bluuebunny/crossref_metadata_2025_split huggingface dataset:
The effect of acute bilateral adrenalectomy on vasopressor responses to catecholamines in dogs
Authors: Chopde C T , Brahmankar D M , Sheorey R V , Udhoji A G , Dorle A K 
Published: April 2011

Abstract
The effect of acute bilateral adrenalectomy on the pressor responses to adrenaline, noradrenaline and isoprenaline was studied in anaesthetized dogs. The responses to all the three catecholamines were reduced by adrenalectomy. Treatment with cortisone, cyclic AMP partially restored the responsiveness. Desoxycorticosterone, aldosterone, hydrocortisone, phenylbutazone or infusion of either saline and noradrenaline failed to improve the impaired pressor responses seen in adrenalectomized dogs. Treatment with corticosterone alone, combined administration of aldosterone and hydrocortisone or cortisone followed by cyclic 3′,5′-AMP also restored catecholamine responses almost to normal. The pressor responses to catecholamines in dogs were also reduced by metyrapone-induced cortical insufficiency. Administration of corticosterone, cortisone or cyclic AMP slightly improved these responses; the recovery was not, however, as effective as that noted in the adrenalectomized condition.
Differences between the anorexic actions of amphetamine and fenfluramine—possible effects on hunger and satiety
Authors: Blundell J E , Latham C J , Leshem M B 
Published: April 2011

Abstract
The inhibition of feeding in rats brought about by amphetamine and fenfluramine was continuously monitored for periods of up to 24 h using a pellet detecting eatometer. For rats tested under conditions of food deprivation the two drugs gave rise to distinctive anorexic profiles: amphetamine delayed the onset of eating whereas fenfluramine allowed eating to commence normally but brought about an early termination of the initial bout of feeding. When the drugs were administered to rats with free access to food, analysis of the meal pattern showed that amphetamine gave rise to a small increase in the inter-meal interval while fenfluramine brought about a clear reduction in meal size. It is suggested that the contrasting modes of action of these drugs represent an effect of amphetamine upon hunger and an action of fenfluramine on satiety. This suggestion is in keeping with the proposed mechanisms of action of these drugs, amphetamine acting upon a hypothalamic motivational system and fenfluramine acting by means of a postulated serotoninergic satiety system. Use of the continuous monitoring technique has pointed to certain limitations in the assessment of anorexic drug action by means of discrete food sampling periods.
Adrenergic responses of the rabbit stomach serosal strip and their modification by monoamine oxidase inhibitors and anti-adrenergic drugs
Authors: Khayyal M T , Tolba Hedayat , El-Hawary M B 
Published: April 2011

Abstract
The rabbit stomach serosal strip, was found to contract to adrenaline and noradrenaline but not to isoprenaline. The contractile response could be totally abolished by phenoxybenzamine but was not influenced by propranolol, indicating that the preparation has almost exclusively α-adrenoceptors. The responses to adrenaline and noradrenaline were markedly potentiated in the presence of monoamine oxidase inhibitors, guanethidine or reserpine, indicating the presence of MAO activity in the tissue and possibly catecholamine stores. The functional state of the latter has not been conclusively established, since tyramine, an indirectly acting amine, was unable to elicit a response qualitatively similar to that of adrenaline, even in the presence of nialamide or tranylcypromine.
The influence of dihydroxyanthracene derivatives on water and electrolyte movement in rat colon
Authors: Lemmens L , Borja E 
Published: April 2011

Abstract
The purgative activities of 18 different dihydroxyanthracene derivatives, including free anthraquinones and anthrones, were investigated by determining their influence on the water, sodium and potassium absorption in the gastrointestinal tract by direct injection of the solutions in Tyrode to the rat colon in situ. The extent of the solubility of the compounds has also been assessed. The 1,8-dihydroxyanthracene structure seemed to be the best for hydragogue effect. Rhein-anthraquinone and -anthrone were the most active compounds tested.
The granulation of binary mixtures
Authors: Opakunle W O , Spring M S 
Published: April 2011

Abstract
Granules have been prepared from blends of lactose and boric acid by the massing and screening method and their properties have been compared with those of granules from the individual materials, granulated separately. Increasing the volume of binder solution used produced granules stronger and of greater mean size in all blends studied. The largest and strongest granules, for any given binder solution volume and massing time, were obtained from a blend, as were the granules with the minimum pore size. The effect of massing time on granule properties was generally similar to those already reported for single component systems; prolonged massing in some blends led to a reduction in mean granule size. Variation in pre-mixing time produced no significant change in the physical properties of granules prepared from a lactose: boric acid blend.
Interfacial properties of polymethyl α-cyanoacrylate and polybutyl α-cyanoacrylate
Authors: Florence A T , Haq M E , Johnson J R 
Published: April 2011

Abstract
Several physical properties of two polyalkyl α-cyanoacrylates relevant to their use in pharmaceutical dosage forms have been investigated. Formation of polymer films at several oil-water interfaces reveals films of diverse morphology. The retardation of solute transfer across an oil-water interface caused by the presence of polymer films formed in situ from the monomers has revealed that the methyl derivative forms the more effective barrier to the test solute, gentian violet. The emulsion-stabilizing properties of the methyl polymer have been studied, and the film-forming properties of the monomers spread from benzene onto water surfaces have been examined using a surface balance.
Methylmercury and the skeletal muscle receptor
Authors: von Burg R , Landry T 
Published: April 2011

Abstract
Methylmercury at a bath concentration of 2 × 10−5 m was capable of inhibiting muscular contractions of the isolated rat phrenic-nerve hemidiaphragm preparation. At the height of inhibition, nerve action potential could still be recorded and the muscles continued to respond to direct stimulation. The inhibition was not reversible with l-cysteine or d-penicillamine but limited protection was possible by prior treatment with (+)-tubocurarine. Treatment of frog rectus muscles with methylmercury (0·2 Mm for 15 min) resulted in a shift to the right of 1 log unit in the dose response curve to acetylcholine and a reduction in the maximum response of the tissue. The observed inhibitory action of methylmercury on neuromuscular transmission may be explained by an action on the disulphide bond believed to be present on a cholinergic receptor.
Correlation of behavioural inhibition or excitation produced by bromocriptine with changes in brain catecholamine turnover
Authors: Snider Stuart R , Hutt Cheryl , Stein Bruce , Prasad A L N , Fahn Stanley 
Published: April 2011

Abstract
The dopamine agonist, bromocriptine, produced either inhibition or stimulation of motor behaviour in rats depending upon the dose and time after administration. Stimulation of motor activity occurred only with high doses after a 1–2 h delay. Both inhibition and stimulation were associated with decreased turnover of dopamine in the brain. Release of noradrenaline in brain and noradrenaline plus adrenaline in adrenal varied with motor activity. It is suggested that low doses of bromocriptine inhibit behaviour by activating an inhibitory presynaptic receptor, resulting in reduced synthesis and release of dopamine, whilst high doses cause behavioural excitation by activating the post-synaptic dopamine receptor.
Dopamine-sensitive adenylate cyclase in canine renal artery
Authors: Murthy Vadiraja V , Gilbert Jean-Claude , Goldberg Leon I , Kuo J F 
Published: April 2011

Abstract
To characterize further a putative dopamine receptor in the renal artery, the effects of dopamine on canine renal artery adenylate cyclase activity were studied. Since the femoral artery is thought to be devoid of a similar dopamine receptor, the effects of dopamine on the adenylate cyclase activity of the canine femoral artery were also studied. In tissues from dogs with or without phenoxybenzamine pretreatment, renal artery adenylate cyclase was maximally stimulated by 4 μm dopamine, compared to 20 μm required for the femoral artery enzyme. The concentrations of isoprenaline required to maximally stimulate renal and femoral artery adenylate cyclase were 0·04 and 0·2 μm, respectively. In tissue from the phenoxybenzamine-pretreated dog, the stimulatory effect of dopamine on the renal artery enzyme was selectively blocked by 0·01 μm haloperidol, but not by 0·2 μm propranolol. In the femoral artery, however, the dopamine stimulation was blocked by both antagonists. Stimulation by isoprenaline of renal and femoral artery adenylate cyclase was blocked by propranolol. These data suggest the concept that dopamine interacts with a specific artery receptor apparently different from α- and β-adrenoceptors.
Dioxygenated metabolites of cannabidiol formed by rat liver
Authors: Martin Bill , Agurell Stig , Nordqvist Marianne , Lindgren And Jan-Erik 
Published: April 2011

Abstract
The metabolism of cannabidiol (CBD) was studied in vitro using a 10 000 g supernatant from rat liver. After removal of unchanged CBD and its monohydroxylated metabolites, a polar fraction remained from which ten dioxygenated metabolites were isolated. Mass spectrometry and nuclear magnetic resonance spectroscopy were used to identify the following metabolites: 6,7-dihydroxy-CBD, 1″,7-dihydroxy-CBD, 3″,7-dihydroxy-CBD, 4″,7-dihydroxy-CBD, 5″,7-dihydroxy-CBD, 2″,6-dihydroxy-CBD, 3″,6β-dihydroxy-CBD, 4″,6β-dihydroxy-CBD (tentative), 3″-hydroxy-6-oxo-CBD, and 4″-hydroxy-6-oxo-CBD. The abundance of isolated dihydroxy metabolites reflected the quantity of monohydroxy metabolites that was previously found. In both series, 7-hydroxylation occurred to the greatest extent. Side chain hydroxylation occurred predominantly at C-4″ and to a lesser degree at C-3″. Trace amounts of metabolites were hydroxylated at C-1″, -2″, or 5″.
Effects of various diuretic agents in the mouse
Authors: Sim M F , Hopcroft R H 
Published: April 2011

Abstract
Diuretic effects of seven orally-acting diuretic agents have been examined in the mouse. The following compounds, examples of various types of orally active compound available, produced their characteristic diuretic effects: bendrofluazide, frusemide, ethacrynic acid, acetazolamide, triamterene, aminophylline and Su 15049A. The diuretic effects of the various agents were demonstrated under both water and saline-loading conditions. After allowing for differences in baseline sodium excretion, all diuretics except acetazolamide caused a further enhancement of sodium excretion after saline-loading compared with water-loading tests. The mouse possesses several advantages over the more commonly used rat since the range of diuretic responsiveness is greater. These results suggest that the mouse is a suitable species for diuretic testing.
Gels in soap stabilized emulsions
Authors: Pickett J M , Ellway K A 
Published: April 2011

Abstract
In some soap stabilized liquid paraffin emulsions a correlation has been found between emulsion type and the contact angle of the soap gel (the stabilizing agent) at the o/w interface. Two unrelated series of emulsions have been prepared, one series being stabilized by magnesium oleate gels and the other series by ammonium oleate gels. The soap gels were prepared by double decomposition and suppression of ionization respectively. Unlike the magnesium oleate system no inversion to w/o emulsions occurred with the ammonium oleate series. This dissimilarity is predicted from differences in the contact angles of the soap gels at the o/w interface.
Effect of disintegrant type upon the relationship between compressional pressure and dissolution efficiency
Authors: Khan K A , Rooke D J 
Published: April 2011

Abstract
Four tablet disintegrants: a relatively insoluble sodium carboxymethyl cellulose, casein formaldehyde, calcium carboxymethyl cellulose and a cross-linked polyvinylpyrrolidone have been evaluated. Three widely used disintegrants, sodium carboxymethyl cellulose, sodium starch glycolate and a cation exchange resin were included for comparison. The effect of compressional pressure on the disintegration and dissolution behaviours of a soluble and an insoluble system containing different disintegrants was examined. The results show that disintegrant type can have a pronounced effect upon the relationship between compressional pressure and dissolution efficiency. The significance of this relationship is discussed in terms of the properties of disintegrants and the differing mechanisms by which they act.
5-Hydroxytryptamine is a substrate for both species of monoamine oxidase in beef heart mitochondria
Authors: Mantle T J , Houslay M D , Garrett N J , Tipton K F 
Published: April 2011

Abstract
The activity of beef heart mitochondrial monoamine oxidase towards 5-hydroxytryptamine (5-HT) is inhibited by the selective inhibitors clorgyline, PCO [5-phenyl-3-(N-cyclopropyl)-ethylamine-1,2,4-oxadiazole] and Deprenyl with a biphasic dependence on the inhibitor concentration. The activities towards tyramine, dopamine and tryptamine were also inhibited in a biphasic manner, but the apparent proportions of the two enzyme species active on dopamine and tryptamine depended on the inhibitor used. Phenethylamine oxidation was inhibited in a monophasic manner suggesting that only a single enzyme species was responsible for the oxidation of this substrate. The biphasic response of 5-HT oxidation to inhibition by clorgyline persisted when functionally competent mitochondria were used and was unaffected by the soluble amine oxidase inhibitors semicarbazide and amino-guanidine. These results indicate that the behaviour of the beef heart enzyme towards selective inhibitors is considerably different from that of any preparations previously studied and suggest that the classification of monoamine oxidase activities into A and B types may be only of limited usefulness.
Bioanalysis of picomole amounts of acetylcholine by ion-pair partition chromatography applied to rat sciatic nerve
Authors: Ulin Birgitta , Gustavii K , Persson B-A 
Published: April 2011

Abstract
A method for determination of acetylcholine in small, discrete biological objects by use of ion-pair technique has been developed. Acetylcholine is extracted as an ion pair with 3,5-di-t-butyl-2-hydroxybenzenesulphonate and separated from co-extracted components by ion-pair partition chromatography with picrate as the counter ion and porous cellulose as support. The quantitative evaluation is made from the acetylcholine peak in the chromatogram obtained by ultraviolet detection. Acetylcholine has been analysed in 1 cm large pieces of rat sciatic nerve containing about 60 pmol (10 ng). The overall recovery of the method is 100 ± 10% at the 120 pmol level of acetylcholine in a sample.
Influence of various substances on prostaglandin biosynthesis by guinea-pig chopped lung
Authors: Fjalland B 
Published: April 2011

Abstract
Guinea-pig chopped lung tissue was used to investigate the inhibitory effect of various steroidal and non-steroidal anti-inflammatory agents, antipyretics, analgesics, local anaesthetics and psychotropic drugs on mechanically induced release of prostaglandin-like material. Low concentrations of non-steroidal anti-inflammatory agents inhibited synthesis, but other antipyretics and analgesics, and the local anaesthetics had little effect. Thymoleptics, neuroleptics and monoamine oxidase inhibitors except phenelzine exhibited weak activity. It is concluded that the method is a useful pharmacological model to study prostaglandin biosynthesis. The weak effects of the psychotropic drugs suggest that they do not exert their clinical effect by inhibiting PG biosynthesis.
Metabolic TV-oxidation of atropine, hyoscine and the corresponding nor-alkaloids by guinea-pig liver microsomal preparations
Authors: Phillipson J D , Handa S S , Gorrod J W 
Published: April 2011

Abstract
Incubation of guinea-pig liver microsomal preparations with atropine or hyoscine resulted in the formation of the corresponding nor-alkaloids and both isomers of atropine N-oxide from atropine and one isomer of hyoscine N-oxide from hyoscine. Separate incubations of guinea-pig liver microsomal preparations with nor-atropine and nor-hyoscine yielded the corresponding hydroxylamines. The N-oxide and hydroxylamine metabolites were identified by comparison of their t.l.c. behaviour and m.s. with prepared compounds and also by their reduction to the corresponding tertiary or secondary amines.
The microsomal N-oxidation of phentermine
Authors: Beckett A H , Bélanger P M 
Published: April 2011

Abstract
The microsomal N-oxidation of phentermine (Ia) to N-hydroxyphentermine (Ib) and to α,α-dimethyl-α-nitroso-β-phenylethane (Ic) was investigated. Maximum activities were obtained with microsomal (9000 g supernatant and microsomes) fractions of rabbit liver in the presence of an NADPH generating system. Incubation of Ia with hepatic washed microsomes from a phenobarbitone pretreated rabbit increased the formation of Ib and decreased that of Ic but the total amount of N-oxidized metabolites (i.e. Ib + Ic) was not affected. The ratio of the metabolically produced Ic to Ib but not the total amount of N-oxygenated metabolites varied greatly depending of the liver microsomal fractions used in the incubation mixtures of Ia; more Ib was produced from Ia using 9000 g supernatant and conversely, more Ic was formed using the washed microsomes of the same liver. The nitroso compound (Ic) was metabolically reduced to Ib and Ib to Ia by the hepatic 9000 g supernatant and soluble fraction; under the same conditions, washed microsomes had only limited reductive properties towards Ic and Ib. N-Hydroxyphentermine (Ib) was not metabolically oxidized to Ic when incubated with washed microsomes from rabbit liver. The use of known carbon-oxidation inhibitors showed that cytochrome P-450 is not involved in the incorporation of oxygen at the nitrogen centre of Ia. The metabolic characteristics and kinetic behaviour of the microsomal N-oxidation of Ia supported a recently proposed mechanism explaining the independent formation of Ib and Ic from a common precursor resulting from metabolic N-oxidation of Ia.
A new class of irreversible muscarinic antagonists: β-haloethylamine furoates
Authors: Rosen Gerald M , Rauckman Elmer J 
Published: April 2011

Abstract
The synthesis of a new class of ultra-long acting muscarinic antagonists is described. Furthermore, it is noted that the stability of the, in situ, aziridinium ion is sufficiently great so that these agents can be used to study the effect of temperature upon the conformation of the muscarinic cholinoceptor. The inactivation kinetics of these receptors as well as the dissociation constants, Kd, for all probes are presented.
The influence of polyvinylpyrrolidone on the dissolution and bioavailability of hydrochlorothiazide
Authors: Corrigan O I , Timoney R F , Whelan M J 
Published: April 2011

Abstract
The dissolution properties of hydrochlorothiazide - PVP 10 000 mechanical mix and co-precipitate systems were qualitatively similar to those previously reported using hydroflumethiazide. Quantitative differences were dependent on the proportion of PVP present, its molecular weight and method of incorporation. Cumulative urinary excretion data from test capsule preparations showed that bioavailability was enhanced by the presence of PVP. However, the degree of enhancement was less than that expected from constant surface area disc rate studies. Dissolution tests on the capsule formulations, using the U.S.P. basket stirrer assembly, did not correlate with in vivo results. Using the Levy beaker method and a stirring speed of 40 rev min−1, good correlation between amount dissolved in 30 min and amount excreted in urine after 24 h was obtained. The dissolution tests revealed that PVP retards the initial dissolution from capsule dosage forms, probably by retarding deaggregation and dispersion of drug particles.
Release of a drug from homogeneous ointments containing the drug in solution
Authors: Spang-Brunner Beatrice H , Speiser Peter P 
Published: April 2011

Abstract
The rate of release of resorcinol (5 %) from hydrogels (Carbopol, sodium carboxymethylcellulose, starch), lipogels (alcoholic-base, esteric-bases containing different amounts of beeswax with and without a spreading additive, respectively) and Labrafils has been examined. For the experimental design adopted the release of the drug is linear between 10 and 70% of the amount of drug released. The results agree well with the mathematical model postulated by Higuchi (1962) for the release of a drug from homogeneous ointments containing the drug in solution.
The absorption and elimination of metoclopramide in three animal species
Authors: Bakke O M , Segura J 
Published: April 2011

Abstract
The absorption and elimination of metoclopramide have been studied in the rat, rabbit and dog. Thin-layer chromatography followed by photodensitometry was used for the analysis of the unchanged drug and its metabolites. N-De-ethylation is an important Phase I metabolic reaction and conjugation with glucuronic acid and sulphate is a major route of metabolism, particularly in the rabbit. The pharmacokinetic parameters after intravenous administration showed little interspecies variation. First order elimination kinetics with short half-lives and high apparent volumes of distribution (&gt;1·1 kg−1) were observed. Major interspecies variations were seen after oral administration of high doses of the drug. Metoclopramide was eliminated slowly after oral administration to rats. The findings in the rabbit and in the dog suggest that the liver plays an active role reducing the systemic availability of unchanged metoclopramide after oral administration.
Kininogen and kininogenase synthesis by the liver of normal and injured rats
Authors: Borges D R , Gordon A H 
Published: April 2011

Abstract
Isolated livers from normal rats or from others at 2 days after subcutaneous injection of turpentine have been perfused with a simplified medium. Estimation of kininogen, kininogenase and 2 plasma proteins in the perfusates thus obtained indicate that both kininogen and kininogenase are synthesized in the liver. Furthermore, because twice as much kininogen and kininogenase was synthesized by the livers from the rats which had been injected with turpentine as by those from the normal rats, these two proteins must be considered to be members of the group of plasma proteins known as acute phase reactants.
An assessment of the cardiovascular sympathectomy induced by guanethidine
Authors: Blythe T H , Hall R C , Hughes I E 
Published: April 2011

Abstract
Guanethidine treatment of rats (30 mg kg−1, i.p. daily for 6 weeks) produced a profound reduction in the catecholamine present (as indicated by fluorescence histochemistry and catecholamine determinations) in tissues taken from the cardiovascular system, but there was evidence of the return of catecholamines within 8 weeks. While these changes are consistent with a sympathectomy, the unaltered pressor responses to physostigmine (100 μg kg−1, i.v.) and to carotid occlusion indicate an unimpaired functional capacity of noradrenergic nerves supplying the cardiovascular system. Although part of the response may be attributed to the unaffected adrenal medulla enhanced by the presence of considerable supersensitivity as shown to exogenous noradrenaline, there would appear to be a dissociation between the results obtained from physical and functional tests of the sympathectomy induced by guanethidine.