bluuebunny/crossref_metadata_2025_split huggingface dataset:
[3H]Zacopride: Ligand for the Identification of 5-HT3 Recognition Sites
Authors: Barnes N M , Costall B , Naylor R J 
Published: April 2011

Abstract
[3H]Zacopride displayed saturable binding to homogenates of the rat entorhinal cortex as measured by the inclusion of the 5-HT3 receptor antagonist BRL 43694 in the incubation media. Scatchard analysis indicated a single high affinity binding site (KD 0.76 ± 0.08 nM, Bmax 77.5 ±6.5 fmol (mg protein)−1) with a Hill slope close to unity. Other 5-HT3 receptor antagonists (zacopride, ICS 205–930, GR38032F, GR65630, metoclopramide and cocaine) also competed for the binding site displacing 60% of the total [3H]zacopride binding. 5-HT and 2-methyl-5-HT also were competitive antagonists for [3H]zacopride binding whereas 5-HT1/5-HT2 agonists and antagonists, and agents acting on other neurotransmitter receptors had Ki values greater than 10−5 M. It is concluded that [3H]zacopride may prove a useful ligand for the study of 5-HT3 recognition sites.
Variations in the friction coefficients of tablet lubricants and relationship to their physicochemical properties
Authors: Baichwal A R , Augsburger L L 
Published: April 2011

Abstract
A previously described modified annular shear cell (MASC) has been used to measure the friction coefficients of some powdered tablet lubricants on a steel surface. Commonly used lubricants, as well as others belonging to the stearate group, differed in their friction coefficients at equivalent sample sizes and in the degree of their ability to reduce friction with increasing amounts when evaluated by the apparatus. In all comparisons, magnesium stearate had the lowest friction coefficient. Divalent salts of stearic acid appeared to be better than the other lubricants tested, and among themselves differed only in the extent of their ability to decrease friction. The lubricants also differed in their physical and chemical properties. On evaluation by stepwise regression analysis, such physical properties as projected surface area of lubricant particles, Martin’s diameter and bulk density accounted for most of the variation in friction coefficients of the lubricants rather than moisture content or melting point. It could therefore be suggested that particle size and/or surface area parameters be incorporated in product specifications to ensure reproducible functionality.
Dopamine receptor modulation of corticosterone secretion in neonatal and adult rats
Authors: Kitchen Ian , Kelly Mary , Turner Michelle 
Published: April 2011

Abstract
The effects of the dopamine agonist, pergolide, upon plasma corticosterone levels have been studied in 30 day old neonatal and adult rats. Dose-related elevations in corticosterone were observed at both ages and these elevations were blocked by the dopamine (D2) receptor antagonist spiperone. These studies demonstrate that dopaminergic neurochemical control of the hypothalamus-pituitary-adrenal axis exists in four week old rats in contrast to our previous studies which have shown opioid control to be absent at this age. It appears that neurochemical control of corticosterone is dissimilar in the neonate.
Influence of Lipophilicity and Chirality on the Selectivity of Ligands for β1- and β2-Adrenoceptors
Authors: Tayar Nabil El , Testa Bernard , van, de Waterbeemd Han , Carrupt Pierre-Alain , Kaumann Alberto J 
Published: April 2011

Abstract
Eudismic and QSAR analyses are reported for the β1- and β2-adrenoceptor affinities and β1-selectivity of 10 enantiomeric pairs of ligands with only N-isopropyl or N-t-butyl groups. For both receptors, the eudismic index (ratio of affinity) increases with the affinity of the eutomers. However, the affinity of the distomers for the β2-adrenoceptor is relatively high, suggesting additional hydrophobic interactions. This is confirmed by various correlations between affinities and lipophilicities, showing that the affinity for β2-adrenoceptors is slightly more dependent on lipophilicity than that for β1-adrenoceptors. As a result, the β1-selectivity of the investigated β1-adrenoceptor ligands is strongly and negatively correlated with their lipophilicity (r = −0.942).
Definition of the In-vivo Accumulation of [3H]spiperone in Brain using Haloperidol and Sulpiride to Determine Functional Dopamine Receptor Occupation
Authors: Chivers J K , Reavill C , Jenner P , Marsden C D 
Published: April 2011

Abstract
The in-vivo administration of [3H]spiperone caused an accumulation of radioactivity in the substantia nigra, tuberculum olfactorium, nucleus accumbens, striatum and frontal cortex when compared with cerebellar levels. Haloperidol (0.01–1.0 mg kg−1 i.p.) dose-dependently prevented the accumulation of [3H]spiperone in the substantia nigra, tuberculum olfactorium, striatum and nucleus accumbens. Sulpiride (10–160 mg kg−1 i.p.) dose-dependently prevented the accumulation of [3H]spiperone only in the substantia nigra. The effects of sulpiride on other areas were not consistent; there was a suggestion of a reduction in the accumulation of [3H]spiperone in tuberculum olfactorium and striatum, but not in nucleus accumbens. Neither haloperidol (0.01–1.0 mg kg−1 i.p.) nor sulpiride (10–160 mg kg−1 i.p.) caused displacement of [3H]spiperone from the frontal cortex. Both haloperidol (0.01–0.5 mg kg−1) and sulpiride (10–80 mg kg−1) increased striatal and mesolimbic HVA concentrations. Haloperidol potently blocked apomorphine-induced stereotypy but sulpiride was only effective at the highest dose employed. The functional effect produced by haloperidol correlated with its ability to define [3H]spiperone binding in-vivo to dopamine receptors in the substantia nigra, striatum and tuberculum olfactorium. In contrast, there was no correlation between functional effect of sulpiride and its ability to define [3H]spiperone binding in-vivo.
Intestinal absorption of cephalosporin antibiotics: correlation between intestinal absorption and brush-border membrane transport
Authors: Hori Ryohei , Okano Tomonobu , Kato Miyako , Maegawa Hitoshi , Inui Ken-Ichi 
Published: April 2011

Abstract
The absorption of seven cephalosporin antibiotics from the in-situ intestinal loop at pH 7.4 and their transport by brush-border membrane vesicles in the presence of an inward H+ gradient ([pH]i = 7.5, [pH]o = 6.0) were examined. A good correlation was found between the intestinal absorption rate and the initial uptake rate by brush-border membrane vesicles. The data suggest that the transport study using intestinal brush-border membrane vesicles is useful as a model system for the intestinal absorption of β-lactam antibiotics.
Effects of proenkephalin products on rat cardiac and vascular tissue in-vitro
Authors: Douglas H , Kitchen I 
Published: April 2011

Abstract
The cardiovascular effects of the four proenkephalin products [Metl-enkephalin (ME), [Leu]-enkephalin (LE), [Met]-enkephalyl-arg6phe7 (MEAP) and [Met]-enkephalyl-arg6-gly7-leu8 (MEAGL) have been studied on the isolated spontaneously beating rat atria and the perfused rat mesentery in-vitro. All four peptides (at concentrations up to 10−6M and in the presence of peptidase inhibitors) had no direct effect on atrial rate or contractility and did not alter responses to noradrenaline or field stimulation. In addition, the peptides had no effect on the perfusion pressure of the mesentery and did not alter vasoconstrictor responses to noradrenaline. The results show that proenkephalin products are without direct or modulating effects on atrial muscle or mesenteric vasculature of the rat, and suggest that there is no endogenous opioid control in these tissues.
Excretion and distribution of [14C]rhein and [14C]rhein anthrone in rat
Authors: de Witte P , Lemli J 
Published: April 2011

Abstract
After single intracaecal administration of [14C]rhein (25 mg kg−1) and [14C]rhein anthrone (20 mg kg−1) to rats, the summated recovery rates of 14C after five days were in urine 37(±8.3)% and 2.8(±0.4)% and in faeces 53(±9.5)% and 95 (±10.1)%, respectively. The clearance of radioactivity from the organs and tissues was almost complete within three days, with the exception of the kidney which exhibited pronounced retention of radioactivity even after five days (&lt;61% of 24 h values). Extracts of faeces from animals treated with [14C]rhein of [14C]rhein anthrone, revealed rhein as well as other radioactive substances, which chemically did not react as 1,8-dihydroxyanthraquinones.
The influence of concentration of two salicylate derivatives on rectal insulin absorption enhancement
Authors: Hauss David J , Ando Howard Y 
Published: April 2011

Abstract
3,5-Diiodosalicylate sodium (DIS), a highly lipophilic salicylate, was evaluated against 5-methoxysalicylate sodium (MS) as a potential adjuvant absorption promoter for rectal insulin delivery. Comparative blood glucose measurements were made using the two adjuvants under identical conditions as promoters of rectal insulin absorption in rats. Concentrations of DIS greater than and including 0.1 M produced an unexpected, progressive decrease in adjuvant activity as determined by a decline in observed hypoglycaemic response. This was not due to formation of an insulin-DIS complex. The adjuvant MS produced a classical, sigmoidal log-dose response curve. Possible reasons for the occurrence of the DIS optimum phenomenon are discussed as well as are the observed differences in adjuvant potency of these agents in a propylene glycol-containing vehicle.
New method for testing the absorbency of surgical dressings
Authors: Betts T J , Czarniak Petra A , Filippin Patricia 
Published: April 2011

Abstract
Absorbent cellulose dressings have been tested by immersion in a standard aqueous solution of picric acid followed by standard draining, elution of the picric acid, and measurement of the absorbance of the yellow colour at 355 nm. Six samples of gauze were graded by this procedure, and two considered unsatisfactory, despite all sinking in less than 10s. Filmated gauzes and unwoven dressings required greater dilution for the absorbance readings, reflecting their different structures.
A Consideration of the Range and Strength of Interparticle Forces in Coated Lactose Powder
Authors: Igwilo C , Pilpel N 
Published: April 2011

Abstract
A study has been made of the range and strength of interparticle forces in lactose powder coated with increasing concentrations of paraffins at different temperatures. Marked changes occurred in these forces as the paraffin content was altered and the temperature increased from − 10° to + 50°C. The strength and range of interparticle forces depended on the mechanical properties of the coating materials and the surface free energy of the coated powders.
Activities of Octopamine and Synephrine Stereoisomers on Octopaminergic Receptor Subtypes in Locust Skeletal Muscle
Authors: Evans Peter D , Thonoor C Mohan , Midgley John M 
Published: April 2011

Abstract
The activities of the (−) and (+)- forms of p-, m- and o- octopamine and p- and m- synephrine have been compared on the different subtypes of octopamine receptor present in the extensor-tibiae neuromuscular preparation from the locust hindleg. The rank order of potency of the (−)-forms on the OCTOPAMINE2A receptors was p-synephrine &gt; p-octopamine &gt; m-octopamine &gt; o-octopamine &gt; m-synephrine whilst the rank order of the (+)-forms was p-synephrine &gt; p-octopamine &gt; m-octopamine. (+)-m-Synephrine and (+)-o-octopamine had no effect on this class of receptor when tested up to a concentration of 10−3M. The rank order of potency of the (−)-forms on the OCTOPAMINE2B receptors was p-synephrine &gt; p-octopamine &gt; m-synephrine &gt; m-octopamine &gt; o-octopamine whilst the rank order of the (+)-forms was p-octopamine &gt; p-synephrine &gt; m-octopamine &gt; o-octopamine. (+)-m-Synephrine again had no effect up to a concentration of 10−3M. The rank order of potency of the (−)-forms ontheOCTOPAMINE1 receptors was p-synephrine &gt; p-octopamine &gt; m-synephrine &gt; m-octopamine &gt; o-octopamine, whilst the rank order of the (+)-forms was p-synephrine &gt; p-octopamine &gt; o-octopamine &gt; m-synephrine &gt; m-octopamine. In all cases the (−) enantiomers of all the structural isomers tested were more potent than the corresponding (+)-forms with isomeric activity ratios varying between 2 and 480. The activities of the octopamine and synephrine stereoisomers on the different octopamine receptor subtypes in the locust are compared with their published activities on the subtypes of mammalian α- and β-adrenoceptors.
Postnatal behavioural effects of maternal nicotine exposure in rats
Authors: Fung Y K 
Published: April 2011

Abstract
The effects of nicotine on locomotor activity have been studied in neonate rats exposed to nicotine (1.5 mg kg−1 day−1) throughout the gestational period. Both 14 day old male and female offspring demonstrated an increase in spontaneous locomotor activity when compared with saline-exposed controls. However, systemic administration of (+)-amphetamine was effective in attenuating the hyperactivity of these nicotine-exposed pups.
Stimulation of Gastric and Colonic Mucosal Eicosanoid Synthesis by Plantain Banana
Authors: Goel R K , Tavares I A , Bennett A 
Published: April 2011

Abstract
Extracts of plantain banana (Musa sapientum Linn var. paradisiaca) were studied on the accumulation of eicosanoids in incubates of human gastric and colonic mucosa. The ethanolic extract caused a concentration-dependent increase in the eicosanoid accumulation but the water extract was ineffective. Since all the eicosanoids studied tended to increase, banana may act by increasing the availability of arachidonate. In control tissues the accumulation of PGE and TXB2 in the incubates decreased with time while that of 6-keto-PGF1α increased (colon only, studied).
Biocompatibility of Wound Management Products: Standardization of and Determination of Cell Growth Rate in L929 Fibroblast Cultures
Authors: Turner Terence D , Spyratou Olga , Schmidt Richard J 
Published: April 2011

Abstract
To facilitate the development of a bioassay procedure by which the biocompatibilities of materials used in wound management may be assessed and compared, those environmental factors affecting cell growth in mouse L929 fibroblast cultures have been identified. Standardization of the initial cell number and frequency of change of medium resulted in the virtual elimination of variation of growth curves of L929 cells cultured in flasks of specified surface area. In addition, three methods for assessing fibroblast growth rate in the presence of alginate products used in wound management were evaluated. These were the haemacytometer counting chamber method, the Coulter counting method, and a liquid scintillation counting method. The first two methods determine the number of cells in a given volume of a cell suspension, whereas the third method determines the rate of synthesis of deoxyribonucleic acid (DNA), and hence cell growth, by measuring the incorporation of [3H]thymidine. The haemacytometer method had significant advantages over the other two procedures in providing both qualitative and quantitative data on culture morphology and cell growth response.
Transport of cephalosporin antibiotics in rat renal basolateral membranes
Authors: Takano Mikihisa , Okano Tomonobu , Inui Ken-Ichi , Hori Ryohei 
Published: April 2011

Abstract
Transport mechanisms of cephalosporin antibiotics in rat renal basolateral membranes have been studied in isolated membrane vesicles. Uptake of [14C]p-aminohippurate, a typical organic anion, by basolateral membrane vesicles was enhanced when membrane vesicles were preloaded with unlabelled p-aminohippur-ate (counter-transport). Cephalosporins such as cephradine, cephalexin, and cefazolin inhibited the counter-transport of [14C]p-aminohippurate, as did unlabelled p-aminohippurate and probenecid. In contrast, cephalexin did not affect the uptake of [3H]tetraeth-ylammonium, an organic cation, by basolateral membrane vesicles. These results suggest that most cephalosporins are transported via organic anion transport systems in rat renal basolateral membranes.
Vascular effects of propofol: smooth muscle relaxation in isolated veins and arteries
Authors: Bentley G N , Gent J P , Goodchild C S 
Published: April 2011

Abstract
Isolated hepatic portal veins and aorta taken from the rat were used to investigate the direct action of the intravenous anaesthetic propofol. This compound is known to produce a fall in blood pressure in man and animals and it has been suggested that the hypotension may result from a direct vasodilator action on the veins and arterioles. In our experiments propofol caused a dose related decrease of potassium-induced tone in both types of blood vessel. However, the concentrations required to produce this effect in the experiments on veins were significantly lower than those required to produce similar changes in the isolated artery preparation. We conclude that this direct action may contribute towards the hypotensive effects of propofol.
Vasocontractile action of daunorubicin
Authors: Wakabayashi Ichiro , Hatake Katsuhiko , Kakishita Eizo 
Published: April 2011

Abstract
Daunorubicin (35·5–142 μmol L−1) induced in rat aortic strips a contraction with slow onset and a gradual development of tension on which neither phentolamine nor bromophenacyl bromide pretreatment had an effect. The contraction was not altered by removal of the endothelium but it was suppressed in calcium-free solution or by preincubation with nifedipine. These results suggest that daunorubicin directly stimulates vascular smooth muscle and induces a contractile response which is mainly dependent upon extracellular calcium.
Effect of Auranofin on Ion Transport by Rat Small Intestine
Authors: Hardcastle Jacqueline , Hardcastle P T , Kelleher Debra K 
Published: April 2011

Abstract
Auranofin, applied either mucosally or serosally, increased the potential difference and short-circuit current generated by stripped sheets of rat mid-intestine in a concentration-dependent manner. In-vivo auranofin induced a net fluid secretion, suggesting that the rise in electrical activity represented a stimulation of anion secretion. Removal of chloride or addition of frusemide inhibited the auranofin-induced increase in short-circuit current, indicating that chloride was the anion involved and in the case of serosal auranofin this was confirmed by direct measurement of ion fluxes. The effects of both mucosal and serosal auranofin were calcium-dependent. The gold component of the auranofin molecule is probably responsible for its secretory actions as these were mimicked by chlorauric acid. The ability of auranofin to stimulate intestinal secretion may contribute to its diarrhoeagenic action.
Pharmacokinetics of 2′,3′-Dideoxycytidine in Rats: Application to Interspecies Scale-up
Authors: Ibrahim Safaa S , Boudinot F Douglas 
Published: April 2011

Abstract
The effects of dose on the pharmacokinetics of 2′,3′-dideoxycytidine (DDC), a potent inhibitor of HIV replication, have been studied in rats. DDC was administered intravenously at doses of 10, 50, 100 and 200 mg kg−1. Plasma and urine drug concentrations were determined by HPLC. Non-compartmental pharmacokinetic parameters were calculated by area/moment analysis. DDC plasma concentrations declined rapidly with a terminal half-life of 0·98 ± 0·18 h (mean± s.d.). No statistically significant differences were observed in pharmacokinetic parameters between the four doses. Total, renal and nonrenal clearance values were independent of dose and averaged 1·67 ± 0·24, 0·78 ± 0·11, and 0·89 ± 0·27 L h−1 kg−1, respectively. Approximately 50% of the dose was excreted unchanged in urine. Steady state volume of distribution was also independent of dose and averaged 1·2±0·21 L kg−1. Protein binding of DDC to rat serum proteins was independent of drug concentration with the fraction of drug bound averaging 0·45 ± 0·12. Thus, the disposition pattern of DDC in the rat is independent of the administered dose even at high doses. Significant interspecies correlations were found for total, renal and non-renal clearance and steady state volume of distribution. Interspecies scaling resulted in superimposable plasma DDC concentration-time profiles from four laboratory animal species and man. Thus, plasma DDC concentrations in humans can be predicted from pharmacokinetic parameters obtained in laboratory animals.
Characteristics of hydrogel as disintegrant in solid dose technology
Authors: Fassihi A R 
Published: April 2011

Abstract
A comparison between a hydrogel and the disintegrants Ac-di-sol, Avicel, maize starch and Primojel has been made using theophylline as the test drug in direct compression tableting. Results indicate that the disintegrant action of the hydrogel is comparable with that of the other disintegrants used, with no adverse effect on the dissolution of theophylline from these tablets as observed by thermal analysis study. The hydrogel’s physicomechanical performance in direct compression processing appears to have no undesirable effect on the physical properties of tablets. Scanning electron micrographs of freeze-etched samples of hydrogel demonstrated its internal structure. These results strongly suggest that hydrogels have great potential as efficient disintegrants in solid dosage formulations.
Incorporation of dyes into low density lipoprotein in the presence of non-ionic surfactants
Authors: Eley J G , Halbert G W , Florence A T 
Published: April 2011

Abstract
The interaction of low density lipoprotein (LDL) with two model dyes in the presence or absence of non-ionic surfactants has been studied. The water soluble dye, thymol blue, only weakly interacts with LDL to cause slight increases in particle size and the interaction can be reversed on column chromatography and dialysis. The oil-soluble dye sudan III reacts strongly with LDL to produce marked changes in particle size the complex formed being stable to dialysis and gel exclusion chromatography. These interactions are not affected by the presence of surfactants. The results indicate that even small quantities of lipophilic materials will easily partition into the particle, with or without the aid of surfactants and can have a marked effect on the measured size of the particle.
Salivatory effects induced by pirenzepine, atropine, metacine and hexamethonium in preganglionar chronically denervated human parotid gland
Authors: Levin S L , Kiselman I M 
Published: April 2011

Abstract
Both classical (atropine) and non-traditional (pirenzepine, metacine) antagonists of the muscarinic cholinoreceptors induce, rather than block, an intense and prolonged salivary response in chronically denervated human parotid glands and thus are capable of discriminating between neuronal and aneuronal receptors. Hexamethonium (benzohexonium) a ganglion-blocking agent (0·4 mL, 2·5%) completely inhibits this paradoxical salivation to atropine, benzilylcholine (metacine) and pirenzepine in the chronic preganglionically denervated human parotid gland. The authors discuss the essence of the revealed paradoxical phenomena.