bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effects of St−587 on the α-adrenoceptors in the Bisected Rat Vas Deferens
Authors: Badia A , Sallés J 
Published: April 2011

Abstract
The effects of the α-adrenoceptor agonist St−587 have been studied on the twitch responses induced by field stimulation in the prostatic portion of rat vas deferens. Moreover the drug’s influence on the unstimulated prostatic and epididymal halves of rat vas deferens has also been determined. Alone and after addition of yohimbine (0·3 μM) it enhanced in a concentration-dependent manner the twitch responses in the prostatic half. Prazosin competitively antagonized (pA2 = 8·41 · 0·03) this effect. The enhancing effect of St−587 was not reduced in reserpinized animals. These results suggest that post-synaptic α1-adrenoceptors are involved in the potentiation of twitch responses induced by St−587. When α1-adrenoceptors were blocked by prazosin (0·1 μM), St−587 partially inhibited the twitch responses of the prostatic portion of rat vas deferens (Emax=49·5 ± 3·5%). Yohimbine completely reversed the inhibitory effects of both St-587 and Clonidine. Furthermore St−587 antagonized the inhibitory effects of Clonidine on twitch responses. Thus it appears that St−587 also behaves as a partial agonist of presynaptic α2-adrenoceptors in this portion of rat vas deferens, but it did not induce contractions in the unstimulated prostatic half of the vas deferens. However, it competitively antagonized the α1-adrenoceptor agonist phenylephrine by acting as an antagonist of prostatic postsynaptic α1 adrenoceptors. These α1-adrenoceptors are probably different from those that mediate the twitch enhancing response to St−587 in that portion. On the other hand, St−587 was a partial agonist of α1-adrenoceptors in the epididymal half. These results suggest that a different efficiency of stimulus-response mechanism is operating after postsynaptic α1-adrenoceptor activation in each one of the unstimulated portions of rat vas deferens.
Carbamoylated Enzyme Reversal as a Means of Predicting Pyridostigmine Protection Against Soman
Authors: Ellin Robert I , Kaminskis Andris 
Published: April 2011

Abstract
The inhibition of human and mammalian red blood cell (RBC) Cholinesterase (AChE) in whole blood in the presence of added pyridostigmine has been examined. After the addition of pyridostigmine to animal and human blood, red cells were separated from plasma at varying intervals and their enzyme activity measured. An apparent rate constant (ke) was derived for the reaction sequence in which carbamate is released from AChE inhibited by pyridostigmine. The constant is a complex of the rates of decarbamoylation and reinhibition of AChE in the blood sample. Rate constants were also determined for the spontaneous reactivation (ks) of carbamoylated AChE in the species studied. Values of ks were greater than ke in corresponding species but varied little between species. Pretreatment of animals with pyridostigmine is known to be an effective therapy against organophosphorus compounds, including soman. The ranking of ke values in mammalian blood was the same as that for the protection against soman in animals: monkey&gt;guinea-pig&gt;rabbit&gt;rat (ke = 0·15, 0·07, 0·05, 0·02 h−1, respectively). Since ke for human blood (0·20 h−1) was greater than that of monkey, pyridostigmine pretreatment would be expected to be an effective prophylaxis for soman in humans.
The effect of repeated treatment with antidepressant drugs on the thyrotropin-releasing hormone (TRH)-induced hyperthermia in mice
Authors: Przegaliński Edmund , Baran Leokadia , Siwanowicz Joanna 
Published: April 2011

Abstract
The effect of acute (single dose) or repeated (twice daily, for 14 days) administration of 10 mg kg−1 p.o. of Imipramine, amitriptyline, Citalopram or mianserin has been examined on the hyperthermia induced by thyrotropin-releasing hormone (TRH) (40 mg kg−1 i.p., 2, or 2 and 72 h after single or last dose of antidepressants, respectively) in mice. Both imipramine and amitriptyline, given repeatedly, potentiated the TRH response, though the effect was observed 2 but not 72 h after the last dose of those drugs. Potentiation was also found after the single dose of imipramine or amitriptyline. On the other hand, Citalopram and mianserin, administered either acutely or repeatedly, did not affect the TRH-induced hyperthermia.
Bromocriptine-induced decrease in blood pressure in conscious spontaneously hypertensive rats: Evidence for a peripheral site of action
Authors: van den Buuse M , Lambrechts A C 
Published: April 2011

Abstract
The aim of the study was to discover whether the dopamine agonist bromocriptine has a central or peripheral site of action on blood pressure. An intraperitoneal injection of bromocriptine (0·5 mg kg−1) induced a long-lasting decrease in blood pressure in conscious spontaneously hypertensive rats (SHR). This effect was blocked by peripheral pretreatment with haloperidol or domperidone, but not by central treatment with haloperidol. A central injection of bromocriptine had only minor effects on blood pressure. These results suggest that primarily peripheral, rather than central, mechanisms are involved in the hypotensive effects of bromocriptine.
Absence of [3H]SCH 23390 binding sites in the rat adrenal gland
Authors: Zdilar D , Lacković Z 
Published: April 2011

Abstract
The binding of D2-dopamine receptor ligand [3H]spiperone and selective D1-ligand [3H]SCH 23390 to the rat adrenal gland and striatum has been compared. [3H]Spiperone showed specific binding in both tissues revealing a Bmax of 887 fmol mg−1 protein and KD of 0·38 nM, and B of 34 fmol mg−1 protein and KD of 0·66 nM in the striatum and adrenal gland, respectively. On the other hand, [3H]SCH 23390 showed a specific binding to the striatal tissue with Bmax of 747 fmol mg−1 protein and KD of 0·70 nM, while in the adrenal tissue no specific binding was observed. These results apparently indicated only D2-dopamine receptor binding sites being present in the rat adrenal gland.
Bioavailability of isradipine in young and old rats: Effect of mode of administration
Authors: Tse F L S , Jaffe J M , Hassell A E , Schran H F 
Published: April 2011

Abstract
The bioavailability of isradipine has been examined in 7-and 52-week-old rats after oral (12·5 mg kg−1) or intravenous (2·5 mg kg−1) doses as a solution and administration of various doses (1·8–85·5 mg kg−1) in the diet. Serial plasma samples were obtained from each rat and the drug concentration was determined by radioimmunoassay. Absorption from the dose given by gavage was rapid but when administered in a drug-diet mixture, isradipine appeared in the plasma slowly and in a manner reflecting the feeding pattern. Its absolute bioavailability from the drug-diet mixture averaged 3% over the dose range tested. By gavage its bioavailability was enhanced to 5% of dose with peak plasma values approximately 7 times higher than from a comparable dose in the diet. The low oral bioavailability of isradipine in the rat was most likely due to extensive first-pass metabolism. The decline in plasma concentrations was biexponential, with a mean terminal half-life of 3·6–3·7 h after oral or intravenous dosing. The pharmacokinetic characteristics of isradipine examined were independent of the age of the rat, except that its volume of distribution decreased with age. The older rats also showed a greater inter-animal variability in isradipine bioavailability from the drug-diet mixture.
Purification of Pluronic F-68 for perfluorochemical emulsification
Authors: Bentley P K , Davis S S , Johnson O L , Lowe K C , Washington C 
Published: April 2011

Abstract
A novel technique for purification of Pluronic F-68 has been developed involving passage through a silica-Amberlite resin column. Impurities present in commercial grade Pluronic could be readily removed, as confirmed by analysis of absorption and fluorescence emission bands. Intravenous injection of a 4% (w/v) unpurified Pluronic solution in male rats increased mean liver weight by 14% (P&lt;0·05) after 24 h and increased spleen weight in female rats by 29% (P&lt;0·01) after 7 days. No corresponding tissue weight changes occurred following injection of purified Pluronic solution. Haematocrit and red cell counts were also unchanged throughout. We propose that the use of purified Pluronic for perfluorochemical emulsification may reduce previously reported side-effects.
Permeability of Cellulose Polymers: Water Vapour Transmission Rates
Authors: Sprockel O L , Prapaitrakul W , Shivanand P 
Published: April 2011

Abstract
The water vapour transmission rates (WVTR) through solvent cast polymer films prepared from cellulose acetate, cellulose acetate propionate, and cellulose acetate butyrate have been determined. They were influenced by the relative humidity, the substituent type and the extent of substitution. Increasing the relative humidity from 32 to 90% increased the WVTR 3 to 5 times depending on the polymer used. The WVTR increased in the order of butyrate &lt; propionate &lt; acetate. An increase in the extent of substitution with acetyl and/or butyryl groups resulted in an exponential decline in the WVTR.
Decrease in Penbutolol Central Response as a Cause of Changes in its Serum Protein Binding
Authors: Jordá R Martínez , Aguirre C , Calvo R , Rodríguez-Sasiaín J M , Erill S 
Published: April 2011

Abstract
Penbutolol is a β-adrenoceptor antagonist that is extensively bound to α1-acid glycoprotein (α1-AGP), a protein that increases in inflammatory diseases thereby binding more drug in such conditions. Changes in serum binding can lead to modifications in the pharmacokinetics and pharmacodynamics of a drug, therefore, the central effect (as the anticonvulsant response) and brain uptake of penbutolol given intravenously to mice with experimental inflammation have been measured. A significant decrease of the central effect of penbutolol and its brain uptake was seen in diseased when compared with control animals (P &lt; 0.01). A parallel decrease in free fraction of penbutolol in diseased vs normal animals was detected. These results suggest that there is an increase in serum binding of basic drugs related to increments in α1-AGP concentration, which reduces their central pharmacological effect.
Increased proliferation of phytohaemagglutinin (PHA)-stimulated human leucocytes after 8-methoxypsoralen treatment
Authors: Gawron A , Górski G , Glowniak K 
Published: April 2011

Abstract
The effect of 8-methoxypsoralen on human blood mono-nuclear cells cultured in darkness has been examined. 8-Methoxypsoralen (1 μg mL−1, 4.6 μM) added to (phytohaemagglutinin-stimulated cells induced a two-fold increase in the number of mitoses. The number of blastic cells also increased. There was no effect on the formation of micronuclei and there was no chromosomal breakage.
Enhancing effect of combining two pyrrolidone vehicles on transdermal drug delivery
Authors: Sasaki Hitoshi , Kojima Masaki , Nakamura Junzo , Shibasaki Juichiro 
Published: April 2011

Abstract
The enhancing effect of combining 1-methyl-2-pyrrolidone (MP) and 1-lauryl-2-pyrrolidone (LP) as the vehicles for transdermal penetration of phenolsulphonphthalein (phenol red) has been investigated by using an in-vitro technique with excised rat skin. LP had a higher enhancing effect on the penetration of phenol red than MP, but there was a long lag time before steady-state penetration was attained. A potent effect with a shorter lag time was obtained when MP and LP were used together. This potentiation was maintained when the concentration of MP was decreased by 95%. The combined vehicle also enhanced the skin accumulation of phenol red. MP promoted the rapid penetration of LP into the skin and potentiated the enhancing effect of LP on the penetration of phenol red and thereby shortened the lag time. The combined vehicle also enhanced the penetration of the hydrophilic anticancer agent, 5-fluorouracil.
Circadian phase dependent acute toxicity and pharmacokinetics of etidocaine in serum and brain of mice
Authors: Bruguerolle Bernard , Prat Marin 
Published: April 2011

Abstract
The aim of this study was to investigate the possible influence of the time of administration on etidocaine acute toxicity and kinetics in mice. Different groups of adult male NMRI mice maintained under controlled environmental conditions (lights on 06.00–18.00) were injected at one of the following times: 10.00, 16.00,19.00,22.00,01.00 and 04.00 h with four doses of etidocaine at each time point to establish the acute toxicity (LD 50). To assess chronokinetics, a single 40 mg kg−1 i.p. dose of etidocaine was given to adult male NMRI mice at four fixed times: 10.00,16.00,22.00 and 04.00 h. Etidocaine serum levels were determined by GLC. The data showed significant 24 h variations of the Cmax only (highest value = 9.64 ± 1.31 μg mL−1 at 10.00 P &lt; 0.05; amplitude, (maximum-minimum) mean × 100 = 84%) Vd, (amplitude = 59.7%), α and β phase elimination half-lives (amplitude = 52 and 35%, respectively), clearance (amplitude = 23%) and AUC°8 (amplitude = 22%) were not found to be significantly time dependent. Etidocaine kinetics in brain were determined similarly; a significant temporal variation was found for the elimination half life (amplitude, 161.9%) and AUC (amplitude, 133.2%) but not for Cmax. These data demonstrate a temporal pattern of etidocaine kinetics similar to those reported previously for other local anaesthetic agents, bupivacaine and mepivacaine. The temporal changes in etidocaine induced acute toxicity may result in part from its chronokinetic changes.
Hyperoxia and salicylate metabolism in rats
Authors: O'Connell Martin J , Webster Nigel R 
Published: April 2011

Abstract
Following the administration of aspirin to rats by gavage, both 2,3- and 2,5-dihydroxybenzoate appeared in the plasma. The concentration of the 2,3-dihydroxybenzoate was significantly higher in animals exposed to 100% O2 for 60 h than in air breathing controls. These data are evidence that increased salicylate hydroxylation is associated with oxidative stress.
Correlation of phenol sulphotransferase activities in the liver and platelets of rat
Authors: Nakamura Junko , Mizuma Takashi , Hayashi Masahiro , Awazu Shoji 
Published: April 2011

Abstract
Phenol sulphotransferase (PST) activity in rat platelet cytosol for p-nitrophenol (PNP) sulphation was found to have a similar dependence on PNP concentration and thermostability to that in rat liver cytosol. The activities of PST isoenzyme for the sulphation in the μM range of PNP in rat platelets and rat liver were significantly correlated. Thus, measurement of PST activity in platelets could be a useful and practical method for predicting this activity in liver.
Morphine and opioid peptides selectively inhibit the non-cholinergically mediated neurogenic contraction of guinea-pig isolated bronchial muscle
Authors: Kamikawa Yuichiro , Shimo Yasuo 
Published: April 2011

Abstract
The experiments examine the actions of morphine and opioid peptides on the responses evoked by electrical field stimulation or by acetylcholine (ACh) and substance P (SP) in guinea-pig bronchial strip chain. Electrical field stimulation evoked a biphasic contraction, consisting of a cholinergically mediated fast contraction followed by a non-cholinergically mediated slow contraction. Morphine and opioid peptides caused a concentration-dependent inhibition in the height of the non-cholinergic contraction. The order of inhibitory activity was BW443C &gt; dynorphin &gt; morphine &gt; β-endorphin &gt; leucine-enkephalin &gt; methionine-enkephalin. Cholinergically mediated contractions were less potently inhibited by these opioids. Submaximal contractions of bronchial muscle evoked by exogenous ACh (2 μM) or SP (02 μM) were not inhibited by morphine (100 μM) or opioid peptides (3–10 μM), rather, they were augmented. The results indicate that in guinea-pig isolated bronchial muscle, morphine and opioid peptides can selectively inhibit excitatory non-cholinergic neurotransmission via prejunctional opioid receptors.
Evidence for more than One Binding Site for Sulfonylureas in Insulin-secreting Cells
Authors: Verspohl E J , Ammon H P T , Mark M 
Published: April 2011

Abstract
Specific binding of both [3H]glibenclamide and [3H]gliquidone has been observed in a particulate fraction of insulin-secreting rat tumour (RIN m5F) cells. The binding of both the labels was time-dependent, of high affinity (including a low affinity binding site), saturable and reversible. The rank order of inhibition of [3H]glibenclamide binding was glibenclamide &gt; gliquidone &gt; AG-EE 388 = AG-EE 86 = AG-EE 319 &gt; AG-EE 436 (AG coded drugs are benzoic acid derivatives which lack the sulfonylurea moiety of sulfonylureas). The KdS of high affinity binding for glibenclamide and gliquidone were 0.08 and 1.3 nM, respectively. When [3H]gliquidone was used as the labelled compound this rank order of binding and the affinities of drugs were different, e.g. glibenclamide was less potent than gliquidone. The Kd values of high affinity binding to the [3H]gliquidone binding site were 810 and 79 nM with respect to glibenclamide and gliquidone. The binding site labelled by [3H]gliquidone, in contrast to that labelled by [3H]glibenclamide, was not able to discriminate between the two enantiomers AG-EE 319 and AG-EE 436. The data indicate that there are different binding sites for glibenclamide and gliquidone in RIN m5F cells. In extension to data of other groups it is speculated that there exists more than one specific binding site for sulfonylureas and other related compounds, e.g. benzoic acid derivatives and that sulfonylureas behave differently not only in quantitative but in qualitative terms as well.
Inhibitory Effect of HSR-6071, A New Anti-allergic Agent, on Experimental Asthma in Rats and Guinea-pigs
Authors: Makino Eiichi , Ohashi Tetsuo , Takahashi Hiromi , Kato Hideo , Ito Yasuo , Nagai Hiroichi , Koda Akihide , Azuma Hiroshi 
Published: April 2011

Abstract
The experimental asthma caused by IgE antibody in rats was inhibited by HSR-6071 (6-(1-pyrrolidinyl)-N-(1H-tetrazol-5-yl)-2-pyrazinecarboxamide) (0.01-0.1 mg kg−1 i.v.) in a dose-dependent manner. The inhibitory activity of HSR-6071 was more potent than those of disodium cromoglycate and ketotifen, and equipotent with amlexanox. The bronchoconstriction mediated by IgE or IgG antibody in guinea-pigs was also prevented by HSR-6071 (0.3, 1 and 3 mg kg−1 i.v.), amlexanox (3, 10 and 30 mg kg−1 i.v.) and ketotifen (0.1 mg kg−1 i.v.) but not by disodium cromoglycate (10 mg kg−1 i.v.). HSR-6071 was more potent than amlexanox, but less potent than ketotifen. HSR-6071 suppressed antigen-induced histamine and SRS-A release from minced lung tissues of guinea-pigs sensitized passively with rabbit anti-EA serum and was a more potent inhibitor of the release of SRS-A than of histamine. On the other hand, histamine- or acetylcholine-induced bronchoconstriction in guinea-pigs was scarcely affected by HSR-6071 at doses sufficient to inhibit the experimental asthma, but LTD4-induced bronchoconstriction was dramatically inhibited. These results indicate that the inhibitory action on experimental allergic asthma of HSR-6071 may be due to suppression of antigen-induced histamine and SRS-A release from lung tissues and to antagonism of SRS-A action. In addition, HSR-6071 inhibited cyclic AMP phosphodiesterase activity and produced relaxation of the guinea-pig isolated trachea. These pharmacological actions may contribute to the production of the anti-allergic action of HSR-6071.
The effect of moisture content on the compression properties of maltodextrins
Authors: Li L C , Peck G E 
Published: April 2011

Abstract
The effect of moisture content on the compression properties of maltodextrin powders obtained by different degrees of hydrolysis (depolymerization) of corn starch has been studied using the yield pressure determined from the Heckel plot and the compact tensile strength measured by the diametrical compression method. An increase in the moisture content of the powder reduced the yield pressure and improved the densification for all five maltodextrins evaluated. At the same moisture level, the extent of densification which occurred during compaction was greater for maltodextrins with a lower degree of polymerization. Compacts produced by maltodextrins with a lower degree of polymerization also exhibited a greater tensile strength for a given pressure at a moisture content below 8 0%. However, further increase in moisture content resulted in a decrease in compact tensile strength for maltodextrins having a lower degree of polymerization. Despite the significant difference in compression behaviour, the five maltodextrins did not show noticeable differences in crystallinity as revealed by their x-ray powder diffraction pattern.
Lipid peroxidation effects of a novel iron compound, ferric maltol. A comparison with ferrous sulphate
Authors: Singh Rajiv K , Barrand Margery A 
Published: April 2011

Abstract
Lipid peroxidation effects of ferric maltol have been compared with those of ferrous sulphate both in lecithin liposomes and in brush border and mitochondrial membranes prepared from rat small intestine. Ferrous sulphate, but not ferric maltol, initiated peroxidation in liposomes as measured by conjugated diene production, but, with 500 μM ascorbic acid present, both caused intense peroxidation which was inhibitable by N2, tocopherol, maltol and ferrous chelators, but not by OH or H2O2 scavengers. The rate of peroxidation increased with ferrous sulphate concentration up to 100 μM but was independent of ferric maltol concentration between 5–500 μM. Material eluted from rat small intestine contained a reducing factor, similar in size to ascorbic acid, capable of generating ferrous ions from ferric maltol and initiating peroxidation. Peroxidation in mitochondrial membranes appeared unaffected by addition of iron whilst that in brush border membranes was detectable only in the presence of iron. At iron concentrations of 100 μM and above ferric maltol produced less liposomal peroxidation than ferrous sulphate. Maltol itself may delay recycling of Fe3+ to Fe2+. Thus ferric maltol could provide a less toxic alternative to ferrous salts in the oral treatment of iron-deficiency.