperature. We found that zinc concentrations in the plasma were not significantly influenced by the exposure to ZMF compared to GMF for both healthy and pathological samples. In contrast, copper concentration was found to be significantly sensitive to the magnetic environment. Healthy blood showed a slight loss of copper from the blood serum in GMF, which further increased in ZMF. BA pathology is characterized by four distinct types of disease, which showed both qualitative and quantitative distinctive sensitivity to the magnetic environment, as compared to healthy blood. The aging effect appeared to be slowed down for most of the BA types of pathologies. These results point to the sensitivity of ion binding to serum proteins and/or transport through cell membranes in the magnetic environment, in our case in the absence of the normal geomagnetic field.     

Effects of Buprenorphine on Balance of Oxidant/Antioxidant System in the Different Ages of Male Rat Liver

Our knowledge about a link between buprenorphine and hepatotoxicity is controversial. This study evaluated the effects of buprenorphine on the liver of young, adult, and aged rats. For this reason, young, adult, and aged rats received intraperitoneally 0.25, 0.5, and 1 mg/kg buprenorphine for 30 days. The present results revealed that the normal aging was associated with a significant decrease in the activities of antioxidant enzymes, and an increase in the liver lipid peroxidation, serum aspartate aminotransferase (AST), alanine aminotransferase (ALT), and lactate dehydrogenase (LDH) activities in the aged rats. This study also demonstrated that buprenorphine led to a significant increase in the serum activities of ALT, AST, and LDH as well as liver lipid peroxidation content with a decrease in the antioxidant enzymes in the liver of buprenorphine‐treated aged rat versus the aged matched control animals. In conclusion, the present results demonstrate that buprenorphine deteriorated oxidative damage in the aged livers.     

Effects of Rumex patientia L. extract on some drug-metabolizing enzymes in rat liver

The effect of aqueous extract from the roots of Rumex patientia L. (Polygonaceae) (D-1), a traditional Turkish medicine used as a laxative and cholagogue, on drug-metabolizing enzymes, such as cytochrome P4502E1, NADPH cytochrome c reductase, NADH cytochrome b5 reductase and glutathione-S-transferase (GST); and serum aspartate aminotransferase (AST) and alanine aminotransferase (ALT) were studied in male Wistar albino rat liver. A significant increase was observed in cytochrome P4502E1 and GST activities, but not in NADPH-cytochrome c reductase and NADH-cytochrome b5 reductase activities. Serum AST and ALT activities were found within the normal laboratory range values. The results demonstrated that the aqueous extract of R. patientia triggers induction of cytochrome P4502E1 in liver and cytosolic GST activity.     

Population distribution profiles of the activities of blood alanine and aspartate aminotransferase in the normal F344 inbred rat by age and sex

Data on the blood enzyme activities of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) were collected from control male and female F344 rats participating in toxicity studies at 17, 30, 56, 80 and 106 weeks of age. The data were skewed to the right with significant deviation from normality. Applying the Box-Cox transformation, it was concluded that approximately normal distributions could be obtained by using the reciprocal transformation. In general, the males showed a greater degree of heterogeneity for both enzymes. Enzyme activities at 17 weeks were lowest for both ALT and AST. There was a high correlation between the activities of blood ALT and AST, with some animals showing dramatic transient increases. Significant differences among studies with respect to the enzyme activities in rats of the same age were demonstrated.     

Sequential measurement of aminotransferase activities by amperometric biosensors

An l-glutamate biosensor modified by cation exchanger membrane on a palladium (Pd) electrode was designed for the purpose of preventing interferences and electrode fouling during the measurement of serum AST and ALT activities. The rate of signal increase obtained by our sensor for the determination of AST and ALT activity was 0.259 and 0.596 nA/min U(-1)l and the response of the sensor to AST and ALT activity were linear over the range of 8-200 and 8-250 Ul(-1), respectively. Both AST and ALT activities could be measured sequentially by injecting the serum into a solution containing l-aspartate and alpha-ketoglutarate. The rate of current increase was relative to AST activity. The activity of ALT was sequentially determined after addition of l-alanine into the solution. The change in the current increase rate after the addition of l-alanine was proportional to the ALT activity. By using the proposed biosensor, the interference of 1mM ascorbic acid was negligible on a dynamical aminotransferase determination when the dynamic data are taken after the steady state of an elevated baseline has been reached. The proposed l-glutamate biosensor provides adequate sensitivity for the measurement of AST and ALT and is expectable to be applied for rapid blood screening of AST and ALT activity in clinical sample.     

Serum alanine aminotransferase to aspartate aminotransferase ratio and degree of fatty liver in morbidly obese patients

We evaluated the change in serum alanine aminotransferase (ALT; EC 2.6.1.2) to serum aspartate aminotransferase (AST; EC 2.6.1.; ALT/AST) ratio with the degree of fatty liver in morbidly obese patients. A total of 31 patients were included in the study. Fatty liver was graded as 0 to 4+. The mean and SD of AST and ALT were not significantly different between groups of patients with various grades of fatty liver. There was, however, a significant correlation between the ALT/AST ratio and the degree of fatty infiltration of the liver. This, we believe, implies damage mainly to the plasma membrane allowing loss of cytoplasmic enzymes rather than loss of mitochondrial enzymes.     

Cytoprotective effects of carvedilol against oxygen free radical generation in rat liver

The protective effects of carvedilol, an antihypertensive agent, against oxidative injury caused by acetaminophen were studied in rat liver. Male Wistar rats (250 +/- 30 g) were pre-treated with carvedilol (3.6 mg/kg, p.o.) for 10 days and on the 11th day received an overdose of acetaminophen (800 mg/kg, p.o.). Four hours after acetaminophen administration, blood was collected to determine serum aspartate aminotransferase (AST) and alanine aminotransferase (ALT). After that, rats were killed and the livers were excised to determine reduced glutathione (GSH), thiobarbituric acid reactive substances (TBARS) and carbonyl protein contents, and the activity of the antioxidant enzymes catalase (CAT), superoxide dismutase (SOD), glutathione peroxidase (GPx), and glutathione S-transferase (GST), and also the DNA damage index. Acetaminophen significantly increased the levels of TBARS, the DNA damage and SOD, AST and ALT activities. Carvedilol was able to prevent lipid peroxidation, protein carbonilation and DNA fragmentation caused by acetaminophen. Moreover, this drug prevented increases in SOD, AST and ALT activities. These results show that carvedilol exerts cytoprotective effects against oxidative injury caused by acetaminophen in rat liver. These effects are probably related to the O2*- scavenging property of carvedilol or its metabolites.     

The Influence of Methionine, Selenomethionine, and Vitamin E on Liver Metabolic Pathways and Steatosis in High-Cholesterol Fed Rabbits

Significant disorders of liver metabolic pathways enzymes after high-cholesterol diet could give information on liver steatosis development. This process could probably also be inhibited by some compounds, as examined in rabbits. Forty-two male rabbits were served a high-cholesterol diet (2 g%) (0.67 g/kg b.m./24 h) with addition of d,l-methionine (70 mg/kg b.m./24 h) or seleno-d,l-methionine (12.5 μg/kg b.m./24 h) or α-tocopherol (10 mg/kg b.m./24 h) for 3 months to compare the protection effect of used compounds on liver metabolism and steatosis. At the beginning and every month, blood was taken. After the experiment was completed, livers were dissected for histological examinations. The concentration of total cholesterol (t-CH), triacylglycerol (TG), and the activities of aldolase (ALD), sorbitol dehydrogenase (SDH), glutamate dehydrogenase (GLDH), lactate dehydrogenase (LDH), aspartate aminotransferase (AST), and alanine aminotransferase (ALT) were determined. Plasma t-CH and TG concentrations were significantly higher in all experimental groups vs control group. Blood serum AST and ALT activities did not undergo change but there were observed not significant increase in the CH group vs control group. Activities of SDH, GLDH, and LDH increased in blood serum and decreased in the liver in all experimental groups. Activities of LDH and SDH increased in the liver in the CH+Met group vs CH group. ALD activity decreased in the liver only in the CH and CH+Se groups. This data support a lipotoxic model of cholesterol-mediated hepatic steatosis. Prolonged administration of high-cholesterol diet not only disturbs the structure of cell membranes, which is expressed by decreased activity of enzymes in the liver and the migration of those enzymes to plasma but as well leads to steatosis of the liver, which has been confirmed by histological examinations. The applied compounds appear to have a varying influence upon the activity of enzymes determined in serum and liver. Obtained results showed a beneficial influence of methionine and vitamin E supplementation on liver steatosis development.     

己酮可可碱对非酒精性脂肪性肝炎大鼠肝脏超微结构和酶组织化学的影响

目的研究己酮可可碱(PTX)对非酒精性脂肪性肝炎(NASH)大鼠肝脏超微结构和酶组织化学的影响。方法高脂饮食建立大鼠非酒精性脂肪性肝炎模型。取SD大鼠40只,分为对照组、12w模型组、16w模型组和治疗组,每组10只。腹主动脉采血,测ALT、AST、血糖等水平。取肝组织做电镜和SDH、CCO、ATPase、LDH的酶组织化学染色。结果两个模型组均比对照组ALT、AST、血糖升高,LDL降低(P<0.05)。治疗组血糖、AST比16w模型组降低(P<0.05)。电镜显示16w模型组线粒体肿大,嵴排列紊乱,基质密度降低。治疗组结构改善。酶组织化学显示四种酶的活性16w模型组均较对照组降低(P<0.05),治疗组活性均较16w模型组升高(P<0.05)。结论NASH时存在肝细胞能量代谢障碍,经PTX治疗后能量代谢障碍得到改善。     

Influence of Convulsants on Rat Brain Activities of Alanine Aminotransferase and Aspartate Aminotransferase

There exist differences between 12-day-old and adult rats in the onset of seizures induced by some inhibitors of glutamate decarboxylase (GAD). The aim of study was to investigate if there are differences between both groups in activities of rat brain alanine aminotransferase (ALT) and aspartate aminotransferase (AST), the enzymes involved in glutamate metabolism, after the administration of 3-mercaptopropionic acid as specific GAD inhibitor or isoniazid as less specific general inhibitor of pyridoxal enzymes. Activities of both aminotransferases in a supernatant 20,000 g of the whole brain (containing predominantly cytosolic isoforms of enzymes) were increased at the beginning of 3-mercaptopropionic acid-induced generalized tonic-clonic seizures. At isoniazid-induced generalized tonic-clonic seizures, a significant increase in both enzyme activities was observed in adult rat brain. In the 12-day-old rat brain, ALT and AST activities reached about 40% and about 50–60% of adult control levels, respectively. In in vitro experiments, no influence of 3-mercaptopropionic acid on transaminase activities was found and an inhibitory effect of isoniazid on the enzymes was confirmed. Increased aminotransferase activities might participate in the enhanced synthesis of excitatory amino acid neurotransmitters in the nervous system, which may take a part in the initiation of epileptic seizures. Alternatively, the increased AST activity may be connected with an increased transport of NADH from the cytosol to mitochondria, while the increased ALT activity would represent the transformation of pyruvate to alanine as a consequence of increased glycolysis.     

Heat acclimation causes some alterations in serum enzymes activities in streptozotocin-diabetic rats

The present study investigated the effect of long-term heat acclimation and experimental diabetes on serum activity of transaminases (AST, ALT), ALP, LDH and elastase complex, as well as blood glucose and HbA1c level in Wistar rats. The heat acclimation model was established with the artificial heat chamber (35±1 °C and 30-40% humidity) for a period of 28 days, while the control groups were held on 20±2 °C. Experimental diabetes was induced by single streptozotocine (STZ) injection (55 mg/kg bodyweight) The changes caused by insulin treatment (2 IU/100 g body weight, 14 days, twice daily) in both thermal groups were also investigated.STZ-diabetes leads to significant increase in blood glucose and HbA1c level, AST, ALT and ALP activities in both thermal groups (normothermic and heat acclimated), decrease in LDH activity in normothermic animals and increase in heat-acclimated ones. Treatment with insulin restores the blood glucose, HbA1c and enzymes activities regardless of the previous thermal exposure.Prolonged acclimation of control animals to elevated ambient temperature resulted in significant decrease in blood glucose level, AST, ALT, ALP and LDH activities and non-significant changes in HbA1c. Compared to diabetic rats from room temperature, heat-acclimated diabetic ones have significantly higher blood glucose, AST, ALP and LDH activity, lower HbA1c concentration and no significant changes in ALT. Most of the changes observed in heat-acclimated insulin-treated diabetic rats did not significantly differ compared to those from room temperature.The overall two-way ANOVA analyses showed that diabetic state causes significant changes in the blood glucose, HbA1c, AST, ALT and ALP activity, while heat acclimation causes significant changes only in HbA1c level and AST activity. Both of the factors (diabetic state and heat acclimation) have significant common effects on AST, ALP and LDH activity.     

Biochemical response to colloidal bismuth subcitrate

In the present study, an investigation was undertaken to assess the efficacy on serum enzymes of colloidal bismuth subcitrate (CBS). CBS was administered with injections to male rats in 100-, 200-, 400-, 500-, and 1000-μg/L doses of bismuth. Rats were anesthetized at different intervals (24, 48, and 72 h) after CBS injections. The levels of serum enzymes were determined. Aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase (ALP), and creatine kinase (CK) levels significantly increased after all CBS treatments without dependence on time. All doses of bismuth significantly affected the lactate dehydrogenase (LDH) in serum after 72 h. The lowest doses were the most toxic on ALT and LDH. These data suggest that treatment with CBS can provide evidence for a possible marker of liver toxicity although there is no evidence of liver accumulation of bismuth in the present study.     

Time dependent study to evaluate the efficacy of zinc on hepatic marker enzymes and elemental profile in serum and liver of protein deficient rats

This study was designed to determine the time dependent protective effects of zinc sulfate on the serum and liver marker enzymes along with elemental profile in protein deficient Sprauge Dawley (S.D.) female rats. Zinc sulfate in the dose of 227 mg/l in drinking water was administrated to normal control as well as protein deficient rats for a total duration of 8 weeks. The effects of different treatments were studied on enzymes like alkaline phosphatase (ALP), aspartate aminotransferases (AST) and alanine aminotransferases (ALT) in rat serum at different time intervals of 1, 2, 4 and 8 weeks and in the rat liver at the end of study. The status of different essential elements in liver was also studied. The serum ALP activity got significantly depressed when estimated at the intervals of 4 and 8 weeks. Activity of serum ALT was significantly increased after 4 weeks interval in protein deficient rats and the increasing trend continued upto 8 weeks of protein deficiency. On the other hand, activity of AST showed a significant increase just after 2 weeks and activity continued to be increased up to 8 weeks. Moreover activities of all the hepato marker enzymes showed a significant increase in liver of protein deficient rats. Interestingly, supplementation of Zn to protein deficient rats helped in regulating the altered activities of ALP, AST and ALT both in serum and liver. However, zinc treatment alone to normal rats did not indicate any significant change in the activities of all the enzymes in liver as well serum except at the interval of 2 weeks where a marginal increase in the activity of AST was seen. It has also been observed that concentrations of zinc, copper, iron and selenium were found to be decreased significantly in protein deficient animals. However, the levels of these elements came back to within normal limits when zinc was administrated to protein deficient rats. Published online December 2004     

AROMATIC AMINOTRANSFERASE ACTIVITY OF RAT BRAIN CYTOPLASMIC AND MITOCHONDRIAL ASPARTATE AMINOTRANSFERASES

Abstract— Mitochondrial and cytoplasmic forms of aspartate aminotransferase were purified from rat brain homogenates and tested for their ability to catalyze transamination of various aromatic amino acids. The mitochondrial enzyme exhibited activity toward tyrosine and phenylalanine with 2-oxoglutar-ate as acceptor, although the specific activities were less than 1% of the corresponding aspartate activity when all substrates were 10 mM. Even less activity was seen with DOPA, 5-hydroxytryptophan and tryptophan. The cytoplasmic aspartate aminotransferase was active toward tryptophan, 5-hydroxytryptophan and DOPA, but these transaminations were favored by pyruvate or oxaloacetate rather than 2-oxoglutarate as keto acid. Based on co-migration of aromatic activities with the respective aspartate aminotransferases during isoelectric focusing and based on equal sensitivities of aromatic transamination and aspartate transamination to inhibition by vinylglycine, it was concluded that all activities resided in the aspartate aminotransferase enzymes. Some doubt exists, however, as to the physiological significance of these alternate activities in view of the requirement that aromatic amino acids must compete with aspartate for transamination by these enzymes.     

Cytoplasmic enzyme activities involved in energy and amino acid metabolism in pathological human renal cortex

Enzyme levels of lactate dehydrogenase (LDH), alpha-hydroxybutyrate dehydrogenase (HBDH), aspartate aminotransferase (AST) and alanine aminotransferase (ALT) were measured in the cytosol of renal cortex samples from either normal and pathologic kidney tissue. The mean enzyme activity values, expressed in Units per gram of cytosolic protein decreased in the following order: normal cortex (LDH = 4,299 +/- 654; AST = 522 +/- 101; ALT = 197 +/- 44). chronic pyelonephritis (LDH = 2,360 +/- 876; AST = 297 +/- 117; ALT = 90 +/- 48), hydronephrosis (LDH = 2,208 +/- 1,264; AST = 279 +/- 165; ALT = 82 +/- 61), pyonephrosis (LDH = 1,410 +/- 596; AST = 158 +/- 69; ALT = 23.4 +/- 16.4) and renal tuberculosis (LDH = 1,149 +/- 481; AST = 93 +/- 34; ALT = 5.6 +/- 2.8). The decrease in the enzyme activities paralleled tissue damage and it was shown to affect cellular functionality in relation with energy and amino acid metabolism.     

Individual differences in plasma ALT, AST and GGT: contributions of genetic and environmental factors, including alcohol consumption

The causes of individuality of the plasma enzymes alanine aminotransferase (ALT; EC 2.6.1.2), aspartate aminotransferase (AST; EC 2.6.1.1) and gamma-glutamyl transferase (GGT; EC 2.3.2.2) were investigated in a study of 206 pairs of twins. Between-person variance was greater in men than women, while within-person variation was similar in both sexes. Plasma ALT and AST levels were affected by genetic factors, while GGT was affected by some environmental factor shared by co-twins. In the men, alcohol intake had a significant but small effect on all three enzyme levels, and since alcohol consumption was highly heritable, this appeared as a genetic influence on enzyme activities. The major factors involved in the observed correlations between these enzymes were a non-shared environmental factor other than alcohol affecting ALT, AST and GGT, and a genetic factor affecting only ALT and AST.     

DIFFERENCES IN THE REGULATION OF TYROSINE AMINOTRANSFERASE IN BRAIN AND LIVER

Abstract— l -Tyrosine:2-oxoglutarate aminotransferase (EC 2.6.1.5) activity in rat brain is not regulated in the same way as in rat liver. No diurnal rhythm in the activity of the cerebral enzyme was found in rats fed ad lib. although there was a marked diurnal variation in the activity of the hepatic enzyme. In adrenalectomized rats, hydrocortisone and glucagon induced the enzyme in liver but had no effect on the enzyme in brain. In normal rats, treatment with reserpine or exposure to cold elevated the activity of the hepatic enzyme without affecting the enzyme in brain. Thus, the tyrosine aminotransferase of brain differed from the enzyme in liver since it did not exhibit diurnal variations of activity and was not affected by hormones, drugs, or stress.     

Antihyperglycemic and antioxidant effects of a flavanone, naringenin, in streptozotocin–nicotinamide-induced experimental diabetic rats

In the present study, the putative antihyperglycemic and antioxidant effects of a flavanone, naringenin, were evaluated in comparison with those of glyclazide, a standard drug for therapy of diabetes mellitus. Diabetes was induced experimentally in 12-h-fasted rats by intraperitoneal injections of first streptozotocin (50 mg/kg b.w.) and then of nicotinamide (110 mg/kg b.w.) after a 15-min interval. Untreated diabetic rats revealed the following in comparison with normal rats: significantly higher mean levels of blood glucose and glycosylated hemoglobin, significantly lower mean levels of serum insulin, significantly lower mean activities of pancreatic antioxidant enzymes (superoxide dismutase, catalase, glutathione peroxidase, glutathione-S-transferase), significantly lower mean levels of plasma non-enzymatic antioxidants (reduced glutathione, vitamin C , vitamin E), significantly elevated mean levels of pancreatic malondialdehyde (MDA) and significantly elevated mean activities of serum alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP) and lactate dehydrogenase (LDH). Following oral administration of naringenin (50 mg/kg b.w./day) to diabetic rats for 21 days, the following observations were made in comparison with untreated diabetic rats: significantly lower mean levels of fasting blood glucose and glycosylated hemoglobin, significantly elevated serum insulin levels, significantly higher mean activities of pancreatic enzymatic antioxidants, significantly higher mean levels of plasma non-enzymatic antioxidants, lower mean pancreatic tissue levels of MDA and lower mean activities of ALT, AST, ALP and LDH in serum. The values obtained in the naringenin-treated animals approximated those observed in glyclazide-treated animals. Histopathological studies appeared to suggest a protective effect of naringenin on the pancreatic tissue in diabetic rats. These results suggest that naringenin exhibits antihyperglycemic and antioxidant effects in experimental diabetic rats.     

Arginase as a useful factor for the diagnosis of colorectal cancer liver metastases

The present work is a continuation of studies on arginase as a marker in the diagnosis of colorectal cancer liver metastases (CRCLM). The purpose of the study was the evaluation of the arginase test in comparison with other colorectal cancer tests such as CEA, CA 19-9 and biochemical markers of liver function such as aspartate aminotransferase (AST) and alanine aminotransferase (ALT). The studies were conducted on blood serum from 85 patients with CRCLM obtained one to two days before tumor resection. The control group comprised 140 healthy blood donors and 81 patients with various non-malignant gastrointestinal diseases. Raised arginase activity was observed in serum of 85% of CRCLM patients, whereas elevated levels of CEA and CA 19-9 were found in 63% and 42% of patients, respectively. The combination of CEA or CA 19-9 with the arginase assay improved their sensitivity, but the sensitivity of the combined parameters was not higher than that of the arginase test itself. AST and ALT activities were increased in about 30% of CRCLM patients. The specificity of the arginase test calculated for 221 control subjects was 76%. It can thus be concluded that the determination of serum arginase activity can be helpful in the diagnosis of patients with colorectal cancer liver metastases.     

Laboratory assessment of hepatic injury in the woodchuck (Marmota monax)

Normal reference values for total serum protein, albumin, cholesterol, alanine aminotransferase (ALT), aspartate aminotransferase (AST), sorbitol dehydrogenase (SDH), gamma glutamyl transferase (GGT), alkaline phosphatase (AP), and total bilirubin were established in 48 clinically healthy woodchucks. To validate the use of these biochemical tests in the woodchuck for assessment of liver injury, carbon tetrachloride was administered to produce hepatocellular necrosis and the common bile duct was surgically occluded to produce cholestasis. Biochemical tests were performed prior to experimental treatment and thereafter in surviving woodchucks for a period of 6 weeks. There were marked increases in the serum activities of AST, ALT, and SDH following carbon tetrachloride administration and all 3 enzymes appeared to be useful markers of acute hepatocellular injury. The predominate biochemical abnormalities in woodchucks with bile duct obstruction were hyperbilirubinemia, hypercholesterolemia and increased serum AP and GGT activities. The increase of GGT occurred earlier following bile duct obstruction and the magnitude of increase was greater than that of AP, suggesting that GGT would be the preferred serum enzyme test in the woodchuck for assessment of cholestatic liver injury.