bluuebunny/crossref_metadata_2025_split huggingface dataset:
Hypophysectomy does not prevent increased cerebral dopamine turnover following sulpiride administration
Authors: Reynolds L M , Dyer R G , Jenner P , Marsden C D 
Published: April 2011

Abstract
Hypophysectomy is claimed to prevent increased forebrain dopamine turnover produced by administration of sulpiride. We have measured the increase in dopamine metabolite concentrations caused by sulpiride following surgical removal of the pituitary. In saline-treated control animals and in hypophysectomized rats 1 week or 1 month following surgery, administration of sulpiride caused marked elevations of striatal, nucleus accumbens and tuberculum olfactorium, homovanillic acid (HVA) and 3,4-dihydroxyphenylacetic acid (DOPAC) concentrations which were maximal 4–8 h following drug administration. The maximal increases in nucleus accumbens and tuberculum olfactorium were generally comparable in control and hypophysectomized animals, except for a greater increase in HVA levels in the nucleus accumbens 1 month following hypophysectomy. However, maximal increases in HVA and DOPAC in striatum were more pronounced in hypophysectomized rats 1 week or 1 month following surgery compared with control animals. At 30 min following sulpiride administration only inconsistent changes in dopamine turnover were observed in both control and hypophysectomized rats. Hypophysectomy does not prevent sulpiride from increasing forebrain dopamine turnover suggesting this is due to a direct interaction with cerebral dopamine receptors.
Adjustment of precompression force to reduce mixing-time dependence of tablet tensile strength
Authors: Vezin W R , Khan K A , Pang H M 
Published: April 2011

Abstract
The dependence of tablet tensile strength on lubricant mixing time, pre- and main compression pressure was measured with microcrystalline cellulose, dicalcium phosphate dihydrate and starch 1500 on a rotary tablet machine. Loss of tablet tensile strength arising from lubricant overmixing can be substantially reduced in the case of microcrystalline cellulose by adjustment of pre- and main compression. This facility may be used in addition to or instead of reducing mixing time, or displacing lubricant by adding extra formulation components.
Methadone radioimmunoassay: two simple methods
Authors: Robinson Katherine , Smith R N 
Published: April 2011

Abstract
Two simple and economical radioimmunoassays for methadone in blood or urine are described. Haemolysis, decomposition, common anticoagulants and sodium fluoride do not affect the results. One assay uses commercially-available [1−3H](-)-methadone hydrobromide as the label, while the other uses a radioiodinated conjugate of 4-dimethylamino-2,2-diphenylpentanoic acid and L-tyrosine methyl ester. A commercially-available antiserum is used in both assays. Normethadone and α-methadol cross-react to a small extent with the antiserum while methadone metabolites, dextropropoxyphene, dipipanone and phenadoxone have negligible cross-reactivities. The ‘cut-offs’ of the two assays as described are 30 and 33 ng ml−1 for blood, and 24 and 21 ng ml−1 for urine. The assay using the radioiodinated conjugate can be made more sensitive if required by increasing the specific activity of the label.
Acute effects on plasma lipids in the rat of a new long-acting nicotinic acid derivative: LG 13979
Authors: Subissi A , Criscuoli M , Biagi M , Murmann W 
Published: April 2011

Abstract
The effects on plasma lipids and nicotinic acid concentrations of a single dose of 2-(3-pyridinecarbonylamino)-2-deoxy-1,3,4,6 dihydrogen-D-glucose tetra-3-pyridinecarboxylate (LG 13979) compared with the effects of nicotinic acid and of its known derivatives niceritrol and sorbinicate, at the same doses, were studied in the fasted rat. Results show that LG 13979 has more prolonged activity on plasma free fatty acids and triglycerides, with longer lasting and more intense activity on plasma cholesterol than these three reference standards. Free fatty acid rebound occurs after administration of nicotinic acid and niceritrol, but not after LG 13979. This pharmacodynamic profile may be explained on the basis of the kinetics of nicotinic acid plasma concentrations, which are low, constant and lasting after LG 13979 administration.
Effects of aspirin, indomethacin, flufenamic acid and paracetamol on prostaglandin output from rat stomach and renal papilla in-vitro and ex-vivo
Authors: Danon Abraham , Leibson Valentina , Assouline Georges 
Published: April 2011

Abstract
The effects of aspirin, indomethacin, flufenamic acid and paracetamol on prostaglandin (PG) biosynthesis were studied in whole cell preparations of rat renal papilla and stomach in-vitro and ex-vivo. In the ex-vivo experiments a low dose aspirin was a potent inhibitor of PGE output from the stomach but not the renal papilla, while in-vitro renal PGE output was inhibited by aspirin to a greater extent than gastric PGE. Indomethacin and flufenamic acid inhibited both renal papillary and gastric PGE outputs in-vitro and ex-vivo. Paracetamol enhanced PGE output from the stomach more than twice ex-vivo, and to a lesser extent in-vitro. It also augmented PGE output from the papilla ex-vivo but not in-vitro. In view of the possible contribution of cellular organization and pharmacokinetic processes to the ultimate effect, it is suggested that studies on the effects of anti-inflammatory and antipyretic agents on PG biosynthesis should not be restricted to fully in-vitro systems.
α-Adrenoceptor subtypes and Ca2+ mobilization the rabbit ear artery
Authors: Manzini Stefano , Maggi Carlo Alberto , Meli Alberto 
Published: April 2011

Abstract
The mobilization of cellular and extracellular Ca2+ pools by selective α1-adrenoceptor (phenylephrine) and α2-adrenoceptor (xylazine) agonists as well as noradrenaline was evaluated in rabbit ear artery. Noradrenaline and phenylephrine possess full instrinsic activity for both types of Ca2+ mobilization whereas xylazine up to 1 mM had only a limited contractile effect, being more effective in inducing extracellular Ca2+-dependent response. However, extracellular Ca2+ was mobilized by xylazine in a concentration 20 times higher than that required to stimulate pre-junctional α2-adrenoceptors. Noradrenaline (5 μM) and xylazine (1 mM) induced cellular and extracellular Ca2+-dependent contractions which were prazosin-sensitive and yohimbine-resistant. Xylazine-induced contractile activity, particularly that dependent upon the extracellular Ca2+ pool, was markedly reduced by selective adrenergic denervation with 6-hydroxydopamine, but the actions of noradrenaline were unaffected. These results suggest that: (1) rabbit ear artery contain post-junctional α1-adrenoceptor but not α2-adrenoceptors; (2) stimulation of these α1-adrenoceptors can account for the overall contractile activity of exogenously added noradrenaline and (3) stimulation of α1-adrenoceptors results in mobilization of cellular as well as extracellular Ca2+ pools.
Phase studies of ethoxylated surfactants-oil-water-undecylenic acid
Authors: Bulut F , Yalabik-Kas H S , Hincal A A 
Published: April 2011

Abstract
Two non-ionic surfactants (Simulsol OL 50 and Simulsol 98) separately or as 1:1 mixtures, together with corn oil-undecylenic acid and water formed various phases. Phase equilibrium studies were made. In all phase equilibrium diagrams investigated, both at 20 and 37°C, lamellar and hexagonal liquid crystalline and oily isotropic phases were found, besides the emulsion system. Emulsions were composed of mixed lamellar and hexagonal liquid crystalline phases which formed at low concentrations of surfactant and oil and correspondingly high water concentrations.
Photolytic degradation of frusemide
Authors: Moore Douglas E , Sithipitaks Varavudh 
Published: April 2011

Abstract
Irradiation with 365 nm u.v. light of frusemide (4-chloro-N-furfuryl-5-sulphamoyl-anthranilic acid) in methanol results primarily in photoreduction to N-furfuryl-5-sulphamoylanthranilic acid and photohydrolysis to 4-chloro-5-sulphamoylanthranilic acid (saluamine).
The production and properties of gel precipitated aluminium hydroxide spheres containing imipramine
Authors: Ramsey M P , Shaw G G , Newton J M , Lane E S , Sammon D C 
Published: April 2011

Abstract
The production of aluminium hydroxide spheres containing imipramine by gel precipitation of liquid feed solutions has been described. Washing and heating procedures applied to the precipitated spheres markedly affected the rate of drug release from the spheres into 0·1m hydrochloric acid. Increasing the imipramine content of the spheres also altered the drug release rate. The effects described have been explained with reference to model theories of the precipitation and ageing of aluminium hydroxide gels in the presence and absence of ‘foreign’ anions.
The assay of tropane derivatives in formulations by second derivative ultraviolet spectrophotometry
Authors: Hassan S M , Davidson A G 
Published: April 2011

Abstract
The development of a second order derivative spectrophotometric assay of atropine, hyoscine and benztropine in formulations is described. The assay involves the extraction into 1,2-dichloroethane of the tetraphenylborate salt of the alkaloids precipitated from pH 6 solution by an excess of sodium tetraphenylboron and measurement of the amplitude near 273 nm to its shorter wavelength satellite in the second derivative spectrum. The second derivative amplitude gives a more precise determination of the alkaloids than absorbance. A two-point bracketting standardization of the amplitude is required owing to a small but significant intercept in the calibration data. The procedures are sufficiently sensitive and precise for the batch and unit-dose assay of tablets of atropine sulphate (0·6 mg) hyoscine hydrobromide (0·3 mg) and benztropine mesylate (2 mg), and for the assay of atropine sulphate injection (0·4 mg ml−1) and tincture of belladonna.
Differential effects of vasodilators on the mobilization of calcium pools during contractions of rabbit ear artery induced by noradrenaline and high potassium
Authors: Maggi Carlo Alberto , Manzini Stefano , Meli Alberto 
Published: April 2011

Abstract
The effects of some vasodilators on the mobilization of different Ca2+ pools during contractions produced by noradrenaline and high K+ medium in rabbit ear artery has been investigated. Sodium nitrite was much more effective in antagonizing high K+-stimulated Ca2+ fluxes through the potential-dependent Ca2+ channels than noradrenaline-induced mobilization of intracellular Ca2+ stores or Ca2+ fluxes through receptor-operated channels. Papaverine was only slightly more active on contractions sustained by influx of extracellular Ca2+ (through potential-dependent channels and receptor-operated channels) than on those sustained by intracellular Ca2+. Verapamil and nifedipine were much more effective in antagonizing contractions sustained by Ca2+ entry through potential-dependent channels than through receptor-operated channels. Nifedipine was completely ineffective in antagonizing noradrenaline-induced mobilization of intracellular Ca2+ stores while verapamil had a limited inhibitory action in high concentrations. Phentolamine was equieffective in antagonizing both types of noradrenaline-induced contractions while having no effect on high K+-induced tonic contraction.
Effect of food, fluid and dosage form on the absorption of 52–522, a potential antianxiety agent, in the dog
Authors: Tse Francis L S , Jaffe James M , Marty Karen A , Schwarz Hans J 
Published: April 2011

Abstract
The absorption of 52–522 in the dog was studied by measuring blood concentrations of radioactivity after single oral doses of [14C] 52–522 in a capsule with and without water, also as a food-drug mixture, and a solution in polyethylene glycol 400. Absorption was rapid, and its rate moderate with no significant differences in peak times among treatments. The extent of absorption was lowest after the capsulated [14C] 52–522. The solution dose gave elevated blood concentrations, that were statistically significantly different when compared with the capsules. Hence, it appears that the absorption of [14C] 52–522 is governed by the degree of dispersion of drug in the dosage form.
Increased brain uptake of morphine in the presence of the antihistamine tripelennamine
Authors: Vadlamani N L , Pontani R B , Misra A L 
Published: April 2011

Abstract
Disposition of [6 3H (N)]morphine in plasma, brain and liver of rats was studied 15 min after intravenous injection of either a 2 mg kg−1 dose of morphine or a combination of the same dose of morphine with a 6 mg kg−1 dose of tripelennamine. The concentrations of morphine in brain and the brain to plasma morphine ratios in animals receiving the combination of drugs concurrently were significantly higher than those in the control morphine group. No significant differences were seen in the morphine or morphine metabolite concentrations in plasma and liver or liver to plasma morphine concentration ratios in the 2 groups. Data suggest that pharmacokinetic factors play a role in the potentiation of opiate effects by antihistamine on concurrent i.v. administration of the two drugs.
Influence of ricinoleic acid on the contractions elicited by PGE2 on the guinea-pig ileum
Authors: Capasso F , Mascolo N , Autore G , Duraccio M R 
Published: April 2011

Abstract
The effect of ricinoleic acid on prostaglandin E2 (PGE2)-evoked contractions was studied on guinea-pig isolated ileum. Addition of ricinoleic acid (10 μg ml−1) to the organ bath increased the amplitude of the PGE2-evoked responses. Ricinoleic acid (10 μg ml−1) also sensitized the guinea-pig isolated ileum to acetylcholine and histamine. The effect of the ricinoleic acid was greatly reduced by indomethacin either in-vivo (10 mg ml−1) or in-vitro (2 μg ml−1).
Evidence that drugs increasing 5-hydroxytryptamine transmission block jumping but not wet dog shakes in morphine-abstinent rats: a comparison with clonidine
Authors: Romandini S , Cervo L , Samanin R 
Published: April 2011

Abstract
(+)-Fenfluramine, a 5-hydroxytryptamine (5-HT) releaser and uptake blocker, m-chlorophenylpiperazine (CPP), a 5-HT receptor agonist, and clonidine, an agonist at adrenoceptors, were studied for their ability to modify jumping and wet dog shakes in morphine abstinent rats. (+)-Fenfluramine and CPP blocked jumping with no effect on wet dog shakes whereas the reverse was true for clonidine. The results further show that 5-HT mechanisms are preferentially involved in the expression of jumping in morphine-abstinent rats.
Comparative effects of inhibitors of the lipoxygenase enzyme system on leucocyte chemotaxis
Authors: Kitchen E A , Dawson W 
Published: April 2011

Abstract
The chemotactic response, towards zymosan activated serum (ZAS), of elicited peritoneal exudate leucocytes was assessed in-vitro after treatment with inhibitors of the lipoxygenase enzyme pathway. Leucocytes from both rat and guinea-pig were used. BW755C and benoxaprofen reduced the chemotaxis of mononuclear cells from both species at 10−4 m. Nordihydroguaiaretic acid (NDGA) at 7·5 times 10−6 m depressed the chemotaxis of rat mononuclear cells but failed to modify the response of guinea-pig mononuclear cells. NDGA, BW755C and benoxaprofen, at concentrations that inhibit the lipoxygenase enzyme pathway in-vitro, were ineffective in reducing the chemotactic response of rat PMN. All three agents potentiated guinea-pig PMN chemotaxis, to a greater or lesser extent, the most pronounced effect being with NDGA when increased PMN migration was accompanied by an increased detachment of cells from the lower surface of the filters. The effects of these agents on both cellular chemotaxis and adherence are not necessarily related to their inhibitory effects on the lipoxygenase enzyme pathway.
The rapid estimation of strychnine in tincture of nux vomica BP by high-performance liquid chromatography
Authors: Dennis R 
Published: April 2011

Abstract
Strychnine is separated from other alkaloids in nux vomica tincture in less than 6 min on a 12·5 cm Hypersil column using a mobile phase of methanol, 2 m ammonium hydroxide, m ammonium nitrate (27:2:1), uv detection at 254 nm. Quantitative estimation may be obtained by comparing peak area or height against an external standard (0·150% w/v strychnine base in 45% ethanol). The results obtained were comparable to those obtained by the BP method which takes 5 h.
Absorption of acetylsalicylic acid from enteric-coated tablets in relation to gastric emptying and in-vivo disintegration
Authors: Bogentoft Conny , Alpsten Magne , Ekenved Gunnar 
Published: April 2011

Abstract
The absorption of acetylsalicylic (ASA) acid from enteric coated tablets was studied in relation to gastric emptying and in-vivo disintegration. ASA tablets labelled with 51Cr were given to six healthy subjects under fasting and non-fasting conditions. The position and disintegration of the 51Cr-labelled tablets was followed by external radiation measurement and the amount of salicylic acid in blood and urine was analysed. The absorption of ASA from the studied enteric coated tablets was usually correlated with gastric emptying and in-vivo disintegration. However in some cases the absorption can be delayed between 10–20 h even if gastric emptying and disintegration of the tablet have occurred.
Endocrine dependence of prostatic cancer upon dihydrotestosterone and not upon testosterone
Authors: Petrow V , Padilla G M , Mukherji S , Marts S A 
Published: April 2011

Abstract
Growth of the Dunning R3327−H prostatic adenocarcinoma, implanted in the rat, is inhibited by 6−methylene progesterone. This compound is a potent inhibitor of rat prostatic 5-α-reductase and in-vivo produces marked involution of the prostate. Thus the tumor requires dihydrotestosterone and not testosterone for growth.
SCH 23390 can enhance field stimulation-induced contractions of longitudinal smooth muscle from guinea-pig stomach
Authors: Costall Brenda , Gunning Simon J , Naylor Robert J 
Published: April 2011

Abstract
Field stimulation-induced contractions of guinea-pig stomach longitudinal muscle strips were enhanced by metoclopramide (a D−2 receptor antagonist) and SCH 23390 (a D−1 receptor antagonist) but not by cis-flupenthixol (a D−1 and D−2 receptor antagonist) or sulpiride (a D−2 receptor antagonist). SCH 23390 is the first non-benzamide neuroleptic drug shown to enhance cholinergic mediated contraction responses of gastric smooth muscle, but the response does not appear to reflect a D−1 receptor antagonism.
Drug migration into soft gelatin capsule shells and its effect on in-vitro availability
Authors: Armstrong N A , James K C , Pugh W K L 
Published: April 2011

Abstract
Analysis of the shells and contents of soft gelatin capsules containing acetomenaphthone, ephedrine, 4−hydroxybenzoic acid or phenobarbitone, dissolved in isopropyl myristate, revealed that the percentage of solute taken up by the shells increased with increasing aqueous solubility of the substrate. Thus no acetomenaphthone, which has a negligible aqueous solubility, was found in the shells, in comparison with 92% of the 4-hydroxybenzoic acid, which has a significant solubility in water. Uptake was not influenced by the solubility in isopropyl myristate. The effect of the oily solvent was studied using blends of 1-octanol and isopropyl myristate in which either 4−hydroxybenzoic acid or phenobarbitone were dissolved. Solute release shows that both release and migration can be predicted from a knowledge of the aqueous solubility of the solute and its partition coefficient between water and the non-polar solvent. Samples of capsules containing 4-hydroxybenzoic acid in isopropyl myristate were withdrawn at various stages of the manufacturing process, and the distributions between shell and contents noted. Most of the transfer took place while the capsules were being dried in rotating basket driers, and at this point 67% of the acid had migrated. This increased to 92% during tray drying, and remained so for at least 6 months after manufacture.
GABAB receptor mediated inhibition of field stimulation-induced contractions of rabbit bladder muscle in-vitro
Authors: Santicioli Paolo , Maggi Carlo Alberto , Meli Alberto 
Published: April 2011

Abstract
The effects of GABA and selective GABAA and GABAB receptor agonists and antagonists have been investigated on field stimulation-induced contractions (0·1 Hz) of rabbit urinary bladder strips in-vitro. Atropine inhibits twitches of bladder strips obtained from the bladder dome more effectively than those obtained from the bladder base. Both GABA and the selective GABAB receptor agonist, (±)-baclofen inhibited field stimulation-induced contractions to about the same extent, while the selective GABAA receptor agonist, homotaurine had no effect. In the presence of atropine, GABA failed to inhibit further the amplitude of twitches. The effects of either GABA or (±)-baclofen were antagonized by the GABAB receptor antagonists homotaurine and 5−aminovaleric acid, while the GABAA receptor antagonist picrotoxin had no effect. Neither GABA nor (±)-baclofen had any significant effect on acetylcholine-induced contractions of unstimulated bladder strips, but they were abolished by atropine. These results suggest that GABAB receptors inhibit field stimulation-induced contractions of rabbit bladder muscle by reducing the amount of acetylcholine released per nerve impulse.
No correlation exists between antidepressant activity and the ability of 5−HT uptake inhibitors to interact with 5−HT receptors of the rat stomach fundus strip
Authors: Pawlowski Leszek , Kwiatek Halina 
Published: April 2011

Abstract
Several 5−HT uptake inhibitors, established and potential antidepressant drugs, were tested for their ability to counteract contractions of the rat isolated stomach fundus strip induced by 5−HT and BaCl2. Of 12 inhibitors tested, only doxepine, amitriptyline, clomipramine, imipramine, Ro 11–2465 (cyan-imipramine), citalopram and fluvoxamine antagonized the contraction induced by 10−6 m 5−HT with IC50 values below 10−4 m. Amitriptyline, doxepine and cyproheptadine, at concentrations inhibiting the effect of 5−HT, did not antagonize the strip contractions induced by 3 times 10−3 m BaCl2, while the remaining compounds that antagonized 5−HT-induced contractions, also antagonized–-with at least a similar potency–-the contractions induced by BaCl2. From among antidepressant compounds investigated, only doxepine and amitriptyline may be regarded as antagonists of the 5−HT receptor in the rat stomach strip.
Quantitation of norantipyrine sulphate and norantipyrine glucuronide as major metabolites of antipyrine in man and rat
Authors: Böttcher J , Bässmann H , Schüppel R 
Published: April 2011

Abstract
Two assay procedures are described for the quantitation of norantipyrine sulphate and norantipyrine glucuronide present in biological material. One, a selective acid hydrolytic assay procedure that affords the discriminative determination of both conjugates without prior separation, measures free norantipyrine by tlc-uv. The other is a tlc separation procedure for intact norantipyrine conjugates, which, in conjunction with radiolabelled material, derived from [3−14C]antipyrine, enables the direct quantitation of both conjugates independently. In man, about 25% of dose of antipyrine (1200 mg) was excreted as norantipyrine glucuronide within 48 h. The amount of norantipyrine sulphate was small. In the rat, norantipyrine sulphate represented about 15–20% of the dose of antipyrine (40–50 mg kg−1); no norantipyrine glucuronide was formed. Free norantipyrine has not been detected in urine of either species after antipyrine dosage. Pretreatment with 3-methylcholanthrene in the rat substantially enhanced excretion of norantipyrine sulphate, whereas induction with phenobarbitone was without effect on the microsomal N-demethylation of antipyrine. The lability of free norantipyrine was examined under different conditions and contrasted with the relative stability of norantipyrine conjugates. Two of the main degradation products of norantipyrine were identified as 4-phenylazo-norantipyrine and a 4,4−bipyrazole-derivative.