bluuebunny/crossref_metadata_2025_split huggingface dataset:
The recovery of the capacity for uptake-retention of [3H]noradrenaline in rat adrenergic nerves after reserpine
Authors: HÄGGENDAL JAN , DAHLSTRÖM ANNICA 
Published: April 2011

Abstract
The uptake retention of [3H]noradrenaline (2.5 μg/kg, i.v., 30 min before death) in rat salivary glands was studied at different times after reserpine treatment (10 mg/kg, i.p.). The effect of removing the cervical superior ganglion 12 h before death on the recovery of the [3H]noradrenaline uptake-retention capacity after reserpine was also investigated. The ganglionectomy was unilateral, and the contralateral side was always preganglionically denervated. In glands with uninterrupted postganglionic adrenergic nerves the onset of recovery of the [3H]noradrenaline retention capacity occurred 24–36 h after reserpine. Normal contents were found on the second to third days. Between day 3 and 6 a possible overshoot of [3H]nor- adrenaline content, followed by normal and subnormal contents (7–21 days) were recorded. Ganglionectomy, 12 h before death, markedly delayed the recovery of [3H]noradrenaline retention capacity. Both the recovery curve for [3H]noradrenaline retention in glands with intact postganglionic nerves, and the effect of ganglionectomy on the [3H]noradrenaline retention capacity, were clearly related to the relative number of new functioning amine granules that are transported via the axons to the nerve terminals at different times after the reserpine-pretreatment. The results indicate that young amine granules, recently transported to the nerve terminals via the axons, have the greatest capacity to take up and retain [3H]noradrenaline. The half-life of this capacity in the young granules appears to be about 12 h. Since published results indicate that [3H]noradrenaline is initially taken up in the “small easily releasable pool” of transmitter, we suggest that young amine granules are of the greatest importance for adrenergic function, i.e. that they are particularly active in taking up recaptured noradrenaline, in the synthesis, and in the release of this transmitter.
Relations between particle shape, particle interaction and some rheological properties of hectorite dispersions
Authors: CARLESS J E , OCRAN J 
Published: April 2011

Abstract
The relation between viscosity and concentration of dilute aqueous hectorite (&lt;0·2% hectorite) follows the Schulz-Blaschke equation, from which the intrinsic viscosity and particle interaction index (K) was calculated. More concentrated (up to 5·5% hectorite) dispersions possessed plastic flow properties, and a modified Schulz-Blaschke equation was used to calculate an interaction factor (&#x004b;̄). A correlation was established of (&#x004b;̄) and the static yield of the gels assessed by a cone and plate viscometer. The static yield value of gels was increased by the addition of sodium chloride over the range 0·001–0·005m. In the presence of 0·01m uni-univalent electrolytes the gelling power of the cations was in the order NH4 &gt; K &gt; Na &gt; Li. A relation between sodium chloride concentration, hectorite concentration and static yield value of the gel was derived.
The composition of phytosterols in first and second year Digitalis purpurea L
Authors: EVANS F J 
Published: April 2011

Abstract
The phytosterols of Digitalis purpurea occur as lipids and as glucosides. Gas-liquid chromatography and mass-spectrometry indicated that both fractions contained sitosterol as the major component, and also varying proportions of stigmasterol, campesterol and cholesterol. Certain of the lipid fractions contained 24-methylenecholesterol. The phytosterol concentrations and relative proportions were determined at monthly intervals during the first year of growth, and also in various morphological units of second year plants. The composition of the phytosterol fractions depended upon the plant organ examined and also upon the phase of growth of the plant.
Haemodynamic and coronary effects of quazodine in cats with developing myocardial infarcts
Authors: PARRATT J R , WINSLOW EILEEN 
Published: April 2011

Abstract
Acute ligation of the descending branch of the left coronary artery in anaesthetized cats resulted, within 1–2 h, in a 30% decrease in local blood flow in the region mainly supplied by the ligated vessel, a fall in systemic blood pressure, in cardiac output, and in left ventricular dP/dt max (LVdP/dt). There was electrocardiographic evidence of myocardial ischaemia (pronounced ST elevation). In these animals with developing myocardial infarcts, intravenous infusions of quazodine (MJ1988; 6,7-dimethoxy-4-ethyl-quinazoline) markedly increased myocardial contractility and local myocardial blood flow in the developing infarct, and decreased systemic arterial pressure, peripheral vascular resistance and left ventricular end-diastolic pressure, effects similar to those observed in normal cats. The increase in cardiac contractility (cardiac output and LVdP/dt) occurred without a concomitant increase in myocardial metabolic heat production. This ‘oxygen sparing effect’ probably results from a decrease in left ventricular wall tension. It is suggested that quazodine warrants further investigation as a cardiac stimulant in power failure following myocardial infarction in man.
Effects of l-dopa and inhibitors of decarboxylase and monoamine oxidase on brain noradrenaline levels and blood pressure in spontaneously hypertensive rats
Authors: YAMORI YUKIO , DE JONG WYBREN , YAMABE HIROHIKO , LOVENBERG WALTER , SJOERDSMA ALBERT 
Published: April 2011

Abstract
Acute administration of l-dopa (200 mg/kg) resulted in a significant decrease in blood pressure of the spontaneously hypertensive (SH) rat. Simultaneous treatment with a peripheral decarboxylase inhibitor (3,4-dihydroxyphenyl-2-hydrazino-2-methylpropionic acid; MK 485) potentiated this effect while treatment with a decarboxylase inhibitor that penetrates the central nervous system (4-bromo-3-hydroxybenzyloxyamine; NSD 1055) tended to block the effect of l-dopa. In general, only treatments that increased brainstem noradrenaline were effective in reducing blood pressure. In young SH rats chronic treatment with l-dopa and a peripheral decarboxylase inhibitor significantly retarded the development of hypertension over four weeks. Treatment of SH rats with 3 daily doses (100 mg/kg each) of p-chlorophenylalanine resulted in a complete loss of 5-hydroxy-tryptamine and a slight reduction of noradrenaline in the brainstem. The blood pressure of these animals was slightly increased over that of the control SH rats. Treatment of several groups of SH rats with a monoamine oxidase inhibitor (pargyline) in various combinations with l-dopa and a peripheral decarboxylase inhibitor resulted in a wide range of noradrenaline levels in the brainstem. There appeared to be a highly significant inverse correlation between brainstem noradrenaline and blood pressure. The findings are consistent with central noradrenergic modulation of blood pressure in the rat.
The effect of pore size of the inhaler support upon the concentration of volatile drug emerging in the air stream from a nasal inhaler
Authors: Armstrong P A M , Carless J E , Enever R P 
Published: April 2011

Abstract
The effect that the pore size of the inhaler support has upon the concentration of methylamphetamine emerging in the airstream from a nasal inhaler has been investigated over a range of temperatures using a series of sintered glass plugs of differing porosity. The results showed that there was a reduction in the drug concentration with decrease in pore size of the plugs. An attempt was made to correlate these findings with the Kelvin equation. It was concluded that the degree of lowering of drug concentration was much greater than could be explained on the basis of this equation; and that this was due to the fact that the airstream was not saturated with the drug vapour. The degree of undersaturation appeared to be related to the porosity of the plugs.
Effect of inosine on guinea-pig bronchial muscle
Authors: Bertelli A , Bianchi C , Beani L 
Published: April 2011

Abstract
Inosine, like other purine derivatives, shows antibronchospastic effects both in vivo and in vitro. Its activity remains in propranololor α-methyl-p-tyrosine-pretreated guinea-pigs, but is prevented by theophylline. Moreover, the interaction between 3′5AMP and inosine suggests potentiation. In view of recent findings showing that inosine inhibits phosphodiesterases, the conclusion is drawn that the antibronchospastic effect of this nucleoside depends on the increase of 3′5′AMP intracellular levels in the bronchial muscle.
Application of orthogonal functions to correct for quadratic irrelevant absorption in spectrophotometric analysis
Authors: Wahbi A M , Abdine H 
Published: April 2011

Abstract
The seven-point correction method of Ashton and Tootill has been examined. The method is generalized for other groups of points from n = 5 to n = 14. Glenn's method of orthogonal functions proved to be suitable for assaying cyclandelate in the presence of interference with quadratic curvature.
Effect of ethanol on the hydroxylation of tyrosine and tryptophan in rat brain in vivo
Authors: Carlsson Arvid , Lindqvist Margit 
Published: April 2011

Abstract
Various doses of ethanol were injected intraperitoneally into rats. After 20 min, 3-hydroxybenzylhydrazine (NSD 1015), an inhibitor of aromatic amino-acid decarboxylase was injected and 30 min later the animals were killed. The amount of dopa accumulating in brain as a consequence of decarboxylase inhibition was significantly increased by moderate doses of ethanol (up to 4 g kg−1). There was no corresponding effect on 5-hydroxytryptophan. The effect on dopa was found both in a dopamine- and a noradrenaline-dominated area of the brain, suggesting that catecholamine synthesis is stimulated by ethanol in both types of neuron. The data lend support to the hypothesis of Carlsson, Engel & Svensson (1972) that cerebral catecholamines are involved in the central stimulation induced by ethanol.
Plasma half-lives, plasma metabolites and anticoagulant efficacies of the enantiomers of warfarin in man
Authors: Hewick David S , McEwen John 
Published: April 2011

Abstract
S-(-)-Warfarin was found to be a more potent anticoagulant than R-(+)-warfarin in man. However, S-warfarin was cleared more rapidly from the plasma; respective mean plasma half-lives (from four subjects) for R and S-warfarin were 45&#x006d;̇4 and 33&#x006d;̇0h. Unlike the assay of Lewis, Ilnicki & Carlstrom (1970), the assay of Corn & Berberich (1967) for measuring plasma warfarin gave spuriously long half-life values, particularly with R-warfarin. The apparent volumes of distribution of the enantiomers were not significantly different. A major plasma metabolite detected was warfarin alcohol1, which was seen in much greater quantities after giving R-warfarin than after S-warfarin. The corresponding diastereoisomer, warfarin alcohol2, was seen in trace amounts after S-warfarin only.
Kinetics of hydrolysis of polyoxyethylene (20) sorbitan fatty acid ester surfactants
Authors: Bates Theodore R , Nightingale Charles H , Dixon Edward 
Published: April 2011

Abstract
The kinetics of the hydrolysis of the oleate ester of polyoxyethylene (20) sorbitan (Tween 80) in aqueous buffers were studied at an initial concentration of 0&#x006d;̇020% (w/v) and over the pH range of 1&#x006d;̇10 to 10&#x006d;̇28. The hydrolysis appears to be specific acid-catalysed at pH values below 3 and specific base-catalysed at pH values greater than 7&#x006d;̇6. The pseudo first-order rate constants for hydrogen and hydroxyl ion catalysis were determined, and the temperature and ionic strength dependence of the acid-catalysed reaction was studied. Both the initial, acid- and base-catalysed hydrolysis of Tween 80 exhibited an unusual initial, micellar surfactant concentration-rate dependence, opposite to that previously reported for the hydrolysis of anionic surfactants of the n-alkyl sulphate-type. Specifically, as the initial concentration of Tween 80 was increased above its reported critical micellar concentration, there was a progressive, marked decrease in the rate of the reaction, with the rate eventually reaching a plateau value between 0&#x006d;̇100 and 1&#x006d;̇00% (w/v). It is suggested that this behaviour is due to alterations in the micellar state of the surfactant as its concentration is increased. The influence of the chemical structure of the Tween surfactant on the acid-catalysed hydrolysis reaction at 80° was also examined using the oléate (Tween 80), stéarate (Tween 60), and palmitate (Tween 40) esters of polyoxyethylene (20) sorbitan.
The reflection of ejecting and retaining currents in the time-course of neuronal responses to microelectrophoretically applied drugs
Authors: Bradshaw C M , Szabadi E , Roberts M H T 
Published: April 2011

Abstract
The role of ejecting and retaining currents in determining the time-course of neuronal responses to microelectrophoretically applied drugs (acetylcholine, glutamate, noradrenaline, 5-hydroxytryptamine, and mescaline) was investigated. Comparing the parameters of excitatory responses to ejecting currents of successively increasing intensity, the following changes were observed: the response latency became progressively shorter, the plateau became higher, and the recovery time was prolonged. An increase in the intensity or duration of the pre-ejection retaining current resulted in the prolongation of the response latency and the latency to plateau, but did not alter the plateau itself. An increase in the intensity of the post-ejection retaining current reduced the recovery time of the response.
Quantitation of Δ1-tetrahydrocannabinol in plasma from cannabis smokers
Authors: Agurell Stig , Gustafsson Bertil , Holmstedt Bo , Leander Kurt , Lindgren Jan-Erik , Nilsson Inger , Sandberg Finn , Asberg Marie 
Published: April 2011

Abstract
A method to identify and accurately measure non-labelled Δ1-tetrahydrocannabinol (Δ1-THC) in blood of cannabis smokers has been developed. It consists of the following steps: To a 5 ml plasma sample is added deuterated Δ1-THC (Δ1-THC-d2) as internal standard. After extraction with light petroleum and evaporation, the Δ1-THC containing fraction is separated by chromatography on Sephadex LH-20 (1 times 40 cm) using light petroleum-chloroform-ethanol (10:10:1) as eluant. A fraction containing Δ1-THC is collected and subjected to mass fragmentography (LKB 9000; 3% OV-17/Gas-Chrom Q; 230°). The mass spectrometer was adjusted to record the intensities of m/e 299 and 314 of Δ1-THC and m/e 301 and 316 of Δ1-THC-d2. The standard curve was made by plotting peak height m/e 299/m/e 301. Peak levels of 19–26 ng ml−1 were reached within 10 min after smoking a cigarette containing 10 mg Δ1-THC.
Differential effects of amphetamine, fenfluramine and norfenfluramine stereoisomers on the increase of striatum homovanillic acid in rats
Authors: Jori A , Dolfini E , Tognoni G , Garattini S 
Published: April 2011

Abstract
(+)-Amphetamine is more effective in increasing the concentration of striatum homovanillic acid (HVA) in rats than the (-)-isomer while the (-)-isomers of fenfluramine and norfenfluramine are more active than their (+)-isomers. The concentrations of the drugs in the striatum do not explain the difference observed between the isomers on striatum HVA. Fenfluramine does not appear to act on striatum HVA through the formation of norfenfluramine.
The effect of oral administration of various sugars on blood ethanol concentrations in man
Authors: Clark E R , Hughes I E , Letley E 
Published: April 2011

Abstract
Urine output and blood ethanol concentrations have been measured in volunteers for 2 h after the administration of a standard oral dose of ethanol (0.798 g kg−1) given 30 min after a large oral dose of one of several sugars in 200 ml water. Both fructose (125 g) and sorbitol (125 g) produced large reductions in urine output and blood-ethanol concentrations for the duration of the experiment when compared with controls. Galactose (125 g) had a similar but transient effect and smaller doses of fructose (62.5 g) were without these actions. It is concluded that the effects observed can be explained in terms of alterations in absorption of ethanol and water from the gastrointestinal tract.
Oscillatory testing of o/w emulsions containing mixed emulsifiers of the surfactant/long chain alcohol type: Influence of surfactant chain length
Authors: Barry B W , Eccleston G M 
Published: April 2011

Abstract
A Weissenberg Rheogoniometer with parallel plates coupled to a Solartron Digital Transfer Function Analyser was used at 25° in oscillatory mode to investigate liquid paraffin-in-water emulsions stabilized by alkyltrimethylammonium bromides (of C12-C18 chain lengths) and cetostearyl alcohol. Ternary systems, formed by dispersing the quaternary surfactants and cetostearyl alcohol in water, were similarly examined. Each preparation was tested in the linear viscoelastic region and fundamental rheological parameters, the storage modulus (G') and the dynamic viscosity (η′), were derived as functions of frequency over the range 7.91 × 10−4 to 25 Hz. The rheological properties of the emulsions were related to viscoelastic gel networks present in the continuous phases. The corresponding ternary system parameters implied that these networks were formed by the interaction of cetostearyl alcohol and aqueous surfactant solution. Ternary systems and emulsions behaved similarly with respect to frequency. As this increased, G' rose and η′ fell, the latter through several logarithmic decades. At low frequencies, G' and η′ rose as the quaternary alkyl chain length increased. Formulations containing quaternary surfactants of medium chain lengths (C14 and C16) formed strong viscoelastic networks. The C12 systems contained tenuous networks, and networks formed from the C18 surfactant were not as rigid as predicted by the trend of the lower homologues. The oscillatory data were compared and correlated with creep data described previously.
Biliary excretion kinetics of Phenolphthalein glucuronide after intravenous and retrograde biliary administration
Authors: Gustafson J H , Benet L Z 
Published: April 2011

Abstract
Several organic compounds of large molecular weight have previously been shown to be rapidly and primarily excreted via the biliary system of the rat after intravenous or retrograde biliary infusion. Poor biliary reabsorption has been suggested to explain these findings. The kinetics of the biliary excretion of Phenolphthalein glucuronide have been examined with concurrent plasma data. A spectrophotometric method, capable of measuring Phenolphthalein glucuronide in amounts as small as 4 nmol per 100 μl of plasma, was developed. The glucuronide (20–40 μmol kg−1) was administered to 14 rats intravenously and to 12 rats by retrograde biliary infusion. There was a significant concentration of Phenolphthalein glucuronide in the systemic blood after glucuronide administration by either route and the kinetics of elimination of the glucuronide were similar. The plasma availability of biliary infused doses was over 45 % of the availability from the intravenous doses based on area under the curve calculations for the average plasma level-time curves. The results demonstrate the need to sample the plasma as well as the bile before any conclusion can be made about reabsorption of a compound from the biliary ducts.
A comparative study of the effect of some centrally acting skeletal muscle relaxants in mice
Authors: Cymbalist M A , Shapero M 
Published: April 2011

Abstract
The possibility of differentiating between sedative-hypnotics and centrally acting muscle relaxants has been investigated in mice. The ED50 values for loss of muscle tone and loss of righting reflex were determined for 2-(3î,6î-dioxaheptyl) aminomethyl-1,4-benzodioxane (ambenoxan), 2-(4î,7î-dioxaoctyl) aminomethyl-1,4-benzodioxane (WB 4123) and compared with mephenesin, meprobamate, methocarbamol and the sedative-hypnotic, sodium pentobarbitone. Comparison of the slopes of the regression lines for hypotonia and loss of the righting reflex for the compounds suggests that ambenoxan offers a greater separation between the two responses than clinically used muscle relaxants.
A study of the interaction of tetracycline with human serum lipoproteins and albumin
Authors: Powis G 
Published: April 2011

Abstract
The interaction of 7-[3H]tetracycline at therapeutic concentrations with human serum proteins has been studied by dialysis and by molecular exclusion chromatography. In serum, 53% of tetracycline is in the form of complexes with protein: 54% with albumin; 13% with low density lipoprotein; 19% with high density lipoprotein; 6% with very high density lipoprotein and 8% with other serum proteins. Albumin possesses two binding sites for tetracycline, one a high affinity, low capacity site and the other a low affinity, high capacity site. At therapeutic concentrations three quarters of the tetracycline bound to albumin is associated with the low affinity site. Tetracycline appears to dissolve in the lipophilic portion of the lipoprotein molecule, rather than to be associated with specific binding sites.
Metabolism of heptabarbitone
Authors: Gilbert J N T , Millard B J , Powell J W , Whalley W B 
Published: April 2011

Abstract
The human metabolism of 5-ethyl-5-cycloheptenylbarbituric acid, heptabarbitone, Medomin, taken orally, has been studied. Comparison of g.c., and g.c.-m.s. data, from derivatized urine extracts, with data from authentic synthetic samples, has shown that 5-(3î-oxocycloheptenyl)-5-ethylbarbituric acid (II) and 5-(3î-hydroxycycloheptenyl)-5-ethylbarbituric acid (III) are major metabolites of heptabarbitone. In addition, similar data have been obtained for a third metabolite. There was no evidence for the presence of the parent drug in the urine of the two volunteers. The rate of urinary excretion of the three metabolites is briefly discussed.
The sorption of benzocaine from aqueous solution by nylon 6 powder
Authors: Richardson N E , Meakin B J 
Published: April 2011

Abstract
The sorption of benzocaine by nylon 6 powder from aqueous solution has been examined under varying environmental conditions. The extent of sorption increases with increase in electrolyte concentration, and with pH up to about pH 4. Increasing temperature reduces the amount of drug sorbed. In all cases, the sorption isotherms were linear over the concentration ranges studied, and can be described by a simple distribution law which allows the effects of ionic strength and pH to be predicted. The interaction is believed to involve hydrogen bond formation between benzocaine and the amide groups of the nylon after penetration of the polymer matrix by the drug.
In vivo estimation of tyrosine hydroxylation in the dopaminergic terminals of the rat neostriatum
Authors: Javoy F , Agid Y , Bouvet D , Glowinski J 
Published: April 2011

Abstract
An approach has been developed to distinguish dopamine synthesis from its release and utilization in dopamine terminals of the rat neostriatum (NCP). It enables a direct in vivo estimation of tyrosine hydroxylation, a rate limiting step in dopamine synthesis. Locally injected l-3,5[3H]tyrosine is converted to [3H]dopamine in the NCP. The conversion of the labelled tyrosine into [3H]dopa leads to local accumulation of [3H]water (3H-H2O). The initial accumulation (3 min) of the 3H-H2O levels in tissues gives a good reflection of the rate of tyrosine hydroxylation occurring in the dopamine terminals of the nigro-striatal pathway. In effect, 3H-H2O formation (1) disappeared after elective degeneration of the nigro-neostriatal dopamine neurons, (2) was inhibited by α-methyl-p-tyrosine, (3) was not affected by intraperitoneal injection of urea, which is known to reduce brain water content, (4) moreover, 3H-H2O accumulation was enhanced by various neuroleptic drugs and inhibited by (+)-amphetamine. Finally, Ro 4–4602 an inhibitor of dopa-decarboxylase reduced 3H-H2O formation 30 min after its injection.