Janusz Konecki

Free amino acids in bee hive product (propolis) as identified and quantified by gas-liquid chromatography

Propolis is a natural resinous product collected by honey bees and containing, among other biochemical constituents, a variety of free amino acids. Acid extraction and quantification of these amino acids by gas-liquid chromatography reveals that their total concentration in this honey bee product is over 40% w/w, and that arginine and proline constitutes over 50% of the crude acid extract. As propolis was shown to stimulate mammalian tissue regeneration, we suggest that the physiological significance of arginine in the propolis product lies in its ability to stimulate mitosis and to enhance protein biosynthesis, and that the biochemical importance of proline in it, stems from its capability to promote build-up of collagen and elastin, two essential components in the matrix of connective tissues.

Proteinous Amino Acids in Muscle Cytosol of Rats' Heart After Exercise and Hypoxia

Levels of 19 proteinous amino acids and of total free amino acids were assayed by gas-liquid chromatography in cytosols of rat atrial and ventricular heart muscle cardiomyocytes. These amino acids were assayed after the rats had been exposed to either exercise (swimming) or hypoxia (hypobaric pressure of 686 hectoPascals). Out of the total free amino acids levels of arginine, glutamine and cysteine in atrial and ventricular cardiac muscle cytosols of control rats were the highest of all amino acids assayed. The control levels of all other amino acids assayed in atrial or ventricular cardiac muscles ranged from 0.1% to 10.6% of the total free amino acids in the control rats. Physical stress (exercise and hypoxia) significantly reduced the total amount of cytosolic free amino acids in both heart muscles. While hypoxia decreased the levels of arginine in both heart muscles, exercise abolished the level of cysteine in the atrial heart muscle. Decrease in arginine levels, and elimination of cysteine from the hearts atrial muscle after physical stress, may be attributed to its utilization of nitric oxide and to its synthesis of atriopeptin and/or endothelin during stress. No change was recorded in either experimental group in the level of glutamine in heart muscle cytosol. Exercise and hypoxia affect, in different modes, the levels of all other amino acids assayed, except for tryptophan, tyrosine, and histidine, which are precursors of endogenous neurotransmitters. The impact of proteinous amino acids on some bodily functions is discussed.

Gas-liquid chromatography of free amino acids in the hyaloplasm of rat liver and kidney cells

Abstract Gas-liquid chromatography of free protein amino acids has a high and verified reproducibility of quantitative and qualitative estimation: Cytoplasmic matrix obtained from the 105,000g supernatant fraction of rat liver and kidney cells was investigated. The ultracentrifuged product was passed through ion-exchange resin, thus isolating free amino acids from the eluate. After lyophilization the product was derivatized to N-trifluoroacetyl n-butyl esters and separated on the OV 17 + 210 and ethylene glycol adipate phases. Flame ionization detection was used. Comparison of liver and kidney tissues showed significant differences in the concentrations of the amino acids studied.

Incorporation of [3H]uridine and [3H]glycine in the brain of rats prenatally exposure to cadmium

Numerous studies have demonstrated that exposure of mammalians, including humans to inorganic cadmium, result in a cascade of toxic effects. The developing mammalian brain is particularly more sensitive to cadmium then the adult brain, being affected both morphologically and neurochemically. Uridine is a precursor of RNA, and the intensity of its incorporation in tissue represents the rate of RNA and protein synthesis. Glicine is an important aminoacid, an element of many proteins and enzymes in mammalian organism. On the first day of pregnancy, Wistar rats were divided into two groups. First, control consumed filtred tap water while other half consumed filtred tap water with 50 ppm cadmium (CdCH3COO2). At eight weeks after birth both groups were injected with [3H]uridine (incorporated to RNA) or [3H]glycine (incorporated to protein) 1 μCi/kg IP. Four hours later rats were sacrificed by decapitation and parts of the brain were excised and examined for radioactivity in liquid scintillation counter. Results were presented as a disintegration per minute (DPM)/100 mg wet tissue weight, which expressed labeled substances incorporation. Prenatal exposure with cadmium significantly decreased [3H]uridine incorporation in all examined parts of the brain (frontal cortex, striatum, thalamus with hypothalamus, pons, hippocampus, cerebellum). Neonatal exposure rats to cadmium decreased incorporation of the [3H]glycine in frontal cortex, thalamus with hypothalamus, pons and cerebellum. From above we concluded and confirmed that prenatal exposure with cadmium exert a toxic effect on RNA and proteins synthesis in the brain of developing rats.

Free Amino Acids in Cytosol of Rat Brain after Intraventricular Administration of 5,6-Dihydroxytryptamine and 6-Hydroxydopamine

Abstract Levels of 24 free amino acids were estimated in the brain after administration of 5,6-dihydroxy-tryptamine and 6-hydroxydopamine into the lateral brain ventricles of male Wistar rats. These neurotransmitters caused serotoninectomy and sympathectomy in the diencephalon, striatum, brain stem and medulla, thalamus and hypothalamus, cerebral cortex and cerebellum. The most abundant amino acids in these brain structures were: glutamic acid, serine, aspartic acid, cystine, gamma-aminobutyric acid, glycine, tryptophan and alanine. We detected and quantified changes in the levels of these and other amino acids in the investigated regions of the rat central nervous system, under the influence of these two neurotransmitters.