bluuebunny/crossref_metadata_2025_split huggingface dataset:
Competitive blockade of adrenergic α-receptors and histamine receptors by thymoxamine
Authors: Birmingham A T , Szolcsányi J 
Published: April 2011

Abstract
The adrenergic α-receptor blocking activity of 4-(2-dimethylaminoethoxy)-5-isopropyl-2-methylphenyl acetate, thymoxamine, was quantitatively investigated on the vas deferens of the guinea-pig and on arterial strips from guinea-pigs, rabbits, cats and dogs. The blockade fulfilled the established criteria for competitive antagonism of noradrenaline. On these various tissues the pA2 was about 7.0; thymoxamine was more potent than piperoxan and less potent than dihydroergotamine. There was no evidence of β-receptor or 5-hydroxytryptamine receptor blocking activity. Against histamine as the agonist on the guinea-pig ileum, thymoxamine was a competitive antagonist with a pA2 of about 6.5.
Occurrence of anhydrovitamin A and retro-vitamin A in pharmaceuticals; their biological potency and effect on the assay of vitamin A
Authors: Varma T N R , Erdody P , Murray T K 
Published: April 2011

Abstract
Analyses of commercial samples of liquid multivitamin preparations revealed that many contained anhydrovitamin A, retro-vitamin A ether, vitamin A ether, and retro-vitamin A alcohol in varying proportions. Anhydrovitamin A and retro-vitamin A ether were present in greater amounts than the other vitamin A-derivatives. Anhydrovitamin A and retro-vitamin A ether had no measurable potency in the liver storage and vaginal smear assays, whereas retro-vitamin A acetate was 12% as potent as vitamin A. These compounds interfered with the assay of vitamin A by the United States Pharmacopeia XVI and British Pharmacopoeia 1963 methods but the interference could be eliminated by chromatography.
Quantitative separation of riboflavine from vitamin mixtures
Authors: Wahba Nagi , Fahmy Emil 
Published: April 2011

Abstract
A method for separating riboflavine from vitamin mixtures is described. The acidified aqueous solution is passed through a small column of large particle size talc on which the riboflavine is selectively and quantitatively adsorbed. Successive washings with 0–01 n hydrochloric acid and 5–10% dioxan remove the other components almost completely. The vitamin, eluted with 20% dioxan, is measured spectrophotometrically.
Some pyrroline derivatives as potential antiinflammatory agents
Authors: Beckett A H , Lee Calvin M , Sugden J K 
Published: April 2011

Abstract
Eight N-substituted-4-carbethoxy-2-oxo-3-hydroxypyrrolines and six N-β-phenethyl-2-oxo-3-arylaminopyrrolines were synthesised and tested for possible anti-inflammatory action. Infrared and nuclear magnetic resonance spectral evidence is presented to show that in the solid state and in solution (CDCl3) these compounds exist solely as the tautomer in which the double bond is within the heterocyclic ring. The compounds showed no important pharmacological activity.
A comparison of aralkylamines and aralkylguanidines as antagonists of adrenergic neurone blockade
Authors: FIELDEN R , GREEN A L 
Published: April 2011

Abstract
Structure-activity relationships have been studied for aralkylamines and aralkylguanidines which restore the responses of the nictitating membranes to nerve stimulation in anaesthetised cats given sympathetic blocking drugs. This reversing action was largely specific for adrenergic neurone blockade; blockade of sympathetic ganglia or of α-adrenergic receptors was unaffected. (+)-Amphetamine was the most active amine and N-benzyl-N-methylguanidine was the most active guanidine. In mice, ptosis resulting from adrenergic neurone blockade was much more readily prevented or abolished by the aralkylamines and aralkylguanidines than was ptosis caused by other types of sympathetic blocking agent. The most potent antagonist of ptosis was N-(2-phenylcyclopropyl)guanidine which was about ten times as active as amphetamine. The relative antagonistic potencies of 2 amines and 8 guanidines were virtually identical for all types of adrenergic neurone blocking drug, regardless of whether or not they cause noradrenaline depletion. The prevention of guanethidine-induced ptosis was always accompanied by some reduction in the extent of heart-noradrenaline depletion, but the minimum dose of antagonist required to prevent ptosis completely was always lower than that required to eliminate depletion.
The relation between noradrenaline content of rabbit heart muscle and the amount of k-strophanthin needed to produce arrhythmias
Authors: ANGELUCCI L , LORENTZ G , BALDIERI MIRELLA 
Published: April 2011

Abstract
Possible relations between the sensitivity of the heart to the arrhythmia-inducing property of k-strophanthin and myocardial storage of noradrenaline were investigated. Sensitivity to the glycoside was increased in rabbits pretreated with reserpine in doses which depleted noradrenaline, but not in rabbits pretreated with tyramine in doses which are known to reduce noradrenaline content. Sensitivity to the glycoside was restored to normal by an infusion of noradrenaline not earlier than 72 hr after reserpine treatment, but not by an infusion given at 24 hr. Infusion of noradrenaline did not itself reduce the sensitivity to k-strophanthin in normal rabbits. The glycoside acutely reduced the myocardial store of adrenaline and noradrenaline in normal rabbits. The possibility that cardiac sensitivity to k-strophanthin is regulated by bound but not by unbound noradrenaline is discussed.
A note on the assay of the contribution of the pentose phosphate pathway to glucose metabolism in human red cells
Authors: STURMAN J A , SMITH M J H 
Published: April 2011

Abstract
When human red cell suspensions were incubated with [14C1] glucose a substantial fraction of the incorporated radioactivity was found in phosphate compounds. If some of these phosphates are precursors of 14CO2 then an error is introduced into the conventional calculation of the proportion of glucose metabolised by the pentose phosphate pathway. The existence of this error was demonstrated and its magnitude was assessed by studying the effects of the subsequent addition of unlabelled glucose to the reaction mixtures in either the absence or the presence of methylene blue.
Some aggregation effects observed with an emulsion dispersed in saline containing cetrimide
Authors: GROVES M J 
Published: April 2011

Abstract
Aggregation behaviour has been observed when an emulsion containing liquid paraffin and cetostearyl alcohol as disperse phase is diluted in saline containing cetrimide below the critical micelle concentration. This aggregation has been examined with the Coulter Counter. Under standardised conditions the apparent size of the aggregated particles is directly related to the logarithm of the molar concentration of the cetrimide present over three orders of magnitude. Above the critical micelle concentration the particles appear to be deaggregated.
Modification of drug responses by hydrolytic Enzymes
Authors: CUTHBERT ALAN W 
Published: April 2011

Abstract
α-Chymotrypsin and phospholipase enzymes have been used to alter the cell membranes of the smooth muscle of the guinea-pig taenia coli. The effects of these treatments on the electrical and mechanical responses of the muscle to acetylcholine have been studied. Prolonged treatment with both enzymes causes depolarization with a consequent loss of acetylcholine sensitivity. After controlled trypsinization a membrane response to acetylcholine was obtained in the absence of a mechanical response. The sensitivity of the taenia coli to acetylcholine was depressed by controlled phospholipolysis without affecting the membrane potential or contractile apparatus. The implications of these findings are discussed.
The use of the Coulter Counter to detect the inactivation of preservatives by a non-ionic surface-active agent
Authors: PARKER M S , BARNES M , BRADLEY T J 
Published: April 2011

Abstract
Bacterial and mould spores undergo a germination swelling process which can be accurately measured using a Coulter Counter. The efficacy of preservatives can be assessed by their action in suppressing germination swelling of spores. The antagonism between polysorbate 80 and several preservatives has been demonstrated by measuring swelling of spores in the presence of preservatives and preservative-surfactant mixtures.
Effect of cold stress on the subcellular distribution of noradrenaline in the rat heart
Authors: CHANG C C , SU C Y 
Published: April 2011

Abstract
Rats were exposed to cold (4°) for 2 hr to study the effect of increased sympathetic activities on the subcellular distribution of noradrenaline in the heart. Cold-exposure caused about 30% decrease of total noradrenaline contents in both auricles and ventricles of normal or adrenalectomized rats. This depletion of noradrenaline caused by cold was completely prevented by pretreatment of the rat with hexamethonium chloride. Measurement of the subcellular distribution of noradrenaline revealed that the percentage depletion in particle-bound amine in both auricles and ventricles was greater than in the supernatant noradrenaline. It is suggested that the noradrenaline in the particulate fraction is the functional pool of the amine available for release by nerve impulses.
A new method for the determination of globule size distribution of emulsions by dielectric constant measurement
Authors: KAYE R C , SEAGER H 
Published: April 2011

Abstract
A new method for the determination of globule size distribution of emulsions prepared with non-ionic surfactants by ascent rate analysis is described. The proportion of dispersed phase in a narrow layer of dilute emulsion situated at a known height in a capacitance cell is determined at suitable time intervals and by the application of Stokes' Law, the droplet size distribution is calculated.
Steroidal monoquaternary ammonium salts with non-depolarizing neuromuscular blocking activity
Authors: LEWIS J J , MARTIN-SMITH M , MUIR T C , ROSS H H 
Published: April 2011

Abstract
A series of ten 2β- or 3α-steroidal monoquaternary ammonium salts, having androstane or pregnane skeletons and related in structure to acetylcholine by possession of an oxygen function on the carbon atom next but one to the quaternary nitrogen atom, were investigated for neuromuscular blocking activity in vivo in the cat, hen and mouse and in vitro on the frog rectus muscle and on the rat phrenic nerve diaphragm preparation. All compounds displayed typical non-depolarizing activity, the duration of block being significantly less than that for (+)-tubocurarine in the cat and the hen. The potency of the salts was low with the most active compound, 3α-acetoxy-2β-piperidino-5α-androstan-17-one methobromide, being 1/16th as active on a molar basis in the cat as (+)-tubocurarine.
Degraded and undegraded carrageenans and experimental gastric and duodenal ulceration
Authors: ANDERSON W , SOMAN P D 
Published: April 2011

Abstract
The prevention of histamine-induced gastric and duodenal ulceration in the guinea-pig has been examined using a series of undegraded and degraded carrageenans. Undegraded carrageenans were active at lower doses than degraded carrageenans. The high viscosity of the undegraded carrageenans in solution prevented their use in larger doses. Degradation of carrageenan without serious loss of sulphate, gives a product which allows the dose to be increased to an extent that its effect more than offsets the slight loss in activity caused by the degradation. No single feature of carrageenan structure can be related to anti-ulcer activity although degradation, and hence reduction of molecular size, generally reduces activity. Sulphate contents over 30% have little apparent effect on activity; κ-carrageenans were not consistently different in anti-ulcer activity from Λ-carrageenans. This contrasts with the antipeptic activity of carrageenans where κ-carrageenans are less active than their Λ-counter-parts. As with antipeptic activity, the degree of anti-ulcer activity is probably determined by a combination of structural features which includes molecular size and polyanionic properties.
Mechanism of the protective effect of reserpine on aggregated mice treated with (+)-amphetamine
Authors: MENON M K , DANDIYA P C 
Published: April 2011

Abstract
Experiments were made to see if the effect of reserpine in protecting aggregated mice from the toxic effect of (+)-amphetamine depended on the hypothermia or on the depletion of brain noradrenaline it induces. In aggregated mice, a 7 mg/kg dose of amphetamine elevated body temperature, lowered the level of brain noradrenaline and caused 100% mortality. In reserpinized aggregated mice, amphetamine did not cause hyperthermia or any further depletion of brain noradrenaline. Prevention of the hypothermic effect of reserpine by keeping amphetamine-treated reserpinized animals at a higher environmental temperature markedly lowered the protective effect of reserpine. When also the depletion of noradrenaline by reserpine was antagonized by dopa, reserpine no longer protected aggregated mice from the toxic effect of amphetamine. The lowering of 5-hydroxytryptamine content brought about by reserpine remained unaltered during these procedures. Complete protection against amphetamine toxicity was also offered by α-methyl-1-tyrosine in doses which lowered brain noradrenaline to almost the same extent as reserpine, but which did not lower temperature or brain 5-hydroxytryptamine. When the body temperature of aggregated mice with brain noradrenaline lowered by α-methyl-1-tyrosine was elevated by subjecting the animals to heat stress, the protective effect was reduced. Hypothermia induced by reserpine could thus be related to its noradrenaline-depleting action. The results show that both properties contribute to reserpine's protective action. However, the abolition by dopa of this protective effect of reserpine and the complete protection offered by α-methyl-1-tyrosine without hypothermia suggest that depletion of brain noradrenaline plays the more important role in the protective effect of reserpine.
Use of the analogue computer to predict the distribution and excretion of drugs under conditions of fluctuating urinary pH
Authors: Beckett A H , Boyes R N , Tucker G T 
Published: April 2011

Abstract
An analogue computer program, incorporating a previously established relation between urinary pH and amphetamine excretion, has been used to predict the quantitative excretion of the drug under normal conditions of fluctuating urinary pH. Under the same conditions, a comparison has been made of computer predicted body levels of amphetamine after administration of the drug in a single solution dose, three divided solution doses, and in various prolonged-release formulations. Advantages of sustained-release preparations are indicated and specifications for a theoretically ideal sustained-release formulation are suggested.
Cocaine-sensitive uptake of sympathomimetic amines in nerve tissue
Authors: Ross S B , Renyi A L , Brunfelter B 
Published: April 2011

Abstract
The uptake of [3H]octopamine, [3H]norephedrine and [3H]phenylethanolamine in slices of cerebral cortex and heart of the mouse was investigated. Cocaine inhibited the uptake of octopamine but had no effect on that of the other two amines, whose uptake seems to be a pure physico-chemical partition between the tissue and the solution. Together with previous results, these indicate that the cocaine-sensitive uptake is linked with the hydroxyl groups in the benzene nucleus and particularly with that in the meta position. The results bear out the view that the potentiating effect of cocaine on the direct effect of sympathomimetic amines is due to inhibition of the uptake of the amines in sympathetic nerves, but they contradict the assumption that the antagonizing effect of cocaine on the indirect action of the amines is due to inhibition of the amine uptake.
Toxicity of cryoprotective agents at 30°
Authors: Karow Armand M , Carrier Oliver , Clower Ben R 
Published: April 2011

Abstract
The toxicity of four cryoprotective agents (glycerol, dimethylsulfoxide, dextran, magnesium ion) as a function of time was assessed at 30° on isolated rabbit atria. Glycerol, 2·0 M, in Ringer solution killed all atria in less than 30 min. Atria tolerated 2·1 M dimethylsulphoxide in Ringer for 1 hr, 0·7 M glycerol in Ringer for 4 hr, 6% (w/v) dextran in saline for 6 hr and 6·6 times 10−2 M magnesium chloride in Ringer for 8 hr. After washing out the cryoprotective agents the tissue was examined histologically and for its response to isoprenaline, MJ-1999 [4,2-(isopropylamino-10-hydroxyethyl)methanesulphonilide, a β-blocking agent] and isoprenaline and ouabain. These tests were the more sensitive indicators of functional integrity.
Some aspects of the pharmacology of ibufenac, a non-steroidal anti-inflammatory agent
Authors: Adams S S , Hebborn P , Nicholson J S 
Published: April 2011

Abstract
When given orally to animals ibufenac has a range of potencies 2 to 4 times that of aspirin. It also suppresses thurfyl nicotinate erythema in man. Like certain other analgesic-anti-inflammatory-antipyretic drugs, when administered intravenously it suppresses bradykinin-induced bronchoconstriction in the guinea-pig. It has no glucocorticoid activity. Ibufenac, a compound chemically unrelated to existing antirheumatic drugs, can thus be classified as a non-steroidal anti-inflammatory (antirheumatic) agent.
The effect of the concentration of the water-soluble component, on the rheology of some oil-in-water emulsions containing long-chain alcohols
Authors: Talman F A J , Davies P J , Rowan E M 
Published: April 2011

Abstract
The effect of the concentration of two non-ionic water-soluble components—Sorbester Q12 (polyoxyethylene sorbitan monolaurate) and cetomacrogol 1000—and two ionic water-soluble components—cetrimide and sodium lauryl sulphate—on the rheology of some emulsions has been examined. Emulsions containing oleyl and lauryl alcohol exhibited an increase in consistency with increasing surfactant content. Maximum values for static yield value and apparent viscosity were found to occur with cetostearyl alcohol as the oil-soluble component. The values of the rheological parameters for products containing ionic surfactants tended to be higher than for non-ionics, but molal plots (and preliminary studies with Texofor N4, Texofor FX170 and Solumin FX170SD) suggested that this was an effect due to molecular weight rather than charge.
A note on a simple estimation of amphetamine, methylamphetamine and ephedrine in horse urine
Authors: Karawya M S , El-Keiy M A , Wahba S K , Kozman A R 
Published: April 2011

Abstract
A chromatographic separation of amphetamine, methylamphetamine and ephedrine from horse urine is possible on alkaline Silica Gel G plates developed with acetone-methanol (1:3). After elution, the bases are determined colorimetrically. The intensity of the violet colour resulting from the nitration of amphetamine is measured in a Unicam SP1300 colorimeter using filter No. 1 (sensitivity 50–250 μg). The colour produced by the interaction of methylamphetamine, sodium nitro-prusside, acetaldehyde and triethanolamine is measured at 590 mμ (sensitivity 200–2,000 μg). Ephedrine was determined by measuring the intensity of the brown colour of its dithiocarbamate at 440 mμ (sensitivity 100–900 μg).
Release of oxytocin contributes to the natriuretic action of aminophylline in rats
Authors: Lockett Mary F , Gwynne H L 
Published: April 2011

Abstract
Aminophylline, 0·25 to 2·0 mg intramuscularly, caused diuresis, natriuresis and increase in the Na/K of the urine in the 1 hr period after injection into normal hydrated or unhydrated rats. The urinary changes induced by 2 mg aminophylline and by 8 mU oxytocin equated. Salt-maintained adrenalectomized rats were fully sensitive to the diuretic, natriuretic action of aminophylline. The Na/K in the urine decreased at the 2 mg dose level. Hypophysectomy abolished and neuro-hypophysectomy markedly decreased the diuretic natriuretic action of aminophylline in unanaesthetized rats. Under ethanol-pentobarbitone anaesthesia the diuretic natriuretic action of 0·4 mg aminophylline intravenously lasted 30–40 min in normal rats, and for less than 10 min in neurohypophsectomized rats. The duration of the cardiovascular response to aminophylline was 7–8 min. Thioglycollate-labile oxytocic activity, not detectable in the arterial plasma of control animals, was demonstrable in the arterial plasma of normal rats 8–12 min after 0·5 mg aminophylline intravenously.
The determination of bupivacaine, lignocaine and mepivacaine in human blood
Authors: Reynolds Felicity , Beckett A H 
Published: April 2011

Abstract
A specific method for the quantitative analysis of bupivacaine, lignocaine and mepivacaine in blood, in clinically occurring concentrations, using gas-liquid chromatography, is described. The extraction procedure yields a recovery of 97·5 (±5)%, and the chromatographic conditions allow concentrations as low as 0·04 μg/ml of local anaesthetic in 2 ml of whole blood to be measured. The method has a standard deviation of 5·4%. No interference is encountered from commonly used premedicant or general anaesthetic drugs.
The extraction of azovan blue from precipitated plasma proteins
Authors: Gardiner J E 
Published: April 2011

Abstract
The paper describes a method for the estimation of azovan (Evans) blue in plasma proteins precipitated by trichloroacetic acid. The precipitate is dissolved in a strong solution of urea and an anionic detergent; the dye is absorbed on a cellulose column, from which it can be eluted by alkaline acetone-water. The method allows information to be obtained about drug uptake and plasma volume without the need for additional blood samples. It has been used with cat, rabbit, rat and guinea-pig plasma.
Effects of nicotine on motor co-ordination and spontaneous activity in mice
Authors: Morrison Cathleen F 
Published: April 2011

Abstract
Doses of nicotine (0·2 and 0·4 mg/kg subcutaneously) which depress spontaneous activity, improve the ability of mice to remain on a rotating rod, indicating that the reduction in activity is not due to non-specific disruption of motor ability.
The performance of rats trained to press a bar for water rewards is stimulated by small subcutaneous doses (0·05, 0·1 mg/kg) of nicotine; larger doses (0·2, 0·4 mg/kg) briefly reduce the rate of bar-pressing before increasing it (Morrison, 1967). The larger doses also depress spontaneous motor activity in mice (Morrison & Armitage, 1967). In the present experiments a rotating rod (Dunham & Miya, 1957) was used to test whether the depresssion of spontaneous activity caused by nicotine is a result of motor incapacity.
The mechanism of action of 2-halogenoethylamines at the adrenergic α-receptor and a further investigation of the “spare receptor” hypothesis
Authors: Moran J F , Triggle C R , Triggle D J 
Published: April 2011

Abstract
The evidence for “spare-receptors” has been examined in the adrenergic α-receptor system of the rat vas deferens using N-(2-bromoethyl)-N-ethyl-l-naphthylmethylamine (SY.28) and NN-dimethyl-2-phenylethylamine hydrobromides as the antagonist species. It is clearly demonstrated that “spare-receptors” are not present in this tissue and that the observed parallel shift of the dose-response curve of noradrenaline produced by SY.28 is due to a competitive reversible phase of action of the corresponding ethyleneimine species rather than to the presence of “spare-receptors”. Additionally, these experiments have revealed the existence of a significant non-competitive reversible phase of action of SY.28. From radiochemical studies and the observed first order recovery of tissue response following blockade by NN-dimethyl-2-bromo-2-phenylethylamine, it is concluded that the α-receptors in the rat vas deferens are indistinguishable from the α-receptors in the rabbit aorta in their behaviour towards this agent. From these results and those of others, it may be concluded that there is no existing evidence for “spare receptors” in adrenergic α-receptor systems.