bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effect of reserpinization on insulin secretion in the rat
Authors: KAWADA TSUTOMU , ITAYA KOICHI 
Published: April 2011

Abstract
Reserpine-induced supersensitivity to the insulin-releasing action of a β-adrenergic agonist, isoprenaline, and of glucose was studied in vivo and in vitro. The subcutaneous injection of rats with reserpine (0.05 to 10 mg kg−1) enhanced the action of isoprenaline on insulin secretion. ED50 of isoprenaline for insulin secretion was changed little after reserpinization, whereas maximum effect of the β-agonist was enhanced by pretreating rats with reserpine. Glucose-stimulated insulin secretion was also enhanced in the reserpinized rats. Pancreases isolated from the reserpinized rats secreted more insulin in response to phentolamine in the presence of glucose and isoprenaline. These results suggest that the supersensitivity in insulin secretion induced by reserpine may be non-specific.
Catecholamines act at α2-adrenoceptors to cause contraction of circular smooth muscle of guinea-pig stomach
Authors: SAHYOUN H A , COSTALL B , NAYLOR R J 
Published: April 2011

Abstract
Circular smooth muscle strips taken from the body region of the guinea-pig stomach responded to dopamine and noradrenaline with contraction at lower concentrations followed by relaxation at higher concentrations. A (β-adrenoceptor-mediated relaxation response was excluded by propranolol treatment and this allowed the remaining α-adrenoceptor involvement with relaxation and contraction to be incisively differentiated in terms of two distinct α-adrenoceptor mechanisms. Thus, the relaxation responses to the catecholamines were mimicked by phenylephrine and antagonized by prazosin, phentolamine but not by yohimbine or rauwolscine. In contrast, the catecholamine-induced contractions were mimicked by clonidine and antagonized by yohimbine and phentolamine but not by prazosin. It is therefore concluded that the α mechanisms via which dopamine and noradrenaline are able to relax and contract the circular smooth muscle from the body region of guinea-pig stomach are of the α1- and α2-type respectively.
Stabilization of water/oil/water multiple emulsions by polymerization of the aqueous phases
Authors: Florence A T , Whitehill D 
Published: April 2011

Abstract
In order to improve the stability of w/o/w multiple emulsions which have isopropyl myristate as the non-aqueous ‘oil’ phase, either the internal aqueous phase of the multiple system or the secondary (outer or continuous) aqueous phase can be gelled. Production, by γ-irradiation, or cross-linked polyacrylamide or poloxamer gels in the aqueous phases of the emulsions leads to systems which have a greater intrinsic stability than untreated multiple emulsions. If the internal aqueous phase is gelled this prevents coalescence. When the continuous outer phase is gelled an opaque emulsion is produced in which the disperse w/o droplets are held in a hydrophilic polymer network from which the droplets are released on contact with water.
Effect of vibration time, frequency and acceleration on drug content uniformity
Authors: Staniforth John N , Rees John E 
Published: April 2011

Abstract
The effect of different vibration conditions on the segregation tendency of three ordered powder mixes was studied. Segregation of the powders was measured using a cylinder, composed of interlocking units for sampling purposes, mounted on a vibration rig. Ordered mixes containing either Emdex or recrystallized lactose carrier particles mixed with 0.5% fine-particle potassium chloride were stable, except for slight segregation that occurred under severe vibration conditions at frequencies below 50 Hz and accelerations above 22 m s−2. Powder mixes of Dipac with potassium chloride were unstable at most vibration conditions from 20 to 1000 Hz and 7.4 to 29.4 m s−2. The intensity of segregation in vibrated mixes of Dipac with potassium chloride was most marked at frequencies below 50 Hz and accelerations above 22 m s−2. These vibration conditions were found to occur in several commonly-used types of tableting presses. When vibration was prolonged, for periods of 30 to 60 min, there was increased segregation found in ordered mixes.
The effect of oils on the lymphatic absorption of DDT
Authors: Palin K J , Wilson C G , Davis S S , Phillips A J 
Published: April 2011

Abstract
Plasma concentrations of DDT were measured in conscious rats following oral administration in arachis oil, Miglyol 812 (fractionated coconut oil), liquid paraffin or as a fine suspension in water. The total absorption of DDT, calculated as the area under the plasma concentration time curve, was significantly greater for the arachis oil formulation compared to the other vehicles. In anaesthetized rats it was shown that DDT absorption was almost totally via the lymphatic system, and that lymph levels of DDT were highest following administration in arachis oil. Measurement of lymph flow showed that this enhanced absorption of DDT in the presence of arachis oil was not due to an increased flow as both arachis oil and liquid paraffin stimulated lymph production to the same extent.
Transamination and other metabolic pathways of 3,4-dihydroxyphenylpyruvic acid in rats when simultaneously administered with L-dopa
Authors: LindéN I-B , Karlsson M , Niemi S , Penttilä A 
Published: April 2011

Abstract
In the rat, 3,4-dihydroxyphenylpyruvic acid (DHPPA) was shown to be transaminated to L-dopa when administered orally concomitantly with L-[3H]dopa. As much as 40% of the serum L-dopa and brain dopamine was shown to be formed via transamination. Moreover, it was shown that DHPPA also caused a so-called L-dopa-sparing effect, i.e. more administered L-dopa reached the circulation and consequently more dopamine reached its target than after administration of L-dopa alone. This effect might be due to an inhibition of the deamination of L-[3H]dopa, since in this case the equilibrium of the transamination reaction will be forced into the L-dopa-forming direction. After administration of [14C]DHPPA alone and together with L-dopa, no differences in the absorption and distribution of radioactivity were found.
An evaluation of starch obtained from plantain Musa paradisiaca as a binder and disintegrant for compressed tablets
Authors: Esezobo S , Ambujam V 
Published: April 2011

Abstract
The binding and disintegrant properties of plantain starch obtained from Musa paradisiaca, family Musaceae, have been evaluated. Its effect in tablets of paracetamol and chloroquine phosphate on their physical properties such as hardness, friability and disintegration time was compared with tablets prepared with maize starch. The results show that plantain starch can be used both as a tablet binder and disintegrant in the preparation of tablets and the indication is that plantain starch has about twice the binding efficiency and about half the disintegrant power of maize starch.
Gas chromatographic determination of pargyline and pargyline amine metabolites after derivatization with isobutyl chloroformate
Authors: Weli Afaf M , Ahnfelt Nils-Otto , Lindeke BjöRn 
Published: April 2011

Abstract
Pargyline (I) and four of its major amine metabolites, N-benzylpropargylamine (II), N-methylpropargylamine (IV), N-benzylmethylamine (VI) and pargyline N-oxide (VIII), were determined by g.l.c. after reaction with isobutyl chloroformate in a two-phase system. Pargyline and metabolite IV which form the same derivative, were separated quantitatively by liquid-liquid distribution before derivatization with isobutyl chloroformate. Also, metabolites VI and VIII form identical derivatives, and as they could not be easily separated, VIII was reduced to I before derivatization. The analytical method was applied in studies of the metabolism of pargyline in microsomes from phenobarbitone pretreated rats. The metabolism was rapid, leading mainly to the formation of II, IV, VI and VIII. 92% of the substrate was consumed during the first min of incubation at an initial substrate concentration of 100 μM (32 nmol mg−1 protein), and II, IV, VI and VIII accounted for 83% of formed metabolites. The metabolite II was further metabolized while the levels of IV, VI and VIII remained constant after 5 min. It was possible to determine 0.5 μM of pargyline, II and VI in microsomal incubations, with an r.s.d. of &lt;5% (n = 6). N-Methylpropargylamine (IV) was positively identified and quantitated as a pargyline metabolite for the first time.
Effects on tracheal smooth muscle of adenosine and methylxanthines, and their interaction
Authors: Karlsson J-A , Kjellin G , Persson C G A 
Published: April 2011

Abstract
The relaxant effects of xanthine and 15 different methylxanthines were studied in a guinea-pig isolated tracheal ring preparation. Substitution in the 3- and 1-positions of the xanthine molecule were found to be of greatest importance for improving tracheal relaxant potency. The unsubstituted xanthine and all 9-methylated xanthines were weakly active. Adenosine occasionally contracted (slightly) the tracheae but a concentration-dependent relaxation was always recorded. Endogenous adenosine did not seem to contribute to the tracheal tone. Xanthines methylated in the 1-position consistently antagonized the relaxant effect of adenosine and produced graded rightward shifts of the concentration-response line to adenosine (competitive antagonism). Xanthines with an unsubstituted 1-position or with comethylation in the 9-position were generally without antagonism. The results support our view that bronchodilating xanthine derivatives lacking universal adenosine antagonism can be produced.
Morphine intake from poppy seed food
Authors: Bjerver Kjell , Jonsson John , Nilsson Anna , Schuberth Jan , Schuberth Jutta 
Published: April 2011

Abstract
Morphine was determined in commercially available poppy seed and seed cake as well as in urine from healthy normal human adults 3 and 15 h after ingestion of poppy seed cake. The following morphine concentrations were determined: between 374 ±51 and 9.4 ± 1.0 μmol kg−1 poppy seed of different brands, 290 ± 11 μmol kg−1 poppy seed paste, 1.43 ± 0.07 and 0.53 ± 0.15 μmol litre−1 urine sampled 3 and 15 h, respectively, after ingestion of two cakes and 0.67 ± 0.17 and 0.30 ± 0.06 μmol litre−1 urine sampled 3 and 15 h, respectively, after ingestion of one cake. It is concluded that a positive finding of morphine in the urine from a person suspected of heroin abuse calls on some attention due to possible accidental morphine intake from poppy seed food.
Compressional characteristics of four starches
Authors: Paronen P , Juslin M 
Published: April 2011

Abstract
Compression data about barley, corn, potato and wheat starches were obtained by two methods: the ejected tablet method and the tablet-in-die-method. These data were analysed using the Heckel and the Cooper-Eaton equations. The Heckel equation appeared to be the more sensitive in distinguishing the various stages during the compression. Die filling and rearrangement processes for the starches were especially dependent on particle size and shape and thus on contact area between particles. Densification of large starch particles (potato starch) owed more to die filling and less to rearrangement. Densification of small particles (corn starch) was the reverse. Starch having a wide particle size distribution (wheat) or an irregular particle shape (barley) underwent a relatively small amount of densification as a result of die filling and a relatively great amount of densification because of rearrangement of particles during tableting. The tendency of the starches to total and pure plastic deformation was dependent on particle size, size distribution and particle shape. Corn starch was the most prone to plastic flow with only little elastic recovery. Potato starch also flowed plastically with ease. Barley and wheat starches were the more elastic.
Intestinal contribution to the presystemic elimination of β-phenethylamine in the rat
Authors: Worland P J , Ilett K F 
Published: April 2011

Abstract
The metabolism of β-phenethylamine (PEA) has been investigated in intestinal, liver and lung homogenates from the rat. Metabolic activity was ranked liver &lt;&lt; lung &lt;&lt; duodenum &lt; jejunum &lt; ileum &lt; colon. Absorption and metabolism of PEA was also studied using in-situ intestinal loops from rats. Absorption of PEA appeared to be a passively mediated process with metabolism occuring in the jejunum, ileum and colon. When isolated loops of jejunum were used, phenylacetic acid was the only metabolite formed. Presystemic elimination of PEA in anaesthetized rats, was largely attributable to the intestine and lung with a relatively small hepatic contribution.
Digoxin-specific antibody fragments and a calcium antagonist for reversal of digoxin-induced mesenteric vasoconstriction
Authors: Hess T , Scholtysik G , Salzmann R , Riesen W 
Published: April 2011

Abstract
The effect of digoxin-specific antibody fragments on glycoside-induced mesenteric vasoconstriction were investigated. Digoxin caused a sustained contraction of strips of isolated feline mesenteric artery lasting for several hours, while in anaesthetized cats it produced a significant decrease in blood flow and increase in resistance in the mesenteric artery. In-vitro, digoxin’s contractile effect was inhibited by ‘prophylactic’ addition of antibody to the organ bath, but the clinical use for prophylaxis is not a practical proposition. When the antibodies were added with the contraction of the arterial strip in response to digoxin already established, the tone of the preparation decreased significantly over 3 h, but the effect of the glycoside was not fully reversible. In-vivo, control animals not treated with antibodies developed arrhythmias, mesenteric blood flow fell by more than 50% and resistance increased by more than 80% relative to the initial values. These animals died of ventricular fibrillation before the end of the experiment. Animals treated with digoxin-specific antibody fragments after receiving digoxin injections showed no further decrease in mesenteric blood flow and 90 min after the last dose of digoxin, the flow was recovering and mesenteric resistance decreasing. Furthermore, all the animals that had received antibodies remained in sinus rhythm to the end of the experiment. In view of the latent period to onset of action of the antibodies, valuable time may be lost in impaired mesenteric blood flow. To bridge the gap or, indeed, as primary treatment, calcium antagonists merit consideration; in our experiments mesenteric vasoconstriction was abolished within a few minutes by application of the dihydropyridine calcium antagonist 4-(2,1,3-benzo-oxadiazol-4-yl)-2,6-dimethyl-1,4-dihydropyridine-3,5-dicarboxylic aid, diethyl ester (PY 108–068).
Mechanisms of antibacterial formaldehyde delivery from noxythiolin and other ‘masked-formaldehyde’ compounds
Authors: Gidley Michael J , Sanders Jeremy K M 
Published: April 2011

Abstract
Formaldehyde release in aqueous solutions of noxythiolin (N-methyl-N'-hydroxymethyl thiourea) has been monitored by nuclear magnetic resonance (n.m.r.) spectroscopy. The results suggest that antibacterial activity in such solutions resides mainly in the free formaldehyde. N.m.r. spectroscopy also demonstrated slow C-N bond rotation in noxythiolin and N-methylthiourea, with ΔG‡ of ca 15 kcal mol−1 (63 kJ mol−1)-N-Hydroxymethyl imidazole is marginally more effective than corresponding hydrated formaldehyde solutions, an effect which is attributed to more rapid turnover of unhydrated formaldehyde as detected by saturation transfer n.m.r. spectroscopy. These observations are combined with the known delivery of lethal iminium ions, R2N+=CH2, by compounds of the form R2NCH2X (X = OH, NR2; R is alkyl) to suggest a single consistent explanation of the antibacterial properties of a wide range of masked formaldehyde compounds.
Impairment of drug metabolism by the liver in experimental fascioliasis in the rat
Authors: Galtier P , Battaglia A , More J , Franc M 
Published: April 2011

Abstract
Fascioliasis has been produced in the rat by an oral administration of 20 metacercariae of Fasciola hepatica. Hepatic microsomal cytochrome P450 and b5 contents and both aminopyrine demethylase and aniline hydroxylase activities have been measured during the course of the experimental distomiasis. The cytochrome P450 concentration and microsomal drug metabolizing enzymes generally fell by weeks 3 to 8 post-infestation and recovered to normal values thereafter. For the same period, both the histoenzymatically assayed liver cytochrome oxidase and arylsulphatase activities were reduced whereas there were correlated increases in glutamic pyruvic and glutamic oxaloacetic plasma transaminases. Tissue inflammation and destruction provoked by young histophagous migrating flukes could be responsible for these changes that have already been observed in several hepatic diseases. The possible influence of naturally-induced fasciolasis on liver drug metabolism is discussed.
A monoamine oxidase-B inhibitor, MD 780236, metabolized essentially by the A form of the enzyme in the rat
Authors: Benedetti Margherita Strolin , Dow James 
Published: April 2011

Abstract
In-vivo studies on the metabolism of [14C]MD 780236 a short-acting selective type B MAO inhibitor in the rat showed the acid to be the major metabolite in plasma and urine, whereas it was minor in brain, where the alcohol was the major metabolite. Pretreatment with SKF 525-A did not modify the metabolite profile in brain, but benserazide decreased the alcohol. Pretreatment with (-)-selegiline had no effect, but clorgyline or clorgyline with (-)-selegiline significantly decreased the alcohol and increased the primary amine metabolite in brain. In-vivo results suggest that MAO-A is the enzyme responsible for the metabolism of MD 780236. This was confirmed by in-vitro studies. Rat brain homogenates extensively metabolized the drug, with the aldehyde being the major metabolite formed (28% of the total radioactivity in the incubation mixture after 60 min incubation). The acid (12%) was more important than the alcohol (4%) in-vitro. The addition of all metabolites originating from possible MAO activity gave 46% when the incubation was carried out at pH 7·4 and 82% at pH 8·8. The presence of NADPH or NAD+ did not alter the relative amounts of metabolites formed. Total metabolites originating from MAO activity in the presence of (-)-selegiline accounted for 40% of total radioactivity, whereas in the presence of clorgyline they accounted for 8% and in the presence of both clorgyline and (-)-selegiline they were reduced to 3%, compared with 45% in controls. As a further proof of the importance of MAO-A in the metabolism of MD 780236, rats were pretreated with clorgyline 1 h before the drug and MAO-B inhibition measured at different times ex-vivo in brain and liver. The short-lasting phase of inhibition of MAO-B disappeared after pretreatment with clorgyline, and inhibition at 24 h was as high as that at 1 h. These results demonstrate the importance of the A form of MAO for the metabolism of MD 780236.
Stability and functional properties of haemoglobin freeze-dried in the presence of four protective substances after prolonged storage: dose-effect relationships
Authors: Labrude Pierre , Vigneron Claude 
Published: April 2011

Abstract
Freeze-dried haemoglobin samples protected during the desiccation by sucrose, arginine aspartate, lysine aspartate, sodium-zinc EDTA and Ficoll 70 have been stored under air at 4 †C for 15 months. The analysis showed that sufficient concentrations of sucrose and of the amino-acid salts prevent the oxidation of haemoglobin and maintain its functional properties. Relationships between the concentrations of these compounds and the methaemoglobin levels before and after storage were calculated. They define theoretical concentration points where methaemoglobin would not be found after storage. Sucrose is slightly more effective than the amino-acid, but oppositely, EDTA and Ficoll 70 do not allow prolonged storage of freeze-dried haemoglobin.
Actions of neurotransmitters and peptides on longitudinal and circular muscle of the rat portal vein
Authors: Mathison Ron 
Published: April 2011

Abstract
The reactivity of longitudinal and circular muscle of the rat portal vein to noradrenaline, acetylcholine, 5-hydroxytryptamine, substance P, angiotensin II and neurotensin was compared. Longitudinal muscle was prepared as longitudinal strips and circular muscle was studied as transversally cut rings. Longitudinal muscle was more sensitive than circular muscle to acetylcholine, 5-hydroxytryptamine and angiotensin II, whereas both muscle layers were equally sensitive to noradrenaline and substance P. Circular muscle was generally unresponsive to neurotensin. Differential sensitivity of longitudinal and circular muscle layers suggests that these two muscle layers do not necessarily operate in unison.
α2-Adrenoceptor agonist properties of exo- and endo-isomers of 2-amino-6,7,dihydroxybenzo-norbornene designed as rigid catecholamines
Authors: Hicks P E , Waldron C , Burn P , Crooks P A 
Published: April 2011

Abstract
A series of N-substituted exo- and endo-isomers of 2-amino-6,7-dihydroxybenzo-norbornene, designed as rigid catecholamines, have been studied in the pithed rat in-vivo, as vasoconstrictor agents, and as inhibitors of the twitch response in the transmurally stimulated guinea-pig ileum. The exo-isomers examined were vasoconstrictor agonists in the pithed rat and inhibited the twitch response of the ileum. The corresponding endo-isomers were inactive in both preparations. The exo-isomers were less potent than the α2-receptor agonist TL99, but were all directly acting vasoconstrictor agents, since they were still effective in reserpine-pretreated animals. Responses induced by members of the exo-series were selectively antanonized by the α2-receptor antagonist rauwolscine, but were not antagonized by the α1-receptor antagonist, prazosin, or the dopamine-receptor antagonist α-flupenthixol. The results demonstrate important conformational requirements for the interaction of catecholamines at presynaptic or postsynaptic α2-receptors, and suggest that a fully extended or anti-conformation of the noradrenaline molecule is involved in α2-receptor-agonist interaction.
Structure re-assignment of a metabolite of ampicillin and amoxycillin and epimerization of their penicilloic acids
Authors: Bird A E , Cutmore E A , Jennings K R , Marshall A C 
Published: April 2011

Abstract
Products formed in-vitro from ampicillin and amoxycillin penicilloates have been examined by high-performance liquid chromatography, ultraviolet and nuclear magnetic resonance spectroscopy and thiol group determination and were found to be the 5S epimers of the penicilloic acids. This is in contrast to a published claim that the corresponding penamaldic acids were formed by the treatment used.