[Structural and functional changes in rat liver mitochondria under calcium ion loading in the absence and presence of flavonoids]. / Strukturnye i funktsional'nye izmeneniia mitokhondrii pecheni krys pri nagruzke ionami kal'tsiia v otsutstvie i v prisutstvii flavonoidov.

The aim of the present work was to elucidate the mechanisms of calcium ion-induced impairments of the ultrastructure and functional activity of isolated rat liver mitochondria in the absence and presence of a number of flavonoids in vitro. In the presence of exogenous Ca²âº (20-60 µM), mitochondrial heterogeneity in size and electron density markedly increased: most organelles demonstrated a swollen electron-light matrix, bigger size, elongated cristae and a reduced their number, a damaged native structure of the inner membrane up to its detachment, and some mitochondria showed a more electron-dense matrix (condensed mitochondria). The calcium-induced opening of the mitochondrial permeability transition pores (MPTP) resulted in the ultrastructural disturbances and in the effective inhibition of the respiratory activity of rat liver mitochondria. The flavonoids (10-25 µM) naringenin and catechin, dose-dependently inhibited the respiratory activity of mitochondria and stimulated the MPTP opening in the presence of Ca²âº ions. Since Ruthenium red, an inhibitor of the mitochondrial Ca²âº uniporter, effectively prevented Ca²âº-induced MPTP opening both in the absence and presence of flavonoids, we hypothesized that the effect of flavonoids on the MPTP opening could be mediated by stimulation of the Ca²âº uniporter.

[Taurine induces an imbalance in the pool of neuroactive amino acids and biogenic amines in regions of the brain]. / Taurin indutsiruet disbalans pula neiroaktivnykh aminokislot i biogennykh aminov v otdelakh golovnogo mozga.

The paper deals with the consequences of exogenous taurine (Tau) administration (650 mg/kg, i.p., singly, for 30 min) and possible mechanisms of this compound participation in the formation of the structure of the neuroactive amino acid pool, biogenic amines and their metabolites in the hypothalamus (H), basal ganglia (BG) and cerebellum (C) of the brain of male rats weighing 160-280 g. The concentrations of amino acids as OPA derivatives were determined by reverse-phase HPLC and the content of biogenic amines and their metabolites--by ion-pair HPLC-ECD. The Tau load was followed by an elevation of the concentrations of glutamate, aspartate and their amides, GABA and tyrosine concentrations in cerebellum whereas in basal ganglia that of tyrosine and dopamine. The tryptophan, beta-alanine, dioxyphenylacetic acid, dopamine and norepinephrine levels were diminished in hypothalamus. The metabolic and functional relationships governing the imbalance of the neuroactive amino acid and biogenic amine pool in the neuroactive amino acid and biogenic amine pool in the CNS occurring after the Tau administration in vivo are interpreted using statistical analysis.

[The amino acid pool of the liver during activation of glutathione synthesis]. / Aminokislotnyi fond pecheni na fone aktivatsii sinteza glutationa.

Regularities of formation of a pool of free amino acids and their derivatives in the liver of rats were studied during L-2-oxothiazoidin-4-carboxylate-induced glutathione synthesis activation. It was shown that an increase in concentrations of sulfur-containing (cysteate, cysteine) and branched-chain (valine, isoleucine, leucine) amino acids was the most typical change. The correlation and linear-discriminant analysis of the whole range of the compounds studied in the dynamics of the experimental process has proved high informativeness of glycogenic amino acid levels, activation of the whole chain of synthesis and degradation of thiol-containing amino acids as well as determination of the obtained shifts in concentrations of reduced glutathione.

[The free amino acid content of the blood serum in bladder cancer patients]. / Soderzhanie svobodnykh aminokislot v syvorotke krovi bol'nykh rakom mochevogo puzyria.

The content of 18 amino acids in the blood serum was studied in 57 patients with T2-4 carcinoma of the bladder according to the stage of the process and the functional condition of the kidneys. Dysaminoacidemia was found in patients with T2 bladder carcinoma, which did not need correction; marked hypoaminoacidemia was encountered in stage T3-4 tumors. Chronic renal insufficiency (intermittent and terminal stages) is conductive to significant decrease of the blood amino acid level. The content of amino acids is lower in the postoperative than in the preoperative period. The degree of reduction of the amino acid content in blood was found to be dependent on the volume of the operation. The reduction of the amino acid content is more intense after cystectomy than after resection of the bladder. Correction of the blood amino acid content in the preoperative period in patients with T3-4 carcinoma of the bladder reduces the incidence of postoperative complications. Correction of hypoaminoacidemia with polyamine proves effective in patients with maintained renal nitrogen excreting function. In development of azotemia in patients with bladder carcinoma, substitution transfusion therapy for correction of hypoaminoacidemia becomes effective only after restoration of the nitrogen excreting function of the kidneys.

[Changes in protein metabolism and the free amino acid profile in bladder cancer]. / Izmeneniia belkovogo obmena i fond svobodnykh aminokislot pri rake mochevogo puzyria.

Protein metabolism status was assessed by standard procedures versus tumor stage and nitrogen-excreting function of the kidneys in 250 cases of urinary bladder cancer. In addition, 18 amino acids in the blood were assayed in 63 patients. Standard methods of examination identified protein metabolism disturbances in patients with stage III-IV renal failure whereas amino acid profile showed changes at a much earlier stage. Patients with T3-4 tumors revealed decreased blood amino acid levels. Renal failure and surgical trauma caused the level of most amino acids checked to decrease. The need for correction of the amino acid profile of the blood before and after surgery is discussed.