Liver hydrolysate assists in the recovery from physical fatigue in a mouse model

It is reported that liver hydrolysate (LH) enhances liver function. However, the effects of LH on physical fatigue are unknown. The aim of this study was to investigate the effect of LH on alterations in locomotor activity and energy metabolism such as 5'-AMP-activated protein kinase (AMPK), glycogen content, and blood lactic acid, after forced walking. Adult male ddY mice were used. Locomotor activity, AMPK phosphorylation, and glycogen content in the liver and soleus muscle, as well as blood lactic acid were determined following LH treatment before and/or after forced walking. The locomotor activity significantly decreased after forced walking for 3 h. Two administrations of LH (30 or 100 mg/kg) significantly increased the locomotor activity, while a single administration either before or after forced walking did not show any specific effect. Administering LH twice activated AMPK in the liver and soleus muscle. Glycogen levels significantly decreased in both the liver and soleus muscle after forced walking, whereas the blood lactate level significantly increased. In contrast, administering LH twice increased muscle glycogen and decreased blood lactic acid. These findings indicate that LH produced an anti-fatigue effect and that this effect appears to involve the efficient glycogen utilization through activation of AMPK.

Microdosimetric evaluation of the neutron field for BNCT at Kyoto University reactor by using the PHITS code

In this study, microdosimetric energy distributions of secondary charged particles from the (10)B(n,α)(7)Li reaction in boron-neutron capture therapy (BNCT) field were calculated using the Particle and Heavy Ion Transport code System (PHITS). The PHITS simulation was performed to reproduce the geometrical set-up of an experiment that measured the microdosimetric energy distributions at the Kyoto University Reactor where two types of tissue-equivalent proportional counters were used, one with A-150 wall alone and another with a 50-ppm-boron-loaded A-150 wall. It was found that the PHITS code is a useful tool for the simulation of the energy deposited in tissue in BNCT based on the comparisons with experimental results.

Inhibition of xanthine oxidase and xanthine dehydrogenase by nitric oxide. Nitric oxide converts reduced xanthine-oxidizing enzymes into the desulfo-type inactive form

Xanthine oxidase (XO) and xanthine dehydrogenase (XDH) were inactivated by incubation with nitric oxide under anaerobic conditions in the presence of xanthine or allopurinol. The inactivation was not pronounced in the absence of an electron donor, indicating that only the reduced enzyme form was inactivated by nitric oxide. The second-order rate constant of the reaction between reduced XO and nitric oxide was determined to be 14.8 +/- 1.4 M-1 s-1 at 25 degrees C. The inactivated enzymes lacked xanthine-dichlorophenolindophenol activity, and the oxypurinol-bound form of XO was partly protected from the inactivation. The absorption spectrum of the inactivated enzyme was not markedly different from that of the normal enzyme. The flavin and iron-sulfur centers of inactivated XO were reduced by dithionite and reoxidized readily with oxygen, and inactivated XDH retained electron transfer activities from NADH to electron acceptors, consistent with the conclusion that the flavin and iron-sulfur centers of the inactivated enzyme both remained intact. Inactivated XO reduced with 6-methylpurine showed no "very rapid" spectra, indicating that the molybdopterin moiety was damaged. Furthermore, inactivated XO reduced by dithionite showed the same slow Mo(V) spectrum as that derived from the desulfo-type enzyme. On the other hand, inactivated XO reduced by dithionite exhibited the same signals for iron-sulfur centers as the normal enzyme. Inactivated XO recovered its activity in the presence of a sulfide-generating system. It is concluded that nitric oxide reacts with an essential sulfur of the reduced molybdenum center of XO and XDH to produce desulfo-type inactive enzymes.

Enhanced absorption of calcium after oral administration of maltitol in the rat intestine

The enhancing effects of maltitol (alpha-D-glucopyranosyl-1,4-sorbitol) on absorption of calcium by the rat intestine have been studied by use of [45Ca]CaCl2 in-vivo. After intragastric administration of [45Ca]CaCl2 solution with maltitol, plasma 45Ca concentration remained at the maximum level for more than 80 min, whereas for animals given [45Ca]CaCl2 solution without maltitol, plasma 45Ca concentration declined sharply after the peak. Determination of 45Ca radioactivity remaining in the various segments of the gastrointestinal tract revealed that administration of maltitol elicited slower gastric emptying and slower intestinal transit, resulting in extensive 45Ca distribution along the small intestine throughout the experimental period. The luminal contents of the small intestine were significantly higher in rats given maltitol than in the control group. These results suggest that the enhancing action of maltitol on intestinal calcium absorption could be attributed to reduced gastrointestinal calcium transit and increased luminal fluid content, presumably because of the osmotic activity of maltitol; this would not only accelerate the dissolution of calcium into the increased luminal contents, but also enable a larger area of the small intestine to absorb calcium for a longer period of time.

The importance of polymorphonuclear leukocytes in lipopolysaccharide-induced superoxide anion production and lung injury: ex vivo observation in rat lungs

The purpose of this study is to determine if the polymorphonuclear leukocyte (PMN) is a major causative agent for lipopolysaccharide (LPS)-induced lung injury and responsible for the excess production of superoxide anion in the lung. We measured superoxide anion production from the lung and pulmonary capillary permeability in rats with and without PMN depletion. The superoxide anion production from the lung was measured using a purpose-built ex vivo chemiluminescence apparatus. Pulmonary capillary permeability was evaluated by the Evans blue dye extravasation method. PMN sequestration was determined by counting PMNs in histologic tissue specimens using microscopy. All rats received 3 mg/kg LPS intravenously. Examinations were undertaken at 2, 6, and 12 h after the LPS injection. The PMN-depleted group received cyclophosphamide 4 days before the LPS injection, which resulted in a PMN count of less than 200 cells/microliter. In rats without PMN depletion, Evans blue dye extravasation increased significantly at 12 h after the LPS injection; PMN sequestration increased at 2, 6, and 12 h after the LPS injection; and superoxide anion production increased at 6 h and remained elevated at 12 h after the LPS injection. The increased permeability, PMN sequestration, and superoxide anion production were not seen in the PMN-depleted group. The contribution of the xanthine/xanthine oxidase system and alveolar macrophages to the observed superoxide anion production was negligible. We conclude that, in rats, the PMN is a major causative agent in LPS-induced lung injury and is responsible for the excess production of superoxide anion in the lung.

Early reperfusion induces alveolar injury in pulmonary embolism

STUDY OBJECTIVE

To observe (1) whether the reperfusion is one of the causes underlying the development of diffuse alveolar injury following pulmonary embolism, and (2) whether polymorphonuclear leukocyte (PMN) accumulation occurs in the reperfused lobe, and (3) whether the production of superoxide is increased from cells obtained by BAL.

DESIGN

The condition of pulmonary embolism was simulated by occluding the pulmonary artery branch using a balloon catheter in anesthetized closed-chest dogs. The occlusion was maintained for 24 h in the occlusion group, and a 2-h period of occlusion was followed by reperfusion in the reperfusion group. Histologic examination was performed at 24 h after occlusion in both groups (n = 8). Using a different group of dogs (n = 12), local cellular changes in the occluded and reperfused lobes were evaluated through BAL performed at 1, 2, and 3 h after reperfusion in the reperfusion group and at 3 h after occlusion in the occlusion group. Superoxide generation from BAL cells was measured by the chemiluminescence method.

RESULTS

There was no histologic evidence of alveolar injury in the occluded lobe, but there were numerous leukocytes and erythrocytes along with exudate and damaged alveoli in the reperfused lobe. In the BAL study, the total cell counts recovered by BAL remained unchanged in all groups. However, the number of PMNs increased significantly in the late stages of reperfusion. Enhanced superoxide generation was observed in BAL cells obtained from reperfused lobe.

CONCLUSION

Reperfusion is one of the causes underlying the development of alveolar injury in pulmonary embolism by triggering immigration of PMNs to alveoli, which results in the increased superoxide generation in BAL cells.

Effects of the structures of polyoxyethylene alkyl ethers on uptake of butyl p-hydroxybenzoate by Escherichia coli and its antibacterial activity

The effects of the structures of non-ionic surfactants on the uptake of butyl p-hydroxybenzoate (BP) into Escherichia coli cells and its antibacterial activity were systematically studied using polyoxyethylene alkyl ethers (PAEs) possessing various oxyethylene and hydrocarbon chain lengths. The uptake of BP into bacterial cells in an aqueous PAE solution was proportional to free BP in an aqueous phase, depending on the structures of PAEs. The antibacterial activity of BP decreased in the presence of PAEs, whereas it was greater than that anticipated from free BP. However, only PAE with 12 carbons in the hydrophobic group caused unusual increases in the uptake and antibacterial activity of BP, and the surfactant was more extensively incorporated into bacterial cells, differing from other PAEs, which were much less incorporated. The PAEs were thus concluded to increase the susceptibility of bacteria against BP due to direct interactions with the cells. Particularly, the PAE with 12 carbons in the hydrophobic group, which penetrated abundantly into the cells, might result in an increase in the fluidity of the cellular lipid matrix and a decrease in the resistance of drug permeation.

Relationship between uptake of p-hydroxybenzoic acid esters by Escherichia coli and antibacterial activity

The relationship between the uptake and antimicrobial activity of p-hydroxybenzoic acid esters (parabens) was studied using Escherichia coli. The uptake into bacterial cells and the antibacterial activity of parabens were logarithmically proportional to the carbon number of the alkyl group from methyl to butyl paraben. The free energy change for the transfer of the methylene group of parabens from the aqueous to the cell phase was less than that obtained from the n-hexane and n-octanol-water partition systems. This demonstrates that the hydrophilicity of the cells is larger than n-hexane and n-octanol. The uptake of hydrophobic ethyl benzoate was less than that of the more hydrophilic butyl paraben possessing a phenolic hydroxyl group. Parabens may thus be incorporated into cells by both hydrophobic and hydrophilic interactions. The apparent concentration of parabens in the bacterial cells required to produce the same antibacterial activity decreased logarithmically with an increasing carbon number of the alkyl group. The dependence of the antibacterial activity of parabens on the alkyl chain length may thus be concluded to be due to the alkyl group, not only for uptake into bacterial cells but also for accumulation or concentration on biological receptors after incorporation into the cells.

Serum dehydroepiandrosterone (DHEA) and DHEA-sulfate (DHEA-S) in Alzheimer's disease and in cerebrovascular dementia

A decreased concentration of dehydroepiandrosterone sulfate (DHEA-S) in patients with Alzheimer's disease (AD) has been reported but is still controversial. In the present study, serum concentrations of DHEA and DHEA-S were determined in 19 patients with AD, 21 patients with cerebrovascular dementia (CVD) and 45 age- and gender matched elderly control individuals from the Japanese community at large. Serum concentration of DHEA among controls, patients with AD and patients with CVD did not significantly differ from one another. However, patients with AD and patients with CVD were found to have lower concentration of serum DHEA-S and a lower DHEA-S/DHEA ration compared to normal control individuals. No significant difference was observed in the concentration of serum DHEA-S or the DHEA-S/DHEA ratio between patients with AD and those with CVD. These results suggest that reduced concentrations of serum DHEA-S may not be unique to AD, but instead reflect a common phenomenon in dementing diseases. However, since serum concentration of DHEA in these patients remained unchanged, the significance of DHEA in dementia remains unclear.

Peroxynitrite-induced cardiac myocyte injury

The effects of peroxynitrite (ONOO-) on cultured cardiac myocytes were examined by simultaneous measurements of intracellular Ca2+ ([Ca2+]i) and contractile function. On exposure to 0.2 mM ONOO-, [Ca2+]i increased to beyond the systolic level within 5 min with a concomitant decrease in spontaneous contraction of myocytes followed by complete arrest. Addition of a L-type Ca2+ channel blocker or removal of extracellular Ca2+ prevented the ONOO(-)-induced increase in [Ca2+]i, indicating that the increase in [Ca2+]i was caused by the enhanced influx of Ca2+ through the plasma membrane and not by the enhanced release from sarcoplasmic reticulum (SR). Plasma membrane fluidity and concentration of the thiobarbiturate acid-reactive substance (TBARS) in the cells remained unchanged by the ONOO- treatment. The complete cessation of contraction of myocytes persisted even under the massive increase in [Ca2+]i, which was induced by an additional saponin (5 microM) treatment. In conclusion, ONOO- increases [Ca2+]i in myocytes through disturbance of Ca2+ transport systems in the plasma membrane and impairs contractile protein.

[Results of annual health examination for the aged provided by the law that are predictive of increased mortality risk]

Possible risk factors associated with mortality were studied in a community using data derived from annual mass health examinations for the aged mandated by law. A total of 1,804 adults (685 men and 1,119 women) aged 40 or older in A-town, located on Tsushima Island, Nagasaki Prefecture, Japan who had participated in annual health examinations at least once between 1984 and 1990, were followed for a mean period of 4.9 years. After adjustment for age using Cox proportional hazards models, in men liver dysfunction (aspartate aminotransferase > 40 U/l or alanine aminotransferase > 35 U/l), fasting blood glucose > or = 110 mg/dl and glucosuria, and in women serum creatinine > or = 1.2 mg/dl, fasting blood glucose > or = 110 mg/dl and proteinuria were found to be associated with a significantly increased risk of total mortality. In multivariate analysis using all independent variables that were significantly associated with mortality in age-adjusted bivariate analysis, in men liver dysfunction and hyperglycemia, and in women hypercreatininemia and hyperglycemia, were significant predictors of mortality. These independent variables remained significant or marginally significant predictors of total mortality even after excluding the effects of 3 pancreatic cancer cases with liver dysfunction or hyperglycemia or 12 deaths within the first year of follow-up, being associated with at least two-fold increased hazard rate ratios. From these results, it is recommended that persons with these risk factors be followed intensively and counseled by public health personnel to modify risk factors.

Nitric oxide reversibly suppresses xanthine oxidase activity

The effects of nitric oxide (NO) on xanthine oxidase (XOD) activity and the site(s) of the redox center(s) affected were investigated. XOD activity was determined by superoxide (O2-) generation and uric acid formation. NO reversibly and dose-dependently suppressed XOD activity in both determination methods. The suppression interval also disclosed a dose-dependent prolongation. The suppression occurred irrespective of the presence or absence of xanthine; indicating that the reaction product of NO and O2-, peroxynitrite, is not responsible for the suppression. Application of synthesized peroxynitrite did not affect XOD activity up to 2 microM. Methylene blue, which is an electron acceptor from Fe/S center, prevented the NO-induced inactivation. The results indicate that NO suppresses XOD activity through reversible alteration of the flavin prosthetic site.

Pancreastatin-like immunoreactivity of cerebrospinal fluid in patients with Alzheimer type dementia: evidence of aberrant processing of pancreastatin in Alzheimer type dementia

The concentrations of pancreastatin-like immunoreactivity (PST-LI) of the cerebrospinal fluid (CSF) were measured in the patients with Alzheimer type dementia (ATD) and in age-matched normal subjects. The mean PST-LI concentration in the CSF of ATD patients was significantly lower than that of normal subjects. Gel chromatographic analysis revealed that the main PST-LI peak of ATD's CSF eluted at molecular weight (MW) 13.5 kDa. However, the age-related change of the molecular forms of PST-LI in CSF was observed in normal subjects as following; PST-LI in neonatal CSF showed one peak at MW 13.5 kDa, that of 16-64-year-old showed two peaks at MW 13.5 and 5.4 kDa, however, only one main peak was shown at MW 5.4 kDa in the CSFs of 72-85-year-old. These findings suggest that the production of PST-LI was decreased and the proteolytic cleavage, which should process big PST to PST (1-52) in normal subjects, was altered to that of neonatal type in the CNS of the patients with ATD.

The reactions of 3,5-dibromo-4-nitrosobenzenesulfonate and its biological applications

Recently, 5,5-dibromo-4-nitrosobenzenesulfonate (DBNBS) has been applied to detect biological free radicals. However, DBNBS has various non-specific reactions which lead to preplexing results. Thus, we investigated some basic reactions of DBNBS in combination of other nitroso spin traps to assign DBNBS spin adducts derived from human platelets which presumably related to the endothelium-derived relaxing factor (EDRF). The collagen activated platelets yielded four spin adducts (ST, LT, SS, and LS) in the presence of DBNBS (40 mM). The broad triplet due to ST was also observed by bubbling NO gas into a DBNBS solution. To identify ST, nitrosobenzene (NB) in dry dioxane was mixed with NO-saturated dioxane. The NB-NO spin adduct was observed but decomposed into diphenyl aminoxyl by the addition of H2O indicating that the primary adduct formed by the reaction of NO and DBNBS is unstable and turns into a dimerization product. Although ST could be eliminated by the inhibitor of EDRF, ST was shown to be produced by non-specific reactions. Another triplet was assigned to an S-centered radical because thiyl radicals which were generated from either the decomposition of S-nitrosothiol, or glutathione oxidation exhibited almost identical triplet signals. The other two sextets were assigned to C-centered radical adducts. Thus, DBNBS detected NQ-related, S-centered, and two C-centered radicals derived from human platelets. Special cautions are necessary for the identification of DBNBS spin adducts in a biological system to exclude artifactual radicals.

Purification of endogenous inhibitors of [3H]flunitrazepam binding from bovine brain

Endogenous substances which inhibited the binding of [3H]flunitrazepam ([3H]FNZ) to bovine synaptosomal membranes have been purified from the hot acetic acid extracts of the bovine brain. Three peaks of inhibitory activity were obtained by Sephadex G-10 gel chromatography. Two of the peaks (Peak 2, and Peak 3) which had lower molecular weights than that of peak 1 were identified as inosine and hypoxanthine by TLC methods. Another peak (Peak 1) was further purified to homogeneity using both cation and anion ion-exchange chromatography and the following two-step reversed-phase HPLC. The purified substance inhibited the [3H]FNZ binding dose-dependently and competitively but did not have an effect on the binding of the peripheral-type BZ ligand [3H]Ro 5-4864. It was also shown that the substance was heat-stable and resistant to proteolytic degradation (trypsin, alpha-chymotrypsin, pronase). However, a significant loss of inhibitory activity to [3H]FNZ binding was observed after acid hydrolysis. Molecular weight estimates based on gel filtration methods were less than 500 dalton, and the maximal ultraviolet absorption peak was at 314 nm. These results suggest that this substance is a new endogenous ligand for the central BZ receptor and may play an important role in regulating the GABAergic tone in the central nervous system.

[3H]MK-801 binding to forebrain of E1 (epileptic) and non-epileptic strains of mice

The El mouse is an animal model with genetically determined epilepsy. To elucidate the mechanism of convulsive seizures in El mice, the effects of L-glutamate and glycine on the binding of (+)[3H]MK-801 were studied in well-washed membranes from forebrains of ddY, BALB/c and El (stimulated and non-stimulated) mice. There were no significant differences in affinity (Kd) or density (Bmax) among the 4 groups of mice under basal conditions. Incubation in the presence of L-glutamate and/or glycine led to an increase in apparent density, but not in affinity. No significant change was observed in either Kd, Bmax, or the percentage increase in (+)[3H]MK-801 binding amount the 4 groups in the presence of L-glutamate and/or glycine. These results suggest that the seizure susceptibility of El mice cannot be explained by changes in affinity or density of the NMDA receptor/channel complex.

Effects of dietary zinc status on seizure susceptibility and hippocampal zinc content in the El (epilepsy) mouse

The effects of dietary zinc status on the development of convulsive seizures, and zinc concentrations in discrete hippocampal areas and other parts of the limbic system were studied in the El mouse model receiving zinc-adequate, zinc-deficient or zinc-loaded diets. Seizure susceptibility of the El mouse was increased by zinc deficiency, and decreased by zinc loading, while an adequate diet had no effect. Zinc loading was accompanied by a marked increase in hippocampal zinc content in the El mouse. Conversely, hippocampal zinc content declined in the El mouse fed a zinc-deficient diet. These results suggest that zinc may have a preventive effect on the development of seizures in the El mouse, and hippocampal zinc may play an important role in the pathophysiology of convulsive seizures of epilepsy.

Monoaminergic regulation of the levels of beta-endorphin-like immunoreactivity (beta-ENDi) in rat hypothalamic nuclei

To examine the role of monoamines in regulating beta-endorphin levels in discrete brain nuclei, the levels of beta-endorphin-like immunoreactivity (beta-ENDi) were determined in the hypothalamic nuclei of rats 2 h after they were treated with monoaminergic drugs. Sulpiride decreased the levels of beta-ENDi in the nucleus paraventricularis, nucleus arcuatus and median eminence. Domperidone decreased the levels of beta-ENDi in the nucleus aracuatus and median eminence. L-DOPA increased the levels of beta-ENDi in the nucleus anterior hypothalami and median eminence. Phenylephrine or prazosine did not alter the levels of beta-ENDi. Yohimine decreased the levels of beta-ENDI in the nucleus anterior hypothalami. Isoproterenol increased the levels of beta-ENDi in the nucleus arcuatus, and propranolol reversed this effect. These results suggest that dopamine and noradrenaline (via beta-adrenoceptors) may regulate beta-endorphinergic neurons in the rat hypothalamus.

Zinc content in discrete hippocampal and amygdaloid areas of the epilepsy (El) mouse and normal mice

In the present study, zinc content was determined in discrete hippocampal and amygdaloid areas of 3 strains of mice (El, ddY and CBA) using an atomic absorption spectrophotometer. Zinc content was significantly lower in the dentate area of El strain compared to ddY and CBA strains. The El mouse is considered an animal model for epilepsy and the seizures in this mouse appear to originate in the hippocampus. The results suggest the possible involvement of hippocampal zinc in the pathophysiology of convulsive seizures in the epileptic mouse.

Behavior of lead and zinc in plasma, erythrocytes, and urine and ALAD in erythrocytes following intravenous infusion of CaEDTA in lead workers

To evaluate the effect of calcium disodium ethylenediamine tetraacetate (CaEDTA) on concentrations of lead and zinc in plasma, erythrocytes, whole blood, and urine, we administered CaEDTA by intravenous infusion for 1 hr to seven lead workers with blood lead concentrations of 46-67 micrograms/100 g (mean 54 micrograms/100 g). The plasma lead concentration (PPb) and the mobilization yield of lead in urine by CaEDTA were highest during the period between 1 and 2 hr after the infusion was started. In contrast, the lead concentration in erythrocytes (EPb) and in whole blood (BPb) remained unchanged during the 24 hr following infusion. Plasma zinc concentration (PZn) also fell rapidly following CaEDTA infusion; the decline was followed by a gradual rise in the zinc concentration in erythrocytes (EZn) without alteration in the zinc in whole blood. The mobilization yield of zinc in urine by CaEDTA (MZn) reached its highest level within 1 hr after the start of the infusion. Delta-aminolevulinic acid dehydratase (ALAD) activity in erythrocytes gradually increased for 5 hr following CaEDTA infusion. These observations suggest that (1) PPb concentration is a more sensitive indicator of the body burden of chelatable lead than is either BPb or EPb; (2) MZn is mobilized mostly from plasma during the first several hours following the start of CaEDTA infusion, and the fall in PZn concentration following infusion is compensated first by a rise in EZn concentration and then by an immediate redistribution of zinc in other organs to the blood; and (3) Pb-inhibited ALAD activity is reactivated by the increased EZn during and shortly after CaEDTA infusion.