bluuebunny/crossref_metadata_2025_split huggingface dataset:
Plasma protein binding of frusemide in renal failure rabbits: investigation of endogenous protein binding inhibitors
Authors: Ikeda Katsumi , Yoshitomi Hironori , Nakayama Taiji , Goto Shigeru , Kimura Toshikiro 
Published: April 2011

Abstract
The reduction mechanism of frusemide-protein binding in the plasma of renal failure was investigated. The drug-albumin binding was inhibited by the low molecular-weight fraction obtained from acute renal failure rabbits, suggesting the presence of the inhibitors in the plasma. Further, this fraction was divided into six subfractions by Bio-Gel P-2. Fractions II and V2 showed significant inhibition of the protein binding of frusemide. Among uraemic toxins, four indole derivatives markedly inhibited the protein binding. Analysis by hplc confirmed that the concentration of indican was markedly increased in acute renal failure rabbit plasma. It is suggested that this compound could be one of the major inducers of the protein binding defect.
The effects of chronic inhalation of salbutamol on the acute airway responsiveness to salbutamol and ipratropium bromide in the conscious and the anaesthetized guinea-pig
Authors: Woodsford P V , Tomlinson D R , Ward M J , Palmer Julie P , Poole T R 
Published: April 2011

Abstract
The effects of chronic exposure to a nebulized mist of salbutamol on the capacity of systemic salbutamol to prolong the time taken for inhaled histamine to produce bronchospasm in guinea-pigs have been examined. Initially a reproducible cough time to inhalation of histamine acid phosphate (0·5 ml ml−1) in 100% O2 was established. Antagonism of this response by intraperitoneal salbutamol or ipratropium Br was assessed to establish submaximal responses to these drugs. A fresh group of animals was then exposed to a persistent mist of nebulized water for 16 days, before and during which each animal was tested by exposure to histamine mist either alone or shortly after salbutamol (10 μg kg−1 i.p.) or ipratropium Br (5 μg kg−1 i.p.). The nebulized water had no effect on the response to the drugs. The same animals were rested for 7 days and then exposed to nebulized salbutamol solution (5 mg ml−1) for 15 days, during which time tachyphylaxis developed to salbutamol (i.p.) but not to ipratropium Br. At the end of the 15 days the animals were anaesthetized and total lung resistance (RL) measured. At this time, the protective effect of intravenous salbutamol was also diminished by comparison with untreated guinea-pigs while the response to ipratropium Br was unaffected. A separate group exposed to 1 mg ml−1 of nebulized salbutamol for 20 days developed selective tachyphylaxis to intraperitoneal salbutamol. The animals were then allowed to breathe room air and the reponse to intraperitoneal salbutamol after 13 days returned to normal as did the effects of intravenous salbutamol on the RL response to histamine.
The role of opioid receptor sub-types in tifluadom-induced feeding
Authors: Jackson H C , Sewell R D E 
Published: April 2011

Abstract
There is now considerable evidence that opioid agonists and benzodiazepines increase food and water intake in a variety of animal species. The appetitive effects of the novel opioid-benzodiazepine tifluadom have been investigated. (±)-Tifluadom significantly increased food intake in freely-feeding rats. This stimulation of appetite was attributable principally to the activity of the (+)-isomer. Furthermore tifluadom-induced feeding was blocked by the opioid antagonists naloxone, naltrexone, Mr 1452 and Mr 2266 but not by the δ-opioid receptor antagonist ICI 154, 129, or by the benzodiazepine antagonist Ro 15–1788. These results suggest that tifluadom exerts its effect on food intake by interaction with opioid as opposed to benzodiazepine receptors and that this activity is mediated by κ and/or μ- rather than δ-opioid receptor sub-types.
Warfarin—sulfinpyrazone interaction on binding to human serum albumin
Authors: Larsen F G , Larsen C G , Brodersen R 
Published: April 2011

Abstract
Sulfinpyrazone displacement of warfarin from human serum albumin was studied in-vitro. At low sulfinpyrazone concentrations one molecule of warfarin is displaced on binding by one molecule of sulfinpyrazone. Clinical plasma concentrations of sulfinpyrazone are, however, too low to cause significant displacement.
o- and m-Iodohippurate binding to plasma proteins as a model drug transport mechanism
Authors: Lázníček M , Květina J 
Published: April 2011

Abstract
The pharmacokinetics of two isomers, o- and m-iodohippurate, were determined in rabbits and rats and the effect of protein binding on their elimination is demonstrated. Both isomers are rapidly eliminated by transport systems in the kidney and their clearance by the kidney approaches the renal plasma flow regardless of protein binding, m-Iodohippurate is more highly bound to plasma proteins than o-iodohippurate and its rate of elimination is enhanced in comparison with o-iodohippurate. In the case of these two isomers, the binding to plasma proteins should be considered as a transport mechanism and not as a storage depot.
The effects of phenylpropanolamine and other sympathomimetics on food consumption and motor activity in mice
Authors: Cairns M J , Foldys Janet E , Rees J M H 
Published: April 2011

Abstract
The effects of phenylpropanolamine on motor activity and on food intake were compared with those of S-amphetamine, ephedrine, 2-aminoindane and fenfluramine in groups of mice. Motor activity was additionally measured in mice pretreated with levodopa and benserazide, and food intake in mice pretreated with α-methyl-p-tyrosine. Amphetamine (2·5 mg kg−1) increased motor activity, phenylpropanolamine (10–40 mg kg−1) and 2-aminoindane (2·5–10 mg kg−1) decreased activity whilst ephedrine (2·5–40 mg kg−1) had a biphasic effect. Fenfluramine (10–40 mg kg−1) had negligible effect on activity. In mice pretreated with levodopa and benserazide both phenylpropanolamine and 2-aminoindane caused a massive increase in motor activity whilst fenfluramine’s action was not affected in the same way. Whilst the anorectic action of fenfluramine was considerably potentiated in mice pretreated with α-methyl-p-tyrosine, that of amphetamine, ephedrine, 2-aminoindane and phenylpropanolamine was either unaffected or initially antagonized. It is concluded that the mechanisms of motor and anorectic actions of phenylpropanolamine are similar to those of amphetamine.
Tensile strengths of paracetamol and Avicel powders and their mixtures
Authors: Bangudu A B , Pilpel N 
Published: April 2011

Abstract
Measurements were made of the tensile strengths of paracetamol and Avicel powders and of their mixtures. Two quantities were derived from the results; m, a universal constant whose value was 1·00 + 0·23 and α, a constant of the material. The value of α for paracetamol was much larger than that for Avicel and increased slightly with increase in particle size. Adding 25% w/w of Avicel to paracetamol produced a significant decrease in α and this fact may account for its use as an excipient in the tableting of paracetamol.
Development of an intravenous formulation for the unstable investigational cytotoxic nucleosides 5-azacytosine arabinoside (NSC 281272) and 5-azacytidine (NSC 102816)
Authors: Mojaverian P , Repta A J 
Published: April 2011

Abstract
In aqueous solutions 5-azacytosine arabinoside (aza-A) (NSC 281272) exhibits complex and rapid degradation of a type analogous to 5-azacytidine (aza-C) (NSC 102816). Consequently, it is not amenable for use as slow i.v. infusions. This study has determined that both compounds are relatively stable in dry dimethylsulfoxide (DMSO) or dimethylacetamide (DMA). In mixed aqueous-organic solvents, as the water content is reduced the rate of degradation is descreased. Based on these findings, aza-A may be dissolved in DMSO at 100 mg ml−1, sterile filtered, and sealed in ampoules. The contents appear to be adequately stable at 4 °C, and may at the time of use be diluted with water to yield a 70% DMSO solution which retains &gt;90% potency for 24 h at 25 °C and is compatible with commercially available i.v. infusion tubing. The diluted solution may be added in-line to a flowing i.v. vehicle, resulting in a physiologically acceptable solution in which the drug is unstable (t90 2 h). Its short residence time before reaching the bloodstream precludes any significant loss.
Renal aminopyrine demethylation in several species determined by a sensitive radiometric method
Authors: Ohno Yasuo , Kawanishi Toru , Takahashi Atsushi , Takanaka Akira , Kasuya Yutaka , Omori Yoshihito 
Published: April 2011

Abstract
Renal microsomal aminopyrine demethylation activities of several species were measured by a sensitive radiometric method using [dimethylamino-14C-]aminopyrine as a substrate and 2,4-dinitrophenylhydrazine as a trapping agent for the formaldehyde formed. The activity was highest in hamsters (0·75 nmol min−1 mg−1 protein) and that in rabbits, rats, mice, and guinea-pigs was 19·7, 7·0, 4·5 and 3·7%, respectively, of the hamster values. These species differences did not correlate with species differences in cytochrome P-450 content or in NADPH cytochrome c reductase activity. Aminopyrine demethylation activities in sliced renal tissues of several species were also compared. This activity was also found highest in hamsters (0·54 nmol min−1 g−1 wet tissue) and the activities in rabbits, rats, and guinea-pigs were 9·2, 1·8 and 2·5%, respectively, of the hamster values.
B-HT 958 stimulates dopamine autoreceptors but blocks noradrenaline autoreceptors in the brain
Authors: Grabowska-Andén Maria , Andén Nils-Erik 
Published: April 2011

Abstract
B-HT 958 (2-amino-6-(p-chlorobenzyl)-4H-5,6,7,8-tetrahydrothiazolo 5,4-d azepine) blocked the γ-butyrolactone-induced increase in the synthesis of dopamine and slowed down the α-methyltyrosine-induced disappearance of dopamine in the mouse brain by haloperidol-sensitive mechanisms. In reserpine-treated mice, B-HT 958 produced at most a weak locomotion and no change in the apomorphine-induced increase in motor activity. The motor activity of normal mice was reduced by B-HT 958. At high doses, B-HT 958 accelerated the α-methyltyrosine-induced disappearance of noradrenaline and it inhibited the effects of clonidine on the turnover and on the synthesis of noradrenaline in the mouse brain. The findings indicate that the dopamine autoreceptors can be selectively stimulated by B-HT 958 but that the α2-adrenoceptors can be blocked following high doses.
Presynaptic agonist effect of phentolamine in the rabbit vas deferens and rat cerebral cortex
Authors: Ennis C , Lattimer N 
Published: April 2011

Abstract
Clonidine inhibited the electrically-induced twitch response of the rabbit and rat isolated vas deferens preparations and also the K+-evoked release of [3H]noradrenaline from rat cortical slices. This effect of clonidine was antagonized competitively by yohimbine. Phentolamine inhibited the electrically-induced twitch response of the rabbit, but not the rat, vas deferens and in low concentrations (&lt;·1 μm) also inhibited the K+-evoked release of [3H]NA from rat cortical slices. These inhibitory effects of phentolamine were antagonized by yohimbine in a competitive manner but were not antagonized by indoramin, an α1-adrenoceptor antagonist. In the rabbit vas deferens, the effects of phentolamine were shown not to be due to the stimulation of β-, H1-, H2-, 5-HT- or muscarinic receptors. These results are consistent with the view that phentolamine can act as an agonist at presynaptic α2-adrenoceptors in the rabbit vas deferens and rat cortex but not in the rat vas deferens.
Nmr study of theophylline-ethylenediamine interaction in aqueous solution
Authors: Tashma Zeev 
Published: April 2011

Abstract
The behaviour of the H(8) nmr signal of theophylline in D2O solutions containing various amounts of ethylenediamine, indicates that in no case is the latter doubly charged, and so at an ethylenediamine to theophylline molar ratio of 0·5 (corresponding to that found in aminophylline) about half of the theophylline is present in a non-ionic form. At higher ratios an increase in its degree of ionization occurs, as evident from the continued upfield shift of the H(8) signal. The behaviour of the N-methyl signals differed from that of H(8). As the proportion of ethylenediamine increased from zero to 1·2 times that of theophylline, these signals first shifted upfield, but then moved back to approximately their initial positions. It is suggested that at low ratios, including that in aminophylline, the solution is composed of monocations of ethylenediamine paired to negatively charged aggregates of theophylline, in which both neutral molecules and ions co-exist. The ions thus act as solubilizing agents for the neutral, and usually slightly soluble, form of theophylline. At high ethylenediamine to theophylline ratios, the latter is fully ionized and the aggregates disintegrate.
Effect of egg yolk phospholipids plasma elimination and tissue distribution of coenzyme Q10 administered in an emulsion to rats
Authors: Yamaguchi Hiroyuki , Watanabe Keiichi , Hayashi Masahiro , Awazu Shoji 
Published: April 2011

Abstract
When coenzyme Q10 (CoQ10) in fat emulsion emulsified with egg yolk phospholipids (PL) was administered intravenously to rats, CoQ10 was eliminated more rapidly than when it was solubilized with a polyoxyethylene derivative of hydrogenated castor oil. Although CoQ10 in emulsion form is distributed mainly to liver, increase of PL concentration in the emulsion increased the distribution of CoQ10 to heart which is a target organ for CoQ10.
Invariable susceptibility to blockade by nifedipine of vasoconstriction to various α2-adrenoceptor agonists in pithed rats
Authors: Timmermans Pieter B M W M , Mathy Marie-Jeanne , Thoolen Martin J M C , De Jonge Adriaan , Wilffert Bob , Zwieten Pieter A van 
Published: April 2011

Abstract
The sensitivity of the increase in diastolic pressure brought about by the selective agonists of α2-adrenoceptors, B-HT 920, B-HT 933, xylazine, UK-14,304, M-7, TL-99 and DP-6, 7-ADTN in pithed normotensive rats to blockade by the calcium entry inhibitor nifedipine has been investigated. To exclude any participation of vascular α1- and β2-adrenoceptors, as well as cardiac β1-adrenoceptors, in the pressor responses, the study was made after treatment of the pithed rats with prazosin (0·1 mg kg−1) and (-)-propranol (1 mg kg−1). Without exception, the preferential agonists of α2-adrenoceptors elicited vasoconstrictor responses which were susceptible to inhibition by nifedipine (0·03–1 mg kg−1) in a dose-dependent manner regardless of the differences in intrinsic activity of the compounds. The pressor activity was almost completely abolished after 1 mg kg−1 of nifedipine. The results show that vasoconstriction induced in pithed rats by various selective stimulating agents of postjunctional vascular α2-adrenoceptors is invariably and equally sensitive to attenuation by nifedipine. This susceptibility of α2-adrenoceptor-mediated vasoconstriction to impairment by blockade of calcium entry is not dependent on the nature, the potency or the efficacy of the agonist.
Physicochemical properties of endotoxins in large volume parenterals
Authors: Baggerman C , Pathmamanoharan C , Spies F , Joosten J G H , Junginger H E 
Published: April 2011

Abstract
Endotoxins of Escherichia coli, Salmonella abortus equi and Serratia marcescens were examined using freeze-etch electronmicroscopy and light scattering techniques, with emphasis on their aggregation state. These endotoxins show distinct features of particle size and mass and they may be affected by the presence or absence of Ca2+ ions. No important differences were observed in the particle characteristics of the respective endotoxins in various infusion fluids.
Effects of saikosaponin-d on enhanced CCl4-hepatotoxicity by phenobarbitone
Authors: Abe Hiroko , Orita Machiko , Konishi Hiroyoshi , Arichi Shigeru , Odashima Shizuo 
Published: April 2011

Abstract
The effects of saikosaponin-d extracted from the roots of Bupleurum falcatum L. on increased toxicity of CCl4 and increased activities of microsomal enzymes induced by phenobarbitone have been examined. Saikosaponin-d showed protection against the CCl4-hepatotoxicity enhanced by phenobarbitone. It also inhibited increases in the content of cytochrome P450 and NADPH-cytochrome c reductase activity, which are induced by the phenobarbitone treatment, but the spectral characteristics of P450 were not altered. The rate of microsomal lipid peroxidation by NADPH and CCl4 was significantly lowered in-vitro in rats pretreated with phenobarbitone and saikosaponin-d compared with those pretreated with phenobarbitone alone.
The effect of temperature on the conductivity of gels and emulsions prepared from cetrimide and cetostearyl alcohol
Authors: Rowe R C , Patel H K 
Published: April 2011

Abstract
The conductivity of gels and emulsions containing cetrimide, cetostearyl alcohol, liquid paraffin and water has been studied over the temperature range +35 to −10°C. All samples froze at temperatures below −5°C and exhibited hysteresis on rewarming to room temperature with an initial increase in conductivity up to 15°C followed by a decrease to 25°C. The amount of hysteresis was dependent on the cetostearyl alcohol content and appeared to be related to changes in the microstructure of the liquid crystalline network.
A comparative study of the bioavailability of five different phenytoin preparations
Authors: Hirji M R , Measuria H , Kuhn S , Mucklow J C 
Published: April 2011

Abstract
The concentration of phenytoin in saliva has been measured in 8 healthy volunteers at intervals after an intravenous dose and after single oral doses of five formulations commercially available in the United Kingdom. The six doses (all 300 mg) were given in random order and at least one week apart. There were no significant differences in the mean values of the peak saliva concentration, the time-to-peak and the area under the saliva concentration-time curve between the five oral formulations. The absolute bioavailability of phenytoin varied between 68 and 74%.
Ring-substituted β-methoxyphenethylamines: a new class of psychotomimetic agents active in man
Authors: Lemaire D , Jacob P , Shulgin A T 
Published: April 2011

Abstract
Four members of a new class of psychotomimetic agents have been synthesized and evaluated in man. These compounds, which incorporate a β-methoxy group onto a β-phenethylamine sidechain, are the first reported psychotomimetics which are structural analogues of the neurotransmitter noradrenaline. These substances are more potent than the corresponding phenethylamines (lacking a β-methoxy group) but less potent than the correspondingly substituted amphetamine derivatives.
Location of the mechanism of the clonidine withdrawal tachycardia in rats
Authors: Jonkman F A M , Man P W , Thoolen M J M C , van Zwieten P A 
Published: April 2011

Abstract
Withdrawal of chronic infusion of clonidine elicits severe tachycardia and short-lasting blood pressure elevations (upswings). Withdrawal of clonidine in low dosage (30 μg kg−1 day−1 i.c.v., 7 days) elicited a maximum of 10.9 ± 0.5 upswings h−1. Cessation of s.c. infusion of clonidine (30 μg kg−1 day−1 7 days) evoked a maximum of 1.9 ± 0.5 upswings h−1. After cessation of the two clonidine infusions no overshoot of heart rate occurred. Withdrawal of a higher dose of clonidine (300 μg kg−1 day−1 s.c., 7 days), however, induced tachycardia (from 302 ± 8 to 433 ± 8 beats min−1) and 7.6 ± 1.4 upswings h−1. The administration of the α2-adrenoceptor antagonist yohimbine precipitated withdrawal tachycardia in animals treated with oxymetazoline, a hydrophilic α-adrenoceptor agonist. Yohimbine (3 mg kg−1 i.p.) precipitated a severe rise in heart rate from 285 ± 14 to 520 ± 5 beats min−1 in oxymetazoline (300 μg kg−1 day−1s.c., 7 days) treated rats and from 320 ± 13 to 420 ± 11 beats min−1 in saline-treated animals. Upswings were not induced by yohimbine treatment. It is concluded, that the blood pressure upswings after clonidine withdrawal are due to a central mechanism, whereas the mechanism of the overshoot of heart rate is located peripherally, probably at the cardiac presynaptic level.
Contraction induced by (-)-tartaric acid on rat isolated gastric fundus and its inhibition with indomethacin
Authors: Tug̀rul Levent , Özer Asli 
Published: April 2011

Abstract
Tartaric acid-evoked contractions of the rat isolated fundus could not be antagonized by atropine sulphate or methysergide hydrogen maleate, but were partially reduced by mepyramine hydrochloride. The contractions were prevented by indomethacin (25 μ ml−1) although the tissue remained sensitive to PGE2.
Effects of isoxicam and other non-steroidal anti-inflammatory drugs on arachidonic acid metabolism by rat peritoneal leucocytes
Authors: Tavares I A , Capasso F , Vine N D , Bennett A 
Published: April 2011

Abstract
Inhibition of prostaglandin formation from [14C]arachidonic acid by rat peritoneal leucocytes occurred with nonsteroidal anti-inflammatory drugs, their order of potency being indomethacin &gt; piroxicam &gt; naproxen &gt; ibuprofen &gt; isoxicam. At the lowest concentration tested (1 μg ml−1), indomethacin markedly increased the accumulation of lipoxygenase products in the cell incubates. Naproxen, ibuprofen or piroxicam 1 or 10 μg ml−1 resulted in smaller increases of lipoxygenase products, and there was only a small rise with these concentrations of isoxicam.
Pyridoxamine as inhibitor of the blood plasma benzylamine oxidase and other copper-containing amine oxidases
Authors: Buffoni F , Banchelli G , Dolara P , Ignesti G , Pirisino R , Raimondi L , Ziche M 
Published: April 2011

Abstract
Pyridoxamine inhibits rabbit and pig plasma benzylamine oxidase (BAO), the diamine oxidase of pig kidney and the lysyloxidase of pig aorta in-vitro. In-vivo in the rabbit, the inhibitory activity of pyridoxamine on plasma BAO is antagonized by an increase in the level of this enzyme that is dependent on an increase in rate of synthesis, there being no variation in the degradation rate constant.
Relationship between particle packing and the physical stability of powder mixes
Authors: Staniforth John N 
Published: April 2011

Abstract
The segregation tendency of powder mixes containing sugar-based direct compression tableting excipients with comparable particle size distributions and flow properties was studied under different vibration conditions. It was found that Tabfine and fine-particle pyridoxine hydrochloride mixes were virtually segregation-free, whereas segregation occurred in each of the other powder mixes containing Fast-flo, Dipac and Nu-tab. The segregation tendency of a specific powder mix following vibration was considered to be influenced by the packing of excipient particles in the powder bed. In general, the more densely packed the particles under given vibration conditions, the lower the segregation tendency. This was considered to be due to the tightly packed powder bed restricting individual particle movement and thereby reducing particle or ordered unit rearrangement.
Gastrointestinal transit of pellet systems in ileostomy subjects and the effect of density
Authors: Bechgaard Helle , Christensen F N , Davis S S , Hardy J G , Taylor M J , Whalley D R , Wilson C G 
Published: April 2011

Abstract
The transit of pellets of different densities (0.94 and l.96g cm-3) through the gastrointestinal tract of ileostomy subjects has been followed using the technique of gamma scintigraphy. In contrast with earlier reported results, the transit of the pellets was not affected by particle density.