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1.
Summary. Recent literature suggests that both caffeine and taurine can induce diuresis and natriuresis in rat and man. Although they
act via different cellular mechanisms, their diuretic actions might be additive. This is of considerable interest, as several
commercially available energy drinks contain both substances.
In this study we examined the possible diuretic effects of caffeine and taurine in a cross-over-design in which 12 healthy
male volunteers received each of 4 different test drinks (750 ml of energy drink containing 240 mg caffeine and 3 g taurine,
the three other test drinks either lacked caffeine, taurine or both) after restraining from fluids for 12 h.
Mixed model analyses demonstrated that urinary output and natriuresis were significantly increased by caffeine (mean differences
243 ml and 27 mmol; both p < 0.001) and that there were no such effects of taurine (mean differences 59 ml and −4 mmol). Additionally, urinary osmolarity
at baseline was significantly related to the urinary output (p < 0.001). Urine osmolarity values at baseline and in the 6 h urine collection did not differ significantly between treatments.
Taken together, our study demonstrates that diuretic and natriuretic effects of the tested energy drink were largely mediated
by caffeine. Taurine played no significant role in the fluid balance in moderately dehydrated healthy young consumers. Consequently,
the diuretic potential of energy drinks will not differ significantly from other caffeine containing beverages. 相似文献
2.
Relationship of taurine and other amino acids in plasma and in neutrophils of septic trauma patients
Engel JM Mühling J Weiss S Kärcher B Löhr T Menges T Little S Hempelmann G 《Amino acids》2006,30(1):87-94
Summary. Recently, an interdependency of plasma taurine and other amino acids as well as metabolic and clinical variables implicating
therapeutic options was reported. This result may be an indication that plasma taurine levels are directly related to intracellular
levels. Therefore, the aim of this study was to analyse the possible relationship between taurine levels in plasma and in
neutrophils, the relationship to other amino acids, and variables quantifying metabolic impairment and severity of sepsis
in multiple trauma patients developing sepsis. After multiple trauma taurine decreased significantly in plasma in thirty-two
patients as well as within the neutrophil and does not recover in sepsis. Lower individual levels in the neutrophil did not
follow lower individual levels in plasma and no correlation of taurine in plasma and in the neutrophils could be observed.
In sepsis, only plasma showed an interdependency of taurine, aspartate, and glutamate. No association between taurine plasma
or intracellular levels and SOFA score as indicator for severity of sepsis or metabolic variables was observed. After multiple
trauma and in sepsis, taurine uptake in cells (which is regulated in different ways), and intracellular taurine (which serves
e.g. as an osmolyte) can be influenced. Therefore a prediction of the neutrophil taurine pool seems not fully possible from
taurine plasma levels. Intracellular taurine has some unique properties explaining the missing interdependency despite some
similarities in osmoregulation and metabolic interactions to other amino acids. The association of taurine, aspartate, and
glutamate in plasma cannot be simply transferred to the neutrophils intracellular level. The clinical meaning of the plasma
correlation remains unclear. A dependency of plasma and neutrophil taurine to severity of sepsis and to metabolic variables
seems not possible because of the multifactorial pathophysiology of sepsis. 相似文献
3.
Near infrared spectroscopy, cluster and multivariate analysis hyphenated to thin layer chromatography for the analysis of amino acids 总被引:1,自引:0,他引:1
Summary. A method based on near-infrared spectroscopy (NIRS) was developed for the rapid and non-destructive determination and quantification
of solid and dissolved amino acids. The statistical results obtained after optimisation of measurement conditions were evaluated
on the basis of statistical parameters, Q-value (quality of calibrations), R2, standard error of estimation (SEE), standard error of prediction (SEP), BIAS applying cluster and different multivariate
analytical procedures. Experimental optimisation comprised the selection of the highest suitable optical thin-layer (0.5,
1.0, 1.5, 2.0, 2.5, 3.0 mm), sample temperature (10–30 °C), measurement option (light fibre, 0.5 mm optical thin-layer; boiling
point tube; different types of cuvettes) and sample concentration in the range between 100 and 500 ppm. Applying the optimised
conditions and a 115-QS Suprasil? cuvette (V = 400 μl), the established qualitative model enabled to distinguish between different dissolved amino acids with
a Q-value of 0.9555. Solid amino acids were investigated in the transflectance mode, allowing to differentiate them with a
Q-value of 0.9155. For the qualitative and quantitative analysis of amino acids in complex matrices NIRS was established as
a detection system directly onto the plate after prior separation on cellulose based thin-layer chromatography (TLC) sheets
employing n-butanol, acetic acid and distilled water at a ratio of 8:4:2 (v/v/v) as an optimised mobile phase. Due to the
prior separation step, the established calibration curve was found to be more stable than the one calculated from the dissolved
amino acids. The found lower limit of detection was 0.01 mg/ml. Finally, this optimised TLC-NIRS method was successfully applied
for the qualitative and quantitative analysis of L-lysine in apple juice. NIRS is shown not only to offer a fast, non-destructive
detection tool but also to provide an easy-to-use alternative to more complicated detection methods such as mass spectrometry
(MS) for qualitative and quantitative TLC analysis of amino acids in crude samples. 相似文献
4.
Baran H 《Amino acids》2006,31(3):303-307
Summary. The aim of the study was to investigate the changes of taurine in the kainic acid (KA, 10 mg/kg, s.c.) chronic model of epilepsy,
six months after KA application. The KA-rats used were divided into a group of animals showing weak behavioural response to
KA (WDS, rare focal convulsion; rating scale <2 up to 3 h after KA injection) and a group of strong response to KA (WDS, seizures;
rating >3 up to 3 h after KA injection). The brain regions investigated were caudate nucleus, substantia nigra, septum, hippocampus,
amygdala/piriform cortex, and frontal, parietal, temporal and occipital cortices. KA-rats with rating <2 developed spontaneous
WDS which occurred chronically and six months after KA injection increased taurine levels were found in the hippocampus (125.4%
of control). KA-rats with rating >3 developed spontaneous recurrent seizures and six months after injection increased taurine
levels were found in the caudate nucleus (162.5% of control) and hippocampus (126.6% of control), while reduced taurine levels
were seen in the septum (78.2% of control). In summary, increased taurine levels in the hippocampus may involve processes
for membrane stabilisation, thus favouring recovery after neuronal hyperactivity. The increased taurine levels in the caudate
nucleus could be involved in the modulation of spontaneous recurrent seizure activity. 相似文献
5.
Summary. Taurine transport in human intestinal epithelial Caco-2 cells was down-regulated by culturing the cells in taurine-containing
media and was up-regulated in a taurine-free medium. This adaptive regulation was associated with changes in both the Vmax
and Km values of taurine transport. A change in the mRNA level of the taurine transporter (TAUT) in this regulation was also
observed. The presence of such a regulatory mechanism for maintaining the intracellular taurine content at a certain level
suggests that taurine plays an important role in the intestinal cell functions. The intracellular taurine content was increased
when Caco-2 cells were exposed to a hypertonic stress. TAUT was up-regulated via the increased expression of TAUT mRNA in
the hypertonic cells, suggesting that taurine serves as an osmolyte and protects the cells from osmotic stress. Similar up-regulation
of TAUT was observed in the small intestine of water-deprived rats.
Received January 25, 2000/Accepted January 31, 2000 相似文献
6.
Summary. This paper examines a unique hypothesis regarding an important role for taurine in renal development. Taurine-deficient neonatal
kittens show renal developmental abnormalities, one of several lines of support for this speculation. Adaptive regulation
of the taurine transporter gene is critical in mammalian species because maintenance of adequate tissue levels of taurine
is essential to the normal development of the retina and the central nervous system. Observations of the remarkable phenotypic
similarity that exists between children with deletion of bands p25-pter of chromosome 3 and taurine-deficient kits led us
to hypothesize that deletion of the renal taurine transporter gene (TauT) might contribute to some features of the 3p-syndrome.
Further, the renal taurine transporter gene is down-regulated by the tumor suppressor gene p53, and up-regulated by the Wilms
tumor (WT-1) and early growth response-1 (EGR-1) genes. It has been demonstrated using WT-1 gene knockout mice that WT-1 is
critical for normal renal development. In contrast, transgenic mice overexpressing the p53 gene have renal development defects,
including hypoplasia similar to that observed in the taurine-deficient kitten. This paper reviews evidence that altered expression
of the renal taurine transporter may result in reduced intracellular taurine content, which in turn may lead to abnormal cell
volume regulation, cell death and, ultimately, defective renal development.
Received January 25, 2000/Accepted January 31, 2000 相似文献
7.
Summary. The concentrations of free amino acids in plasma change coordinately and their profiles show distinctive features in various
physiological conditions; however, their behavior can not always be explained by the conventional flow-based metabolic pathway
network. In this study, we have revealed the interrelatedness of the plasma amino acids and inferred their network structure
with threshold-test analysis and multilevel-digraph analysis methods using the plasma samples of rats which are fed diet deficient
in single essential amino acid.
In the inferred network, we could draw some interesting interrelations between plasma amino acids as follows: 1) Lysine is
located at the top control level and has effects on almost all of the other plasma amino acids. 2) Threonine plays a role
in a hub in the network, which has direct links to the most number of other amino acids. 3) Threonine and methionine are interrelated
to each other and form a loop structure. 相似文献
8.
Summary. This study investigates the relationship between changes in plasma sodium and changes in amino acid levels in a patient with
post-traumatic sepsis and prolonged critical illness. Ninety-two consecutive measurements were performed at regular intervals
over a period of many weeks; these consisted in the determination of full amino-acidograms, plasma sodium and complementary
variables. A unique, highly significant inverse correlation between taurine and plasma sodium was found (r2 = 0.48, p < 0.001). All other amino acids were unrelated, or much more weakly related, to sodium. Taurine was also strongly
and directly related to phosphoethanolamine, glutamate and aspartate. Changes in sodium and in levels of these amino acids
explained up to 86% of the variability of taurine. Besides, levels of these amino acids maintained a high degree of co-variation,
remaining reciprocally related one to each other, directly, with r2 ranging between 0.33 and 0.59 (p < 0.001 for all). There were similar findings for β-alanine, which however was measured inconsistently. These data provide gross clinical evidence of a specific link binding
plasma sodium and taurine levels, and may be consistent with occurrence of opposite and interdependent shifts of sodium and
taurine between intravascular and extravascular space, to maintain osmoregulation. Co-variation of taurine with the other
amino acids may be related to the same phenomenon, and/or to similarities in transport systems and chemical structure, or
true metabolic interactions.
Received April 16, 2002 Accepted June 19, 2002 Published online November 14, 2002
RID="*"
ID="*" Presented at the 7th International Congress on Amino Acids and Proteins, Vienna (Austria), August 6–10, 2001.
Acknowledgements The authors acknowledge the kind assistance of Mr. Maurizio Cianfanelli, from the Catholic University School of Medicine,
Rome, Italy.
Authors' address: Dr. Carlo Chiarla, Via Augusto Tebaldi, 19, I-00168 Roma, Italy, E-mail: carlo.chiarla@rm.unicatt.it 相似文献
9.
Summary. In human, physiological taurine requirement is partly dependent on nutrition. Study of the human carcinoma LoVo cells shows
the presence of a high and a low affinity taurine uptake. Besides them, a diffusion system has been found. A detailed analysis
of the properties of the three systems is presented. A comparison of LoVo chemosensitive cells, and LoVo chemoresistant (MDR)
cells which overexpress the multidrug transporter P-glycoprotein, shows that the only difference between the two cell types
belong to the kinetic properties of the high and low affinity taurine uptake systems.
Received May 19, 1999/Accepted August 16, 1999 相似文献
10.
Summary. We studied in vivo production of taurine, hypotaurine and sulfate following subcutaneous administration of L-cysteinesulfinate (CSA) to rats and mice. When 5.0 mmol/kg of body weight of CSA was injected to rats, increased urinary
excretions of taurine, hypotaurine and sulfate in 24 h urine were 617, 52 and 1,767 μmol/kg, respectively. From these results
together with our previous data, sulfate production was calculated to be 1.6 times greater than taurine production. Increased
contents (μmol/g of wet tissue) over the control of taurine and hypotaurine in mouse tissues at 60 min after the injection
of 5.0 mmol/kg body weight of CSA were: liver, 3.5 and 9.9; kidney, 0.3 and 5.2; heart, 3.7 and 0.2; blood plasma, 0.4 and
0.2, respectively. Upon loading of hypotaurine or taurine, tissue contents of these amino acids in liver and kidney increased
greatly. Our results indicate that liver is the most active tissue for taurine production, followed by kidney, and that external
CSA, hypotaurine and taurine are easily taken up by these tissues. 相似文献
11.
Role of osmoregulation in the actions of taurine 总被引:7,自引:0,他引:7
Summary. Taurine regulates an unusual number of biological phenomena, including heart rhythm, contractile function, blood pressure,
platelet aggregation, neuronal excitability, body temperature, learning, motor behavior, food consumption, eye sight, sperm
motility, cell proliferation and viability, energy metabolism and bile acid synthesis. Many of these actions are associated
with alterations in either ion transport or protein phosphorylation. Although the effects on ion transport have been attributed
to changes in membrane structure, they could be equally affected by a change in the activity of the affected transporters.
Three common ways of altering transporter activity is enhanced expression, changes in the phosphorylation status of the protein
and cytoskeletal changes. Interestingly, all three events are altered by osmotic stress. Since taurine is a key organic osmolyte
in most cells, the possibility that the effects of taurine on ion transport could be related to its osmoregulatory activity
was considered. This was accomplished by comparing the effects of taurine, cell swelling and cell shrinkage on the activities
of key ion channels and ion transporters. The review also compares the phosphorylation cascades initiated by osmotic stress
with some of the phosphorylation events triggered by taurine depletion or treatment. The data reveal that certain actions
of taurine are probably caused by the activation of osmotic-linked signaling pathways. Nonetheless, some of the actions of
taurine are unique and appear to be correlated with its membrane modulating and phosphorylation regulating activities.
Received January 25, 2000/Accepted January 31, 2000 相似文献
12.
Summary. Sorbic acid has a system of conjugated double bonds which makes it able to undergo nucleophilic addition reactions with certain
functions. The interactions between sorbic acid and an amine present in the endogenous constituents of food were quantified.
We demonstrated the formation of new products and studied the underlying mechanisms using ethyl sorbate and various amines.
HPLC, GC, GC-SM and NMR analyses of the reaction mixes enabled the isolation and identification of the products. The addition
reactions led, at 20°C, to linear monoadducts and, at 50°C, to cyclic derivatives resulting from double addition. Mutagenesis
studies, involving Ames test and genotoxicity studies with HeLa cells and on plasmid DNA, in cyclic interaction products,
showed that none of the products studied presented neither mutagenic nor genotoxic activities.
Received September 28, 1999 相似文献
13.
Mühling J Nickolaus KA Halabi M Fuchs M Krüll M Engel J Wolff M Matejec R Langefeld TW Welters ID Menges T Dehne MG Sablotzki A Hempelmann G 《Amino acids》2005,29(3):289-300
Summary. The objective of this study was to determine the dose as well as duration of exposure-dependent effects of L-alanyl-L-glutamine,
arginine or taurine on polymorphonuclear neutrophil (PMN) free α-keto acid profiles and, in a parallel study, on PMN immune
functions. Exogenous L-alanyl-L-glutamine significantly increased PMN α-ketoglutarate, pyruvate PMN superoxide anion (O2−) generation, hydrogen peroxide (H2O2) formation and released myeloperoxidase (MPO) activity. Arginine also led to significant increases in α-ketoglutarate, pyruvate,
MPO release and H2O2 generation. Formation of O2− on the other hand was decreased by arginine. Incubation with taurine resulted in lower intracellular pyruvate and α-ketobutyrate
levels, decreased O2− and H2O2 formation and a concomitant significantly increased MPO activity. We therefore believe that considerable changes in PMN free-α-keto-acid
profiles, induced for example by L-alanyl-L-glutamine, arginine or taurine, may be one of the determinants in cell nutrition
that considerably modulates the immunological competence of PMN. 相似文献
14.
Summary. Calcium ion (Ca2+) uptake was measured in rod outer segments (ROS) isolated from rat retina in the presence of varying concentrations of CaCl2 in the incubation buffer (1.0–2.5 mM). It is known that taurine increases Ca2+ uptake in rat ROS in the presence of ATP and at low concentrations of CaCl2 (Lombardini, 1985a); taurine produces no significant effects when CaCl2 concentrations are increased to 1.0 and 2.5 mM. With the removal of both taurine and ATP, Ca2+ uptake in rat ROS increased significantly in the presence of 2.5 mM CaCl2. Taurine treatment in the absence of ATP was effective in decreasing Ca2+ uptake at the higher levels of CaCl2 (2.0 and 2.5 mM). Similar effects were observed with ATP treatment. The data suggest that taurine and ATP, alone or in combination,
limit the capacity of the rat ROS to take up Ca2+ to the extent that a stable uptake level is achieved under conditions of increasing extracellular Ca2+, indicating a protective role for both agents against calcium toxicity.
Received January 25, 2000/Accepted January 31, 2000 相似文献
15.
Protein-bound advanced glycation endproducts (AGEs) as bioactive amino acid derivatives in foods 总被引:2,自引:0,他引:2
Henle T 《Amino acids》2005,29(4):313-322
Summary. The Maillard reaction or nonenzymatic browning is of outstanding importance for the formation of flavour and colour of heated
foods. Corresponding reactions, also referred to as “glycation”, are known from biological systems, where the formation of
advanced glycation endproducts (AGEs) shall play an important pathophysiological role in diabetes and uremia. In this review,
pathways leading to the formation of individual protein-bound lysine and arginine derivatives in foods are described and nutritional
consequences resulting from this posttranslational modifications of food proteins are discussed. 相似文献
16.
Summary. Previously we have observed the lack of immunoreactivity of taurine in the rod outer segments from light-adapted fish, such
as the ayu Plecoglossus altivelis and lefteye flounder Paralichthys olivaceus. This finding prompted us to investigate if there is a difference in the immunocytochemical localization of taurine in the
rod outer segments between the dark- and light-adapted states. In the retinas of the glass eel Anguilla japonica and the young goldfish Carassius auratus, extremely intense immunostaining was found in the cone outer segments, rod inner segments, photoreceptor supranuclear region
and outer plexiform layer. The rod outer segments were not immunostained in the light-adapted state, while they were intensely
immunostained in the dark-adapted state. Consequently, it was suggested that the lack of immunoreactivity in the rod outer
segment may depend on light stimulation. In addition, the conspicuous immunocytochemical localization of taurine was discussed
with the possible functional roles for taurine in the fish retina.
Received January 25, 2000/Accepted January 31, 2000 相似文献
17.
Summary. Thermophilic proteins show substantially higher intrinsic thermal stability than their mesophilic counterparts. Amino acid
composition is believed to alter the intrinsic stability of proteins. Several investigations and mutagenesis experiment have
been carried out to understand the amino acid composition for the thermostability of proteins. This review presents some generalized
features of amino acid composition found in thermophilic proteins, including an increase in residue hydrophobicity, a decrease
in uncharged polar residues, an increase in charged residues, an increase in aromatic residues, certain amino acid coupling
patterns and amino acid preferences for thermophilic proteins. The differences of amino acids composition between thermophilic
and mesophilic proteins are related to some properties of amino acids. These features provide guidelines for engineering mesophilic
protein to thermophilic protein.
Authors’ addresses: Yuan-Jiang Pan, Institute of Chemical Biology and Pharmaceutical Chemistry, Zhejiang University, Zhejiang
University Road 38, Hangzhou 310027, China; Wei-Fen Li, Microbiology Division, College of Animal Science, Zhejiang University,
Hangzhou 310029, China 相似文献
18.
Summary. The interaction of amino acids with the herbicide 2,4-dichlorophenoxyacetic acid (2,4-D) was studied by charge-transfer chromatography
carried out on diatomaceous layers covered with different amount of 2,4-D and the effect of salts on the strength of interaction
was elucidated. It was established that Arg, His, Lys, Orn, Phe and Trp binds to 2,4-D, the binding process is of saturation
character. Principal component analysis proved that the concentration of 2,4-D exerts the highest impact on the interaction
and the effect of salts is of secondary importance. The results suggest that these amino acid residues may account for the
binding of 2,4-D to proteins and can play a considerable role in the detoxification processes by forming conjugates with 2,4-D.
Received April 10, 1998, Accepted September 15, 1998 相似文献
19.
Interaction between the actions of taurine and angiotensin II 总被引:1,自引:0,他引:1
Summary. The amino acid, taurine, is an important nutrient found in very high concentration in excitable tissue. Cellular depletion
of taurine has been linked to developmental defects, retinal damage, immundeficiency, impaired cellular growth and the development
of a cardiomyopathy. These findings have encouraged the use of taurine in infant formula, nutritional supplements and energy
promoting drinks. Nonetheless, the use of taurine as a drug to treat specific diseases has been limited. One disease that
responds favorably to taurine therapy is congestive heart failure. In this review, we discuss three mechanisms that might
underlie the beneficial effect of taurine in heart failure. First, taurine promotes natriuresis and diuresis, presumably through
its osmoregulatory activity in the kidney, its modulation of atrial natriuretic factor secretion and its putative regulation
of vasopressin release. However, it remains to be determined whether taurine treatment promotes salt and water excretion in
humans with heart failure. Second, taurine mediates a modest positive inotropic effect by regulating [Na+]i and Na+/Ca2+ exchanger flux. Although this effect of taurine has not been examined in human tissue, it is significant that it bypasses
the major calcium transport defects found in the failing human heart. Third, taurine attenuates the actions of angiotensin
II on Ca2+ transport, protein synthesis and angiotensin II signaling. Through this mechanism taurine would be expected to minimize many
of the adverse actions of angiotensin II, including the induction of cardiac hypertrophy, volume overload and myocardial remodeling.
Since the ACE inhibitors are the mainstay in the treatment of congestive heart failure, this action of taurine is probably
very important.
Received November 10, 1998, Accepted May 19, 1999 相似文献
20.
Effects of high salt diets and taurine on the development of hypertension in the stroke-prone spontaneously hypertensive rat 总被引:3,自引:0,他引:3
Summary. Taurine is present in high concentrations in mammalian tissues and has been implicated in cardiovascular control mechanisms.
The aim of the present study was to evaluate the ability of taurine to attenuate salt-induced elevations in blood pressure
and markers of damage to the kidney and cardiovascular system in stroke prone spontaneously hypertensive rats (SPSHR). Male
SPSHR (6 weeks old) were placed on high salt diets that contained 1% (w/w) NaCl added to their normal chow for 84 days and
then were switched to 3% added NaCl for the remaining 63 days of the study. SPSHR was given 1.5% taurine in the drinking water
(n = 8), a taurine free diet (n = 8) or normal chow (n = 8). A final control group (n = 6) was not given high salt diets.
High salt diets caused an acceleration in the development of hypertension in all groups. Taurine supplementation reduced ventricular
hypertrophy and decreased urinary excretion of protein and creatinine. The taurine free diet did not alter serum or urinary
excretion of taurine, but did result in elevated urinary nitrogen excretion, increased serum cholesterol levels, and impaired
performance in a spatial learning task. Alterations in dietary taurine intake did not alter urinary or serum electrolytes
(Na+, K+), but taurine supplementation did attenuate a rise in serum calcium seen with the high salt diets. Urinary excretion (μg/24
h) of epinephrine and dopamine was significantly reduced in SPSHR given 1% NaCl in the diet, but this effect was not seen
in SPSHR on taurine free or supplemented diets. Taurine supplementation showed cardioprotective and renoprotective effects
in SPSHR given high salt diets.
Received April 12, 1999/Accepted September 13, 1999 相似文献