Isoelectric spectra of human serum albumin in healthy subjects and in ischemic heart disease

Isoelectric spectra of serum albumins isolated from blood of patients with heart ischemia were studied using isoelectric focusing in borate-polyolic systems in a polyacrylamide gel. In patients with heart ischemia the amount of fractions with pI 4.3-4.9 and 5.2-7.4 is found to increase with a simultaneous decrease in the fraction with pI 4.9-5.2 as compared with these indices in healthy people from the control group. Especially pronounced changes in isoelectrophoregrams were observed for blood albumins of patients with transmural myocardium infraction.     

Effect of ethanol and probenecid on the excretory function of the cerebral choroid plexus in rats

Probenecid at a dose 100 and 200 mg/kg, i.v. has been found to decrease in a dose-dependent manner the level of radioactivity of cerebrospinal fluid (CSF) measured at 1, 15, 30 and 60 min. after the intravenous injection of 14C-tyrosine, 14C-tryptophan and 14C-DOPA. Ethanol at a dose 2 and 4 g/kg, i. p. has not changed the level of radioactivity of the CSF. It is suggested that mentioned in the literature an increased accumulation of the labeled tyrosine, tryptophan and DOPA in the brain structures after their intravenous injection is not related to the inhibitory effect of ethanol on the excretory function of the choroid plexus of the brain. On the other hand, it is concluded that probenecid is able to inhibit the excretion from the brain of some acid compounds including tyrosine, tryptophan and DOPA.     

Molecular complexation of α-hederin with hederasaponin C

The molecular complexation of triterpene glycosides α-hederin (hederagenin 3-O-α-L-rhamnopyranosyl-(1 → 2)-O-α-L-arabinopyranoside) with hederasaponin C (hederagenin 3-O-α-L-rhamnopyranosyl-(1 → 2)-O-α-L-arabinopyranosyl-28-O-α-L-rhamnopyranosyl-(1 → 4)-O-β-D-glucopyranosyl-(1 → 6)-O-β-D-glucopyranoside) was investigated for the first time using the methods of IR- and electrospray ionization mass spectroscopy. The glycosides form a complex in the 1: 1 molar ratio. The influence of complex on Avena sativa seeds germination and its ichthyotoxicity against Poecilia reticulata were studied.     

Redox regulation of copper-metallothionein

Copper (Cu) is an essential element whose localization within cells must be carefully controlled to avoid Cu-dependent redox cycling. Metallothioneins (MTs) are cysteine-rich metal-binding proteins that exert cytoprotective effects during metal exposure and oxidative stress. The specific role of MTs, however, in modulating Cu-dependent redox cycling remains unresolved. Our studies utilized a chemically defined model system to study MT modulation of Cu-dependent redox cycling under reducing (Cu/ascorbate) and mild oxidizing (Cu/ascorbate + H2O2) conditions. In the presence of Cu and ascorbate, MT blocked Cu-dependent lipid oxidation and ascorbyl radical formation with a stoichiometry corresponding to Cu/MT ratios 相似文献   

Appetizing rancidity of apoptotic cells for macrophages: oxidation,externalization, and recognition of phosphatidylserine

Programmed cell death (apoptosis) functions as a mechanism to eliminate unwanted or irreparably damaged cells ultimately leading to their orderly phagocytosis in the absence of calamitous inflammatory responses. Recent studies have demonstrated that the generation of free radical intermediates and subsequent oxidative stress are implicated as part of the apoptotic execution process. Oxidative stress may simply be an unavoidable yet trivial byproduct of the apoptotic machinery; alternatively, intermediates or products of oxidative stress may act as essential signals for the execution of the apoptotic program. This review is focused on the specific role of oxidative stress in apoptotic signaling, which is realized via phosphatidylserine-dependent pathways leading to recognition of apoptotic cells and their effective clearance. In particular, the mechanisms involved in selective phosphatidylserine oxidation in the plasma membrane during apoptosis and its association with disturbances of phospholipid asymmetry leading to phosphatidylserine externalization and recognition by macrophage receptors are at the center of our discussion. The putative importance of this oxidative phosphatidylserine signaling in lung physiology and disease are also discussed.     

Oxidative stress following traumatic brain injury in rats: quantitation of biomarkers and detection of free radical intermediates

Oxidative stress may contribute to many pathophysiologic changes that occur after traumatic brain injury. In the current study, contemporary methods of detecting oxidative stress were used in a rodent model of traumatic brain injury. The level of the stable product derived from peroxidation of arachidonyl residues in phospholipids, 8-epi-prostaglandin F(2alpha), was increased at 6 and 24 h after traumatic brain injury. Furthermore, relative amounts of fluorescent end products of lipid peroxidation in brain extracts were increased at 6 and 24 h after trauma compared with sham-operated controls. The total antioxidant reserves of brain homogenates and water-soluble antioxidant reserves as well as tissue concentrations of ascorbate, GSH, and protein sulfhydryls were reduced after traumatic brain injury. A selective inhibitor of cyclooxygenase-2, SC 58125, prevented depletion of ascorbate and thiols, the two major water-soluble antioxidants in traumatized brain. Electron paramagnetic resonance (EPR) spectroscopy of rat cortex homogenates failed to detect any radical adducts with a spin trap, 5,5-dimethyl-1-pyrroline N:-oxide, but did detect ascorbate radical signals. The ascorbate radical EPR signals increased in brain homogenates derived from traumatized brain samples compared with sham-operated controls. These results along with detailed model experiments in vitro indicate that ascorbate is a major antioxidant in brain and that the EPR assay of ascorbate radicals may be used to monitor production of free radicals in brain tissue after traumatic brain injury.     

Low-Molecular-Weight Compounds

Self-association of caffeine has been investigated using mass spectrometry. It was found that associates are composed of caffeine trimers and hexamers. The possibility of complex formation of caffeine with triterpene glycosides 3-O-α-L-rhamnopyranosyl-(1→2)-O-α-L-arabinopyranoside of hederagenin and its 28-O-α-L-rhamnopyranosyl-(1→4)-O-β-D-glucopyranosil-(1→6)-O-β-D-glucopyranosil ester have been considered. Under the experimental conditions, inclusion compounds do not form and only self-associates of caffeine and glycosides are found.     

Biological significance of the Gornoslinkinskaya Riverbed Depression in the Irtysh

Distribution of fish in the Gornoslinkinskaya Riverbed Depression in the Irtysh is considered in relation to the time of day and to the season. Fish aggregations are characterized quantitatively and by their size and species composition. The major part of the fish population of the depression consists of fish juveniles. The biological significance of the riverbed depression is polyfunctional. The universal traits of the ecosystems of large river basins and mechanisms of their occupation by fish are discussed.