Association of myocardial glutamate and aspartate pool and functional recovery of postischemic heart

The effect of low flow ischemia and subsequent reperfusion with 5.5 mM glucose or 5 mM acetate on energy metabolism and catabolism of myocardial glutamate and aspartate was studied in isolated perfused guinea pig hearts. Reperfusion with acetate was followed by low recovery of the cardiac contractile function associated with a great rise in isovolumic end-diastolic pressure. It was combined with more profound losses of tissue adenine nucleotides and the total Cr compared to reperfusion with glucose. The total glutamate and aspartate pool decreased more than two-fold compared to the initial one regardless of substrate. However, glutamate content was reduced by 58 and 38% with acetate and glucose, respectively. The expenditure of both amino acids was caused by alanine formation stimulated by glycolysis/glycogenolysis. The remaining glutamate and aspartate pool in the reperfused hearts positively correlated with adenine nucleotides (r = 0.62), the total creatine (r = 0.65), and the recovery of contractile function (r = 0.64). The results suggest that the glutamate and aspartate pool may be of critical importance for postischemic functional and metabolic recovery of the heart.     

Convergent Synthesis of the Rat Galanin and Study of Its Biological Activity

Russian Journal of Bioorganic Chemistry - The full-length rat galanin (GWTLNSAGYLLGPHAIDNHRSFSDKHGLT-NH2, G29) was prepared by the solid phase peptide synthesis using the Fmoc-strategy. The peptide...     

Modified N-Terminal Fragments of Galanin: Cardioprotective Properties and Mechanisms of Action

Biochemistry (Moscow) - The design of new drugs for treatment of cardiovascular diseases based on endogenous peptide hormones is of undoubted interest and stimulates intensive experimental...     

The bryophyte flora of northern Iturup (north-west Pacific): between the circumboreal and East Asian floristic regions

Introduction. The Kuril Islands Chain demarcates the boundary between the circumpolar and East Asian floras in the amphi-Pacific and is a trans-Oceanic migration route from warm-temperate insular East Asia to north-east Asia and Beringia. This paper reviews the flora of the northern part of Iturup Island in regards to its bryogeography and taxonomic diversity, as well as its relative position among other bryophyte floras of north-east and East Asia.

Methods. The paper uses morphological methods to identify the species composition and detrended correspondence analysis to identify the position of the northern Iturup Island in the system of local floras of the eastern, extra-tropical, Pacific.

Key results. The flora is closely related to the bryophyte floras of the southern Kurils and Hokkaido Island, but has been found to be distinctly distant from the ‘true’ cool-temperate East Asian floras, as well as from the boreal and hemiarctic floras of north-east Asia. Instead, the floras of the south Kurils and northern Hokkaido Island belong to a peculiar intermediate phytogeographic province that cannot be unambiguously placed in either the East Asian or circumboreal floristic regions. The hemiboreal character of the bryophyte flora of northern Iturup Island is in contrast to the general appearance of many of the dominant vegetation communities on the island, which are more characteristic of the hemiarctic.

Conclusion. There is no robust evidence to refer the bryophyte flora of northern Iturup either to the circumboreal or East Asian Floristic Region, the flora belongs to a unique intermediate province between the two regions.     

Adenine nucleotides, glutamate and respiratory function of heart mitochondria during acute hypoxia

The effect of acute hypoxia on adenine nucleotides, glutamate, aspartate, alanine and respiration of heart mitochondria was studied in rats. The losses of intramitochondrial adenine nucleotides (ATP+ADP+AMP) during hypoxia were related to depression of state 3 respiration supported by glutamate and malate, as well as decrease in uncoupled respiration. Hypoxia had less prominent effect on succinate-dependent state 3 respiration. Non-phosphorylating (state 4) respiratory rates and ADP/O ratios were slightly affected by oxygen deprivation. Glutamate fall in tissue and mitochondria of hypoxic hearts was concomitant with significant increase in tissue alanine and mitochondrial aspartate. The losses of intramitochondrial ATP and respiratory activity with NAD-dependent substrates during hypoxia were related to a decrease in mitochondrial glutamate. The results suggest that hypoxia-induced impairment of complex I of respiratory chain and a loss of glutamate from the matrix may limit energy-producing capacity of heart mitochondria.     

Chimeric Agonist of Galanin Receptor GALR2 Reduces Heart Damage in Rats with Streptozotocin-Induced Diabetes

Biochemistry (Moscow) - Neuropeptide galanin and its N-terminal fragments reduce the generation of reactive oxygen species and normalize metabolic and antioxidant states of myocardium in...     

Synthesis and cardioprotective properties of apelin-12 and its structural analogs

The apelin-12 and a number of its analogs, resistant to degradation of proteases, were synthesized by Fmoc- method of SPPS. By-products of synthesis were examined. It was found that serine hydroxyl group was sulfating during the final deprotection of apelin-12 (I) and its analogs. Sulfate moiety of Arg-protecting group transfer into hydroxyl group of Ser. Amount of by-product depends on presence of water in cleavage mixture. Furthermore, the final deprotection of amide analogs of apelin-12 (III, IV) is closed with formation of by-product--4-hydroxybenzylamide, its amount range on 20-8% on reaction mixture accordance HPLC data and also depend on composition of cleavage mixture. Effects of the synthesized peptides on recovery of cardiac function after ischemia were examined in a model of isolated perfused rat heart. Infusions of any of the peptides (I-V) before ischemia resulted in a significant improvement of contractile and pump function recovery compared to the control. Cardioptotective efficacy of the peptides increased in the following rank (I) < (II) = (III) < (IV) = (V).     

Novel clades of chromodomain-containing Gypsy LTR retrotransposons from mosses (Bryophyta)

Retrotransposons are the major component of plant genomes. Chromodomain-containing Gypsy long terminal repeat (LTR) retrotransposons are widely distributed in eukaryotes. Four distinct clades of chromodomain-containing Gypsy retroelements are known from the vascular plants: Reina, CRM, Galadriel and Tekay. At the same time, almost nothing is known about the repertoire of LTR retrotransposons in bryophyte genomes. We have combined a search of chromodomain-containing Gypsy retroelements in Physcomitrella genomic sequences and an experimental investigation of diverse moss species. The computer-based mining of the chromodomain-containing LTR retrotransposons allowed us to describe four different elements from Physcomitrella. Four novel clades were identified that are evolutionarily distinct from the chromodomain-containing Gypsy LTR retrotransposons of other plants.     

New single nucleotide polymorphisms of androgen receptor gene (<Emphasis Type="Italic">AR</Emphasis>) in the Russian breed of Dzhalginsky Merino sheep

This paper investigates the structure of androgen receptor gene (AR) in the Russian breed of Dzhalginsky Merino sheep. Polymorphisms of the gene were detected using NimbleGen sequencing technology (Roche, United States). Eight single nucleotide polymorphisms (SNPs) and two insertions were detected. Five of these SNPs (c.335T>G, c.339G>A, c.342T>C, c.2491-327T>A, and c.2491-325A>T) and both insertions were identified for the first time. Three SNPs and the insertions are located in the coding part of exon. Insertion c.336_337 is found in most of the animals of this breed and can be used as a genomic marker of the breed. Animals with mutant variant of SNP c.1496+15T>C have significantly lower live weight and body size compared with the wild type genotype. This SNP can be used as a genetic marker of meat production in marker-assisted selection.     

A 1H NMR study of succinate synthesis from exogenous precursors in oxygen-deprived rat heart mitochondria

Succinate synthesis from exogenous malate, alpha-ketoglutarate, oxaloacetate and L-glutamate in isolated oxygen-deprived rat heart mitochondria was studied using 1H NMR. The highest rate of succinate synthesis was observed during incubation of mitochondria with a mixture of L-glutamate and oxaloacetate. When mitochondria were incubated with [U-13C] glutamate and oxaloacetate the [U-13C] succinate/succinate and aspartate/succinate ratios were equal to 2. This suggests that the succinate produced from [U-13C] alpha-keto-glutarate formed via transamination of [U-13C] glutamate with oxaloacetate by aspartate aminotransferase exceeds twofold that synthesized via oxaloacetate reduction. It may thus be expected that GTP yield in a reaction catalyzed by the succinic thiokinase will be 2 times higher that of ATP production coupled with NADH-dependent fumarate reduction.