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PubMed1983

[Changes in the parameters of equilibrium binding of acidic dyes by contractile proteins during their functional activity and heat denaturation].

A study was made of the equilibrium distribution of acidic dyes (Heliogen blue, Bromthymol blue, Bromphenol blue, Phenol red) between actomyosin threads (intact, contracted by ATP, or denaturated by heating) and the medium. The limits of dye sorption (A infinity) were shown to rise with the increase in their hydrophobia. The heat denaturation is accompanied with similar changes in all the dyes examined: i.e. with the increase in the limits of dye sorption and constant dissociation, and with the decrease in dye affinity to protein. The functional activity of contractile proteins acted upon with ATP is accompanied with different changes. For Heliogen blue these are like those during denaturation, whereas for Phenol red these are quite opposite: the limits of dye sorption and constant dissociation diminish, and the affinity to protein rises. Thus, during the heat denaturation the number of polar and non-polar groups accessible to dyes increases, whereas during functional activity only the number of non-polar bonds increases, and the quantity of polar bonds is seen reduced.

Absorption↗
PubMed1978

[Method of counterstaining preparations for immunofluorescent studies of the pituitary].

To elucidate nonfluorescent structural elements of the hypophyseal parenchyma for immunofluorescent investigations, properties of some dyes most commonly applied for hypophysis staining have been studied. Such dyes as paraldehide-fuchsin, light green, orange G, chromotrop 2R, hematoxylin, eosin, fuchsin, azocarmin possess their own intensive luminescence and block immunofluorescence completely. Some other dyes (trypan blue, bromthymol blue, aniline blue, malachite green, methyl green) though not blocking immunofluorescence, they do not reveal hypophyseal cellular elements distinctly enough. Good results have been obtained with 0.3% water solution of toluidine blue, 0.5% solution of methylene light blue, methylene blue, as well as with Gram--Weigert's staining and with gallocyanin after Einarson. For special staining of corticotropocytes, the authors recommend 0.1% solution of bromphenol blue in barate buffer, pH 8.2.

Adrenocorticotropic Hormone↗
PubMed1974

Relationship of a proton gradient to the active transport of proline with membrane vesicles from Mycobacterium phlei.

Electron transport particles prepared from Mycobacterium phlei were depleted of bound coupling factors by washing with water in the absence of inorganic ions. The depleted electron transport particles were void of latent ATPase activity and were capable of oxidation, but were unable to support coupled phosphorylation. Nevertheless, the depleted electron transport particles were capable of substrate-induced active transport of proline. Changes in pH in response to substrate oxidation were measured in normal and depleted electron particles with bromthymol blue. A bromthymol blue response upon substrate oxidation was not observed with depleted electron transport particles. The level of oxidative phosphorylation with succinate or NADH oxidation was not reduced in the presence of proline, and proline did not have an effect upon the proton gradients formed by the oxidation of either succinate or NADH.

Adenosine Triphosphatases↗
PubMed1977

Enhancement of pulmonary drug absorption in the rat by bromphenol blue and related dyes.

1. Pulmonary absorption studies in the rat showed that intratracheally administered 5-10 mM bromphenol blue, bromcresol green and bromthymol blue markedly increased the absorption rate of 0.1 mM phenol red. 2. Similarly, 1-10 mM bromphenol blue increased the absorption rate of 0.1 mP p-,minohippuric acid, tetraethylammonium and mannitol by 2- to 18-fold in a concentration-dependnet manner. 3. Mannitol absorption was enhanced more by bromthymol blue, sulphobromophthalein, bromcresol purple, thymol blue and bromcresol green than by bromphenol blue or m-cresol purple. Chlorphenol red and phenol red had no effect on mannitol absorption. 4. The results indicated that certain sulphonic acid dyes increase the permeability of the respiratory tract epithelium, perhaps by increasing its porosity.

Aminohippuric Acids↗
PubMed1981

Factors affecting the efflux of paraquat from rat lung slices.

In an attempt to reduce the toxicity of paraquat several compounds were examined for their ability to increase the rate of efflux of paraquat from the lung. The compounds were selected because they were known, from in vitro studies, to reduce the accumulation of paraquat into the lung. Histamine (100 MicroM), promethazine (100 microM), putrescine (100 microM), bromthymol blue (300 microM) and the metabolic inhibitors iodoacetate (1 mM), rotenone (100 microM) and KCN (1 mM) have been shown to reduce the accumulation of paraquat into rat lung slices, as did the incubation of slices under nitrogen. The efflux of paraquat from lung slices prepared from rats dosed intravenously with paraquat was biphasic, having a very fast component and a slow component. The slow component was first order and was characterised by a t1/2 of 17 h. This half life is similar to that seen in vivo (24 h) following intravenous dosing. When lung slices prepared from rats dosed intravenously with paraquat were incubated in the presence of iodoacetate (1 mM) or under nitrogen, the half life of paraquat in the slices was reduced to approximately 3 h. In the presence of rotenone (100 microM) it was reduced to approximately 9 h. Histamine (100 microM) and promethazine (100 microM) did not affect the efflux of paraquat from lung slices. Bromthymol blue, a dye which forms "ion pair" complexes with paraquat, also significantly increased the efflux of paraquat from lung slices. The effect of bromthymol blue, however, decreased with time and thus paraquat efflux in the presence of bromthymol blue did not obey first order kinetics. In order to measure cellular viability of lung slices, oxygen consumption, glucose oxidation and the rate of the efflux of protein from the slices into the incubation medium were determined. Iodoacetate (1 mM) and rotenone (100 mM) almost abolished oxygen consumption and glucose oxidation whereas these activities were inhibited to a lesser extent by bromthymol blue (300 microM) (18% and 30%, respectively). During the first 30 min of incubation in the presence of KCN (1 mM) oxygen consumption was almost abolished but between 30 min and 4 h returned to control levels. The effect of KCN could therefore be divided into 2 phases. Over 4 h incubation glucose oxidation was inhibited by 36%. Iodoacetate (1 mM) and incubation under nitrogen caused the most pronounced increases in the rate of protein efflux from slices. KCN (1 mM) and rotenone (100 microM) also increased the rate of protein efflux but to a lesser extent. We have therefore suggested that the effect of KCN (1 mM) on cellular viability, while severe, may be less than that of iodoacetate (1 mM) or incubation under nitrogen...

Animals↗
PubMed2006

Experiences with carrier-mediated transport in liquid-phase microextraction.

Different organic borates, phosphates, sulphates, and carboxylic acids are evaluated as extraction carriers in three-phase liquid-phase microextraction (LPME). Hydrophilic basic drugs form ion-pairs with the carriers and are extracted as ion-pair complexes into an organic liquid membrane of n-octanol or peppermint oil immobilized in the pores of a polypropylene hollow fiber. From this point, the basic drugs are released into a 20-microL solution of 50mM HCl placed inside the lumen of the hollow fiber (acceptor solution). Simultaneously, the carrier is neutralized by protons from the acceptor solution (protonated to maintain the charge balance). Both water-soluble and water-insoluble carriers are tested. One promising candidate among the water-soluble carriers is 1-heptanesulfonic acid. This is added to the sample solution to a final concentration of 25mM and served to ion-pair the analytes within the sample solution. Among the less water-soluble candidates, a mixture of di(2-ethylhexyl) phosphate (DEHP) and tris(2-ethylhexyl) phosphate (TEHP) serve as efficient carriers. Ten percent (w/w) of each of DEHP and TEHP are added to the organic liquid membrane, and these carriers principally worked through ion-pairing with the analytes at the interface between the sample solution and the organic liquid membrane. Several carriers are found to be compatible with human plasma samples, and bromthymol blue is particularly efficient in combination with these protein-containing matrices. Following optimization of the conditions for bromthymol blue, including saturation of the plasma samples with sodium sulphate, extraction recoveries between 45% and 75% are obtained for eight model drugs after 60 min of extraction. With bromthymol blue as the carrier, highly acceptable validation data are obtained for phenylpropanolamine and practolol extracted from human plasma.

Anions↗
PubMedDate not supplied

[Estimation of intact outer and inner membranes of heart mitochondria].

A simple procedure is developed for estimation of the damage rate of inner membrane of heart mitochondria. In the assay the rate of succinate oxidation was measured using bromthymol blue as an inhibitor of succinate transport. Bromthymol blue at low concentration (12 microM) functioned as a mixed type inhibitor of succinate oxidation, whereas at high concentrations--as uncompetitive inhibitor. Polarographic registration of cytochrome c content and of the rate of ascorbate oxidation in the samples containing Triton X-100 and free of the detergent was more sensitive procedure as compared with spectrophotometric measurement of reduced cytochrome c oxidation in estimation of the damage rate of outer mitochondrial membranes. The damage rates of outer and inner membranes of heart mitochondria isolated by a procedure which included the treatment with trypsin were equal to 8.43 +/- 0.74% and 8.04 +/- 1.9%, respectively, while in those isolated without the trypsin treatment--12.8 +/- 1.5% and 13.3 +/- 1.8%, respectively.

Animals↗
PubMed1990

Tracking of proton flow during transition from anaerobiosis to steady state in rat liver mitochondria.

(1) The hydrophobic pH indicator Bromthymol blue and the hydrophilic pH indicator Phenol red have been used to follow the redox-pump-linked proton flows during transition from anaerobiosis to static head. The domains monitored by the pH indicators, whether external or internal, and the localization of the dye, whether free or membrane bound, have been identified by recording the absorbance changes following addition of nigericin or valinomycin to anaerobic or aerobic mitochondria and the effects of permeant and impermeant buffers. (2) After addition of the H+/K+ exchanger, nigericin, to anaerobic mitochondria. Phenol red and Bromthymol blue record an alkalinization and an acidification, respectively, indicating that while the hydrophilic pH indicator faces an external domain, the hydrophobic pH indicator faces, at least partly, an internal domain. The latter effect is sensitive to phosphate and to phosphate carrier inhibitors. On the other hand, addition of nigericin to aerobic mitochondria leads to an increased Bromthymol blue absorbance, which reflects an alkalinization, indicating that the pH indicator faces an external domain. The reorientation of the dye from the internal to the external domain is a function of the uncoupler concentration and thus of the membrane potential (cf. Mitchell et al. (1968) Eur. J. Biochem. 4, 9-19). (3) The amount of oxygen required for the transition from anaerobiosis to static head has been determined by following in parallel the extent of oxidation of cytochrome aa3 and the rise of delta mu H+. With succinate as substrate, 50% levels of cytochrome oxidation are obtained at 0.125 ngatom oxygen/mg and 50% of Safranine response at about 0.2 ngatom oxygen/mg. These amounts of oxygen correspond to an H+ displacement of about 0.8-1.2 ngatom/mg on the basis of the H+/O stoichiometry. It is concluded that mitochondria are in presteady state below, and in static head above, displacement of 2-3 ngatom H+/mg. This figure is very close to the original calculation of Mitchell (Mitchell, P. (1966) Biol. Rev. 41, 445-502). (4) Transition, by oxygen pulses, of EGTA-supplemented mitochondria from anaerobiosis to either presteady state or static head state results in a response of the hydrophilic pH indicator, Phenol red, which is negligible in amount and/or kinetically unrelated to the delta mu H+ rise. The fact that H+ extrusion in the bulk aqueous phase is negligible also in presteady state excludes proton cycling as an explanation. Addition of oxygen pulses to Sr2(+)-supplemented anaerobic mitochondria results in an H+ extrusion whose amount and rate is proportional to the Sr2+ concentration.(ABSTRACT TRUNCATED AT 400 WORDS)

Anaerobiosis↗
PubMed1982

Improved diagnostic medium for separation of Cryptococcus neoformans var. neoformans (serotypes A and D) and Cryptococcus neoformans var. gattii (serotypes B and C).

A simple new agar medium containing L-canavanine, glycine, and bromthymol blue was found to give a clearer and more accurate distinction between serotype A or D (Cryptococcus neoformans var. neoformans) and serotype B or C (C. neoformans var. gattii) than creatinine-dextrose-bromthymol blue or glycine-cycloheximide-phenol red media. Among 143 isolates of serotype A or D and 70 isolates of serotype B or C, the new medium correlated completely with the serotype, whereas nearly 11% of these isolates gave discrepant reactions with creatinine-dextrose-bromthymol blue and glycine-cycloheximide-phenol red media.

Cryptococcus↗
PubMed1979

[Study of bromthymol blue-prealbumin in the blood serum of rats under hyperbaric oxygenation].

Three-fold increase of BTB-prealbumin (Rm 1.0) in rat serum following fierse convulsions under hyperbaric oxygenation (6 ati, 30-35 min) has been proved by disc electrophoresis. Glial S100-protein and 7-fold increase in the all-organ component of brain BTB-prealbumin were found by immunochemistry to appear in the serum of experimental rats. The consequences of disorders in the blood-brain barrier for non-specific, all-organ proteins and potentialities of protein output from the brain into the blood similarly to neurophysins under hyperbaric oxygenation are discussed.

Animals↗
PubMed1985

An oxygenation-linked dye binding to Limulus polyphemus hemocyanin.

The reaction of Limulus polyphemus hemocyanin with a dye, bromthymol blue, was examined by equilibrium dialysis, spectrophotometric titration and stopped-flow methods. Oxy-hemocyanin contained one binding site per hexamer unit. The dye binding was linked to oxygenation, and the affinity of the dye for the oxy form was about 10 times as high as that for the deoxy form. Conversely, the dye increased the O2 affinity of hemocyanin. Hemocyanin showed a simple hyperbolic binding curve in the bromthymol blue titration, whereas the time course of the reaction was generally biphasic. It was inferred from the kinetic analyses that the reaction proceeds in two steps. The first bimolecular step is characterized by an increase in the apparent pKa of the bound dye, while the second unimolecular step by a red shift of the absorption band of the unionized dye. The dye binding to partially oxygenated hemocyanin was examined spectrophotometrically; the fractional change in the binding was found to be ahead of the increase in the average degree of O2 saturation. It was concluded that the structural changes in hemocyanin which lead to the increased dye affinity take place at an early stage of the ligand binding sequence.

Animals↗
PubMed1976

Simple and rapid determination of a new pharmaceutically active amine hydrochloride.

The quantitative analysis of a new pharmaceutically active amine hydrochloride is described. Samples are extracted with chloroform. A yellow amine-dye complex is formed by buffering a sample-bromthymol blue solution at pH 8.5 +/- 0.1 and subsequently extracted with chloroform. The complex is treated with 0.01 N NaOH to convert it back to the sodium salt of bromthymol blue, which is then measured at 615 nm in the aqueous layer. The amount of complex extracted is linearly related to the amount of amine present, from 0.020 to 0.20 mg/ml. Under the selected conditions, the compound can be determined in the presence of degradation products and there is no interference from common pharmaceutical excipients. The method is suitable for stability studies.

Benzopyrans↗
PubMed1985

[Evaluation of structuro-functional heterogeneity of isolated mitochondria from the normal and the ischemic myocardium].

The structural and functional heterogeneity of mitochondria isolated from intact and ischemic (after 60 min exposure at 37 degrees C) rabbit myocardium was evaluated. In the presence of cytochrome c. a relatively high (260 +/- 26 ng at O/min . mg of protein) rate of rotenone-sensitive NADH oxidation was observed, which was increased in ischemia. Cytochrome c stimulated the increase of NADH oxidation in mitochondria of normal and ischemic myocardium by the factors of 3.5 and 3.4, respectively. Succinate oxidation in the presence of bromthymol blue in normal and ischemic myocardium mitochondria was activated by cytochrome c 3.3- and 2.9-fold, respectively. The percentage of mitochondria with both structurally damaged membranes was 15% and 25% in normal and ischemic myocardium preparations, respectively. In the absence of ADP, cytochrome c contributed to the increase of the succinate oxidase activity in ischemic mitochondria; that in the 3rd state was inhibited in ischemia and normalized by cytochrome c. A principle was proposed for estimating the percentage of mitochondria with damaged outer membranes, the indices being equal to 34% in control and to 56% in ischemic myocardium. Evidence was obtained suggesting that this mitochondrial fraction was characterized by lowered coupling and absence of rotenone-sensitive NADH: oxidase activity. The percentage of intact mitochondria, in which succinate oxidation is inhibited by bromthymol blue and does not need exogenous cytochrome c, is 51% in control and 19% in ischemic myocardium mitochondria.

Animals↗
PubMed1969

The inhibitory effect of convulsant agents on the enzyme in brain which inactivates nerveside.

1. An enzyme which can be extracted from brain inactivates nerveside in the optimum pH range 5.8-7.0.2. The polybasic acids trypan blue and its analogue trypan red, bromphenol blue and its analogue bromthymol blue at concentrations of 0.22 mM and ethylenediaminetetra-acetic acid (EDTA) at a concentration of 1 mM are strong inhibitors of the enzyme.3. Penicillin which is a monobasic carboxylic acid also inhibits the enzyme but only if concentrations as high as 3.6 mM are used. The antibiotic streptomycin which is a basic substance does not inhibit the enzyme.4. Caffeine at a concentration of 7.2 mM only weakly inhibits the enzyme.5. Chymotrypsin and wheat germ acid phosphatase also inactivate nerveside at pH 5.9 and are inhibited by the acidic dyes and penicillin. EDTA inhibits wheat germ phosphatase but activates chymotrypsin.6. Inactivation of nerveside by the brain enzyme and by wheat germ phosphatase is different from the action of chymotrypsin. Nerveside solutions incubated with chymotrypsin completely lose all biological activity whereas if incubation is carried out with either the brain enzyme or wheat germ acid phosphatase a residual biological activity remains even when the concentration of these two enzymes is increased. This residual biological activity is due to a peptide as it is destroyed by chymotrypsin.7. The manner in which nerveside is inactivated by the brain enzyme is uncertain as the preparation of the latter contained phosphodiesterase and protease activities which were similarly inhibited by the acid dyes, penicillin and EDTA.8. Pentylenetetrazole, picrotoxin, strychnine and tetanus toxin do not inhibit the brain enzyme.9. The nerveside-inactivating enzyme is not identical with the Substance P-inactivating enzyme in brain as the former is inhibited by EDTA while the latter is not.

Acid Phosphatase↗