bluuebunny/crossref_metadata_2025_split huggingface dataset:
Enhancement of Phosphatidylinositol Turnover and Cyclic Nucleotide Accumulation by Chronic Anethole Trithione Treatment in Rat Submaxillary Glands
Authors: Ukai Y , Taniguchi N , Yamazaki A , Kimura K 
Published: April 2011

Abstract
The effect of chronic treatment with anethole trithione (ANTT) on the phosphatidylinositol (PI) turnover and cyclic (c)AMP and cGMP accumulation in rat submaxillary glands (SMG) has been compared with the effect of chronic treatment with atropine and a Cholinesterase inhibitor, diisopropyl-fluorophosphate (dyflos, DFP). Experiments were performed 24, 48 and 24 h after the last dose of ANTT, atropine and dyflos, respectively. ANTT and atropine enhanced carbachol-stimulated [32P] incorporation into phosphatidic acid in the SMG slices, while dyflos showed no effect. Pilocarpine-stimulated in-vivo incorporation of [3H]myoinositol into inositol phosphates was significantly enhanced by ANTT, but not by atropine or by dyflos. Phospholipase C-dependent hydrolysis of phosphatidylinositol 4,5-bisphosphate was significantly enhanced by ANTT and atropine, but not by dyflos. Pilocarpine-stimulated in-vivo accumulation of cAMP and cGMP was enhanced by ANTT and atropine, but dyflos reduced cAMP accumulation without affecting cGMP accumulation. The enhancement of PI turnover and cyclic nucleotide accumulation seems to contribute to the development of supersensitivity of the salivary gland caused by chronic treatment with ANTT and atropine, while reduction of cAMP accumulation may be responsible for the subsensitivity caused by dyflos.
In-vivo (+)-[3H]Fenfluramine Binding to Rat Brain: Biochemical and Autoradiographic Studies
Authors: Gobbi Marco , Taddei Carlo , Mennlnl Tiziana 
Published: April 2011

Abstract
The in-vivo binding of (+)−[3H]fenfluramine to rat brain regions is saturable, as shown by the inhibition curves obtained by co-injecting increasing concentrations of unlabelled (+)−fenfluramine: at 2· 5 mg kg−1 the inhibition of total bound radioactivity was maximal in all regions. The regional distribution of (+)−[3H]fenfluramine specific binding sites (hypothalamus &gt; striatum = cortex &gt; brainstem &gt; hippocampus &gt; cerebellum) closely parallels the regional distribution of 5-hydroxytryptamine uptake. Computer-assisted quantitative autoradiography confirms these findings. The IC50 of (+)−fenfluramine for inhibition of its binding in-vivo is below 0·25 mg kg−1, compatible with the presence of high affinity sites. While the physiological role of (+)−[3H]fenfluramine binding sites in the brain, particularly in hypothalamic nuclei, is being investigated, it has been found that in-vivo labelling could also be obtained in the periphery, in lung and renal cortex. The possibility that this peripheral binding is due to the presence of blood platelets cannot be ruled out.
Effect of Histamine H2-Receptor Antagonists on Acute Inflammatory of the Rat Paw Oedema
Authors: Ezeamuzie Charles I , Umezurike Cyprain C 
Published: April 2011

Abstract
The effect of three histamine H2-antagonists, cimetidine, ranitidine, and loxtidine, on acute rat paw oedema induced by histamine, carrageenan or complete Freund’s adjuvant, have been examined. Administered intraperitoneally, all three antagonists inhibited histamine-induced paw oedema dose-dependently in the range 0·5–15 μmol kg−1. The highest dose of cimetidine produced an inhibition of 92% as against 38% with the same dose of mepyramine. Analysis of the concentration-effect curves produced IC50 values of 1·66, 5·12 and 12·30 μmol kg−1 for cimetidine, loxtidine, and ranitidine, respectively, on histamine-induced oedema. In carrageenan-induced inflammation 12·3 μmol kg−1 of each of the three drugs produced significant inhibition, whereas in adjuvant-induced inflammation, (acute phase), cimetidine was very active, loxtidine less so and ranitidine inactive. Thus the relative effectiveness of the antagonists (cimetidine &gt; loxitidine &gt; ranitidine) appears to differ from their known potency relationship (loxtidine &gt; ranitidine &gt; cimetidine) on H2-mediated effects. We conclude that H2-receptors are involved in the induction of rat paw oedema, especially those induced by histamine and carrageenan, but that their relative effectiveness appears atypical.
Effects of bovine serum albumin and recirculation rate on the uptake of propranolol by rat perfused lung
Authors: Iwamoto Kikuo , Watanabe Jun , Yonekawa Hina 
Published: April 2011

Abstract
Lungs isolated from 7-week-old rats were perfused with pH 7·4, oxygenated Krebs-Ringer bicarbonate buffer solution containing 2·5 μg mL−1 of propranolol and 3 to 5% BSA at the recirculation rate of 4 to 16 mL min−1, at 37°C for 60 min. The extent of propranolol metabolism after 60 min was less than 2·3% of the initial load under any in-vitro perfusion condition. Therefore, the amount disappearing from the perfusion medium was considered as being predominantly that taken up by tissue. Under all experimental conditions, perfusate drug level declined bi-exponentially with time. Apparent in-vitro pulmonary clearance of propranolol was not affected by the increase of BSA level from 3 to 5%. When the perfusate BSA level was fixed at 3%, the lowest recirculation rate (4 mL min−1) yielded the smallest clearance (about 0·15 mL min−1 g−1) but almost constant clearance value (about 0·40 mL min−1 g−1) was obtained at the rate ranging from 8 to 16 mL min−1. The tissue to medium concentration ratio of propranolol, after the perfusion with 3 to 5% BSA at the rate of 8 to 16 mL min−1, was approximately 35, whereas that with 3% BSA at 4 mL min−1 was reduced to about 20. The findings suggest evidence for flow-dependent in-vitro pulmonary clearance of propranolol.
Analgesic effects of 3-methoxybenzamide in rats
Authors: Sanders Robert , Dill Russell E , Dorris Roy L , Miller Edward G 
Published: April 2011

Abstract
The i.p. injection of 3-methoxybenzamide (3-MBA) in rats produces a dose-related elevation of the threshold for response to a painful stimulus. Metoclopramide, also a substituted benza-mide, has analgesic activity that is attenuated by bromocriptine, a dopamine receptor agonist, and by the narcotic antagonist, naloxone, suggesting involvement of dopamine and opiate receptors in the action of this drug. The involvement of these receptors in the analgesic action of 3-MBA has been examined using L -dopa and naloxone. Neither significantly altered the analgesic action. Although the results are preliminary, the analgesic action of 3-MBA would not seem to occur via opiate or dopamine receptors.
Marked increases in plasma catecholamine concentrations precede hypotension and bradycardia caused by 8-hydroxy-2-(di-n-propylamino) tetralin (8-OH-DPAT) in conscious rats
Authors: Bagdy Gyoroy , Szemeredi Katalin , Murphy Dennis L 
Published: April 2011

Abstract
Plasma noradrenaline and adrenaline responses to 8-hydroxy-2-(di-n-propylamino)-tetralin (8-OH-DPAT), a selective putative 5-HT1A receptor agonist, have been studied in conscious, freely moving rats. Intravenously administered 8-OH-DPAT caused dose-related and sustained increases in plasma noradrenaline (2-fold) and adrenaline (11-fold) concentrations. Neither metergoline pretreatment (0·5 mg kg−1 i.v.) nor splanchnicectomy had any effect on the noradrenaline and adrenaline elevation caused by 8-OH-DPAT (250 μg kg−1 i.v.). The catecholamine responses peaked early but were still present during nadirs in blood pressure and heart rate. The discrepancy between plasma catecholamine and cardiovascular changes raises further questions about the mechanism of action of 8-OH-DPAT and supports other evidence suggesting a role for vagus stimulation in the cardiovascular effects caused by this drug.
The availability of diltiazem: A study on the sorption by intravenous delivery systems and on the stability of the drug
Authors: de Vroe C , de Muynck C , Remon J P , Scheldewaert R , Colardyn F 
Published: April 2011

Abstract
The stability and the sorption by intravenous delivery systems of the calcium antagonist diltiazem dissolved into either 5% dextrose or 0·9% sodium chloride solutions have been investigated, under conditions simulating current clinical practice. Static experiments showed an excellent stability and no sorption after 48 h. Dynamic experiments, at a perfusion rate of 20 mg h−1, showed no sorption of the drug by infusion fluid containers, burettes or administration sets. For end-line filters a temporary decrease of the recovered amount of diltiazem was observed but only with the 0·9% NaCl solution. It is concluded that the stability and the sorption of diltiazem offers no problem with regard to clinical efficacy.
Diamorphine stability in aqueous solution for subcutaneous infusion
Authors: Omar O A , Hoskin P J , Johnston A , Hanks G W , Turner P 
Published: April 2011

Abstract
The influence of temperature and concentration on diamorphine stability during storage over 8 weeks has been investigated. Ampoules containing diamorphine hydrochloride in concentrations from 0·98–250 mg mL−1 have been stored at −20, 4, 21 and 37°C for 8 weeks. Their content of diamorphine, 6-monoacetylmorphine and morphine, on measurement by high performance liquid chromatography after 1, 2, 4, 6 and 8 weeks storage changed to slow degradation of diamorphine at all concentrations at temperatures of 4°C and above. This was accompanied by a corresponding increase in 6-monoacetylmorphine and morphine. There was an associated fall in pH and development of a strong odour characteristic of acetic acid. Precipitation and a white turbidity seen in solutions of 15·6 mg mL and above, appeared after 2 weeks incubation.
Evidence for α1-adrenoceptor subtype predominance in the rat seminal vesicle
Authors: Adenekan O O 
Published: April 2011

Abstract
Noradrenaline (0·6–19 μM and phenylephrine (2–130 μM induced contractions in the rat seminal vesicle that were competitively antagonized by the α1-adrenoceptor-selective antagonist corynanthine (120–920 nM). Yohimbine (60–450 nM), an α2 adrenoceptor-selective antagonist, produced a non-competitive antagonism of noradrenaline responses, suggesting that the responses were not α2-adrenoceptor mediated. It is concluded that the rat seminal vesicle has a predominance of α1-adrenoceptors.
Contribution of the tissue angiotensin converting enzyme to the antihypertensive effect of altiopril calcium (MC-838) in spontaneously hypertensive rats
Authors: Kamei Kenshi , Shiraki Yasuyuki , Koga Takaki , Sakai Kazushige 
Published: April 2011

Abstract
The effect of a new orally active angiotensin converting enzyme (ACE) inhibitor, calcium (—)-N-[(S)-3–[(N-cyclohexylcarbonyl-D -alanyl)thio]-2-methylpropionyl]-L -prolinate (MC-838, altiopril calcium), on systemic blood pressure (SBP) and tissue ACE activity has been examined in conscious spontaneously hypertensive rats (SHRs). MC-838 (3 mg kg−1) given orally to SHRs elicited a long-lasting hypotension lasting over 24 h. With the development of the hypotension, MC-838 significantly reduced ACE activity in the lung, kidney and aorta, but not in the brain and heart. Suppression of plasma ACE and rise of plasma renin activity occurred only transiently at an earlier stage.
Effects of indeloxazine hydrochloride on cognitive disturbance in cycloheximide-treated mice
Authors: Yamamoto M , Shimizu M 
Published: April 2011

Abstract
The effects of indeloxazine hydrochloride [(±)-2-[(inden-7-yloxy)methyl]morpholine hydrochloride] on cognitive disturbance in mice subjected to cycloheximide have been examined. Indeloxazine ameliorated cycloheximide-induced amnesia in mice, indicating a facilitatory effect of this drug on cerebral functions. Piracetam, Ca-hopantenate, dihydroergotoxine and viloxazine did not show significant effect on the amnesia. These results suggest that indeloxazine possesses a wider pharmacological profile than Piracetam, Ca-hopantenate, dihydroergotoxine and viloxazine in anti-amnesic activities.
Quantitative Design for Photostabilization of Nifedipine by using Titanium Dioxide and/or Tartrazine as Colourants in Model Film Coating Systems
Authors: Teraoka Reiko , Matsuda Yoshihisa , Sugimoto Isao 
Published: April 2011

Abstract
The photostabilization of nifedipine by using film coating has been investigated in model systems in which a drug sample, dispersed on a glass plate, was covered with a free film and exposed to intensive light of mercury vapour lamp. The light transmission properties of films containing titanium dioxide or tartrazine alone as colourant were not always satisfactory. The tartrazine system exhibited superior light transmission properties to the titanium dioxide system at all additive concentrations. However, in combination both colourants gave much better light protection than did the colourants separately.
The film-coated drug degraded following apparent first-order kinetics. The degradation rate constant decreased as both colourant concentration and film thickness increased; thus photostabilization was almost completely achieved by applying a film (thickness: 60 μm) of the binary mixture system containing only 0·7% of each of these colourants. The protective effectiveness of a film could be quantitatively evaluated by plotting the degradation rate constant against CL value of film formulation (C: concentration of colourant; L: film thickness). The degradation rate constant showed a good linear correlation with the average percent transmittance of a film in the wavelength range relating to the photolytic degradation of the drug. The average percent transmittance was thus proved to be an important and useful parameter for estimating the photostability of film-coated drugs.
Non-specific Hyperreactivity to Pharmacological Stimuli in Tracheal and Lung Parenchymal Strips of Actively Sensitized Guinea-pigs
Authors: Ortiz J L , Cortijo J , Sanz C , Perpiñá M , Iriarte C F , Sarría B , Esplugues J , Morcillo E J 
Published: April 2011

Abstract
The responsiveness of tracheal and lung parenchymal strips isolated from actively sensitized guinea-pigs to CaCl2 (in K+-depolarized tissue), KCl, acetylcholine and histamine was compared with that of strips from unsensitized animals. The concentration-response curves to the mentioned agonists exhibited, in the sensitized group, a left upward displacement (greater maximal effect, lesser effective concentration 50% and a steeper slope) compared with those obtained in the unsensitized group. These results indicate the existence of a non-specific increase in responsiveness in the airway smooth muscle from sensitized animals.
Isolation and Characterization of Pelamis platurus (Yellow-bellied Sea Snake) Postsynaptic Isoneurotoxin
Authors: Mori Nobuhiro , Ishizaki Hiroyuki , Tu Anthony T 
Published: April 2011

Abstract
Pelamis platurus (yellow-bellied sea snake) venom contains several neurotoxins, the major toxin, which is most toxic, and two other isotoxins. The second most toxic neurotoxin (Pelamis toxin b) was isolated and characterized. It contains 60 amino acid residues with only one residue difference from the major toxin, Pelamis toxin a. The difference is at the tenth amino acid residue from the acid terminal. The isoelectric point of toxin b is 8·7. Raman spectroscopic examination of toxin b indicates that the toxin contains a considerable amount of antiparallel β-structure, β-turn, and random coil without α-helix as the amide I band appears at 1673 cm−1 and the amide III band at 1246 cm−1. Circular dichroic studies also indicate a typical β-sheet structure. The Pelamis toxin b is a typical postsynaptic neurotoxin as it binds to the acetylcholine receptor competitively with a well known toxin, α-bungarotoxin. The LD50 of toxin b is 0·185 μg g−1 in mice by intravenous injection, indicating high toxicity of a postsynaptic neurotoxin.
Effects of K+-Canrenoate on the Development of DOCA-salt Hypertension
Authors: Vargas F , Haro J M , Jodar E , Soler A , Del Rio C Garcia 
Published: April 2011

Abstract
The effects of K+-canrenoate, a digoxin antagonist, on the role of digoxin-like factor in the development of DOCA-salt hypertension has been examined. DOCA-salt rats treated with 66 mg kg−1 day−1 of K+-canrenoate (s.c.) presented a lower increase in blood pressure (P&lt;0·01), less cardiac hypertrophy (p&lt;0·05) and hypokalaemia (P&lt;0·05) than non-treated DOCA-salt rats. K+-canrenoate treatment did not lead to significant changes in urinary volume, Na+ and K+ urinary excretion or suppression of plasma renin activity in DOCA-salt rats. None of the parameters were significantly different between uninephrectomized-salt rats treated or non-treated with K+-canrenoate. These data suggest a role for digoxin-like factor in DOCA-salt hypertension. However, the non-normalization of blood pressure observed in K+-canrenoate DOCA-salt treated rats indicates that other factors contribute to the initiating mechanisms in this type of hypertension. Moreover, these data suggest that digoxin-like factor plays no role in the suppression of plasma renin activity induced by DOCA and salt treatment.
3-Amino-1-hydroxypropylidene-1,1-diphosphonate (APD): a novel enhancer of rectal cefoxitin absorption in rats
Authors: van Hoogdalem E J , Wackwitz A T E , de Boer A G , Breimer D D 
Published: April 2011

Abstract
The promoting action of the calcium chelating compound EDTA on intestinal drug absorption is supposed to be based on Ca2+ depletion, inducing widening of tight junctions. The aim of the present study was to evaluate the effects of the calcium-binding agent 3-amino-1-hydroxypropylidene-1,1-diphosphonate disodium salt (APD) on rectal cefoxitin absorption in rats. The extent of rectal cefoxitin absorption was enhanced by 0·5 to 6% w/v of APD, on rectal infusion as well as on bolus delivery, the latter regimen tending to result in lower bioavailabilities. A maximal cefoxitin bioavailability of 85 ± 10% was achieved by infusion with 4% w/v of APD, compared with 14 ± 12% without APD.
L-Ascorbic acid produces hypoglycaemia and hyperinsulinaemia in anaesthetized rats
Authors: Cheng J T , Hsieh-Chen S C , Tsai C L 
Published: April 2011

Abstract
L-Ascorbic acid (Vitamin C) produced a marked reduction in the blood glucose concentration following intravenous injection (20–100 mg kg−1) to anaesthetized rats. This hypoglycaemic effect was accompanied by an increase in plasma insulin concentration. D-ascorbic acid produced a similar hypoglycaemic effect.
Serum glucose and insulin levels in normotensive (WKY) and spontaneously hypertensive (SH) rats during and after the cessation of continuous (10 day) Clonidine infusion
Authors: Lewis S J , Dunlop M , Jarrott B 
Published: April 2011

Abstract
The concentrations of glucose were elevated whereas those of insulin were decreased in the sera of normotensive Wistar-Kyoto (WKY) and spontaneously hypertensive (SH) rats on day 10 of a continuous subcutaneous infusion of Clonidine (10 μg kg−1 h−1 for 10 days). Fifteen to 18 h after cessation of infusion, the glucose levels of both strains had fallen to below those of the respective controls whereas the insulin levels remained suppressed. As such the hypoglycaemia may be related to the general increase in metabolic requirements associated with the post-infusion ‘withdrawal syndrome’.
Preparation of Drug-Diluent Hybrid Powders by Dry Processing
Authors: Ishizaka Takafumi , Honda Hirotaka , Kikuchi Yuji , Ono Kenji , Katano Toshio , Koishi Masumi 
Published: April 2011

Abstract
New hybrid powders have been produced by the dry processing of six drugs (oxyphenbutazone, prednisolone, theophylline, indomethacin, phenacetin and aspirin), with potato starch used as a core material, by means of an electric mortar and a powder suface reforming system designed to produce hybrid powders. The hybrid powders obtained immediately after production differed in their structure from interactive mixtures. With the hybrid powders the drug was spread on the surface of the core particle by friction and collision that occurred in the dry process, but with interactive mixtures the drug simply adhered as intact particles to the surface of diluent particles. Scanning electron microscopy and powder X-ray diffractometry indicated that the mechanochemical phenomenon was essential for the production of the hybrid powders. With time, a shape change in the adhering drug was observed as a relaxation process took place, with recrystallization resulting from the release of accumulated energy. The change with time might depend upon the method of producing powders and the physical properties of the drug used, e.g. the smooth layer of indomethacin produced by the powder surface reforming system reverted to fine particles tightly adhering to the starch surface, though no change was observed with prednisolone.
Dissolution of Theophylline from Film-coated Slow Release Mini-tablets in Various Dissolution Media
Authors: Fassihi A R , Munday D L 
Published: April 2011

Abstract
The dissolution of an experimental formulation of film-coated slow release theophylline mini-tablets has been investigated using the USP paddle apparatus in test media at pH 1·2 (hydrochloric acid), pH 5·4 and 7·4 (phosphate buffers) at 37°C. Monitoring of in-vitro theophylline release over 12 h, under identical hydrodynamic conditions, showed that the dissolution rate at pH 1·2 is substantially greater (95% of total drug content released in &lt; 10 h) than that in phosphate buffers. The maximum release after 12 h was approximately 20 and 30% of total drug content of the tablet at pH 5·4 and 7·4, respectively. However, in-vivo bioavailability after oral administration of tablets to rabbits corresponded to over 95% of total drug, compared with the same dose administered intravenously. The retarded drug release during in-vitro dissolution in phosphate buffer was attributed to a possible interaction of phosphate ions with theophylline molecules at the tablet core-coat interface. These findings indicate that both rate and extent of theophylline release from the slow release coated mini-tablets are highly sensitive to phosphate buffers. The data also emphasize the usefulness of an animal model for assessment of in-vivo drug release and subsequent absorption, during the development of modified release dosage forms.
In-vitro Bioassays for Cholecystokinin
Authors: Sjödin Lars , Nederman Thore , Olsson Per Anders , Viitanen Eila 
Published: April 2011

Abstract
Two in-vitro methods for the bioassay of cholecystokinin (CCK) are described. They should be useful for determinations of potencies of pharmaceutical formulations of CCK. Both are based on the hormone’s ability to stimulate exocrine pancreas. The stimulatory effect on 45Ca efflux from preloaded suspended acinar cells or on release of amylase from pancreatic acini from the guinea-pig has been recorded. The assay based on stimulation of 45Ca outflux is more specific and precise than the method using measurements of amylase secretion. Therefore, the calcium assay was further validated against the conventional guinea-pig gall-bladder contraction assay. Both methods gave similar potency readings but the results from the in-vitro assay were more precise.
Human liver and plasma aspirin esterase
Authors: Williams Faith M , Mutch E M , Nicholson E , Wynne H , Wright P , Lambert D , Rawlins M D 
Published: April 2011

Abstract
The plasma, in addition to the liver, is a major site of hydrolysis of aspirin. Human plasma and liver aspirin esterase activities in samples from a group of patients varied over a two fold range and there was a significant correlation between individual plasma and liver activities. Human liver aspirin esterase was present in the cytosolic and microsomal fractions. Cytosolic and microsomal enzymes had different activities and apparent affinities for aspirin.