bluuebunny/crossref_metadata_2025_split huggingface dataset:
Regional and subcellular changes in the concentration of 5‐hydroxytryptamine and 5‐hydroxyindoleacetic acid in the rat brain caused by hydrocortisone, DL‐α‐methyltryptophan l‐kynurenine and immobilization
Authors: CURZON G. , GREEN A. R. 
Published: July 2012

Summary
In agreement with previous findings on whole brain, the intraperitoneal injection of hydrocortisone, DL‐α‐methyltryptophan or l‐kynurenine decreased the concentrations of 5‐hydroxytryptamine (5‐HT) and 5‐hydroxyindoleacetic acid (5‐HIAA) in different regions of the rat brain.
Hydrocortisone caused similar decreases in the concentrations of both 5‐HT and 5‐HIAA, suggesting decreased 5‐HT synthesis.
Changes in the concentration of 5‐HIAA after hydrocortisone corresponded significantly to those after α‐methyltryptophan. Changes in the concentration of 5‐HT did not correspond, possibly due to falsely high 5‐HT values because of interfering material derived from α‐methyltryptophan.
In general, kynurenine caused larger decreases in the concentration of 5‐HT than in the concentration of 5‐HIAA.
In agreement with previous findings with whole brain, immobilization of rats for 5 h decreased the concentration of 5‐HT and increased that of 5‐HIAA in most brain regions.
The order of the percentage decreases in the concentrations of 5‐HIAA 6 h after hydrocortisone injection was, in decreasing order: hypothalamus, striatum, cerebellum, mid‐brain, pons + medulla and cortex. The percentage increases after immobilization for 5 h were in the reverse order.
The differences between the percentage decreases in the concentration of 5‐HIAA after hydrocortisone and the percentage increases after immobilization were very similar in all regions except the hypothalamus. This is consistent with immobilization stress increasing the firing rate of 5‐hydroxytryptaminergic neurones similarly in different regions.
During the first 3 h of immobilization the concentrations of 5‐HIAA in the hypothalamus and in the rest of the brain increased approximately in parallel. Between 3 and 5 h, 5‐HIAA returned to control concentrations in the hypothalamus while continuing to rise in the rest of the brain.
Relative changes in the concentration of 5‐HT in particulate and supernatant fractions after the various treatments were comparable except 2 h after kynurenine injection when the concentration of 5‐HT fell in the particulate but not in the supernatant fraction. The concentration of 5‐HT did fall in the latter, though more slowly than in the former fraction, suggesting a concentration of amine synthesizing organelles in particulate material.
Selective blockade of the vasodepressor response to prostaglandin F2α in the anaesthetized rabbit
Authors: LEVY B. , LINDNER H. R. 
Published: July 2012

Summary
The prostaglandin‐blocking activity of meclofenamic acid, N‐(2,6‐dichloro‐m‐tolyl)anthranilic acid (CI‐583), was analysed in the anaesthetized rabbit. PGF2α, PGE1 and isoprenaline were injected before and after meclofenamic acid infusion.
Isoprenaline produced a fall in blood pressure, a reduction in oviduct motility and a reduction in uterine motility if the uterus showed marked spontaneous motility. PGF2α uniformly produced a fall in blood pressure and an increase in both uterine and oviduct contractility. PGE1 produced a fall in blood pressure, a reduction in oviduct motility and no consistent effect on uterine motility.
Meclofenamic acid selectively blocked the vasodepressor response to PGF2α. The vasodepressor responses to PGE1 and isoprenaline as well as the effects of all three agonists on uterine and oviduct contractility were not reduced by treatment with meclofenamic acid.
Polyphloretin phosphate (PPP) administered to two rabbits in a cumulative dose of 94 mg/kg showed no significant blocking action on the vasodepressor or uterine and oviduct contractor responses to PGE1 or PGF2α though this compound, like meclofenamic acid, has been reported to antagonize the actions of PGE1 and PGF2α on isolated smooth muscle preparations.
Effect of dopamine on pancreatic secretion in the dog
Authors: HASHIMOTO K. , SATOH S. , TAKEUCHI O. 
Published: July 2012

Summary
Effects of l‐dopa and dopamine on the secretion of pancreatic juice were investigated in preparations of the isolated blood‐perfused canine pancreas.
Dopamine (1–10 μg) given intra‐arterially caused a profuse flow of juice.
The secretory activity of dopamine (3 μg) was approximately equal to that of secretin (0·1 unit).
l‐Dopa (10–100 μg) given by a single intra‐arterial injection was ineffective, but infusion at 100 μg/min for 10 min caused a marked increase of secretion after a delay of a few minutes.
Intravenous administration of either l‐dopa (3 mg/kg) or dopamine (10–100 μg/kg) elicited a marked increase of pancreatic secretion, but was definitely less effective than intra‐arterial injection.
Dopamine‐induced secretion was not modified by atropine, phentolamine, propranolol, guanethidine or tetrodotoxin.
It is concluded that dopamine acts directly on the exocrine cells in the pancreas.
Kallikrein, trypsin‐like proteases and amylase in mammalian submaxillary glands
Authors: BHOOLA K. D. , DOREY GUNDULA 
Published: July 2012

Summary
The tissue concentration of kallikrein, trypsin‐like proteases and amylase has been determined in the submaxillary glands of the cat, dog, rabbit, rat, hamster and guinea‐pig.
Submaxillary gland extracts of the six species showed a wide variation in kallikrein content. The esterase activity in the extracts, however, did not correlate with the kininogenase activity of kallikrein. Both activities in each of the six species were affected by proteinase inhibitors but not in the same way.
Evidence is presented which indicates that trypsin‐like proteases similar to those described in the rat, also occur in the hamster and cat submaxillary glands.
An even greater spread of amylase activity was observed between the species.
The assumption that mammalian submaxillary kallikreins are identical proteins is questioned.
Effect of inhibition of catecholamine synthesis on central catecholamine‐containing neurones in the developing albino rat
Authors: LOIZOU L. A. 
Published: July 2012

Summary
Tyrosine hydroxylase is thought to be the rate limiting enzyme step in catecholamine biosynthesis. Inhibition of this enzyme using α‐methyl‐p‐tyrosine resulted in a time dependent depletion (and repletion) of formaldehyde induced fluorescence in catecholamine‐containing neurones of the central nervous system in developing and adult rats.
Dopamine‐containing neurones were depleted faster and more completely than noradrenaline‐containing neurones.
The extent of depletion caused by α‐methyl‐p‐tyrosine in the initial 6–9 h period was more or less comparable in young and adult rats from the age of 1 week onwards; this suggests that catecholamine turnover increases with age and parallels the increase in catecholamine levels.
The extent of depletion (and repletion) 18 h after administration of the inhibitor varied in animals of different age.
Administration of a monoamine oxidase inhibitor just before administration of α‐methyl‐p‐tyrosine resulted in a reduction of the extent of depletion caused by the latter drug, indicating that monoamine oxidase is important for the breakdown of catecholamines in rats of all ages.
It is suggested that the catecholamine‐containing neurones of the newborn are biochemically as well as functionally differentiated before completion of morphological differentiation.
Control of pancreatic amylase release in vitro: effects of ions, cyclic AMP, and colchicine
Authors: BENZ L. , ECKSTEIN B. , MATTHEWS E. K. , WILLIAMS J. A. 
Published: July 2012

Summary
. The time course and concentration‐response relationship of amylase release from pieces of guinea‐pig pancreas in vitro in response to bethanechol and pancreozymin was determined.
. Removal of Ca++ from the medium had no effect on basal amylase release but abolished the stimulating effect on release of bethanechol.
. Elevation of the concentration of Mg++ in the medium increased basal amylase release and reduced the response to bethanechol.
. Elevation of the concentration of K+ in the medium increased amylase release; this effect was blocked by a concentration of atropine which blocked also the response to bethanechol.
. Cyclic AMP, dibutyryl cyclic AMP and theophylline failed to stimulate amylase release. Pancreatic cyclic AMP concentrations were found not to be increased by bethanechol, pancreozymin or an elevated concentration of K+ in the medium.
. Colchicine had no effect on basal amylase release or the response to bethanechol or pancreozymin.
. It is concluded that the coupling of stimulus to secretion involves ionic control but that neither cyclic AMP production nor microtubular mechanisms play a major role in controlling exocytosis in the pancreatic acinar cell. These findings are discussed in relation to the stimulus‐secretion coupling processes in other cells.
Anaesthetic, cardiovascular and respiratory effects of a new steroidal agent CT 1341: a comparison with other intravenous anaesthetic drugs in the unrestrained cat
Authors: CHILD K. J. , DAVIS B. , DODDS M. G. , TWISSELL D. J. 
Published: July 2012

Summary
. The anaesthetic, cardiovascular, respiratory and adverse effects produced by the intravenous injection of CT 1341, thiopentone, methohexitone, pentobarbitone, propanidid and ketamine have been compared in unrestrained cats prepared with chronically implanted venous and arterial cannulae. Aortic blood pressure and heart rates were monitored before, during and after loss of consciousness.
. CT 1341 produced rapid induction of anaesthesia followed by moderately rapid recovery, was active over a wide range of doses and caused minimal respiratory depression and few adverse effects. It caused an initial short‐lasting tachycardia and fall in aortic blood pressure succeeded by a secondary depressor response.
. The safety margin was narrower with the barbiturate drugs than with CT 1341, and large doses induced apnoea and respiratory depression. Small doses of methohexitone elicited excitatory effects and large doses caused severe respiratory and circulatory depression, and recovery from anaesthesia was protracted.
. Propanidid induced short‐lasting light anaesthesia. The safety margin was narrowest with this drug and induction was associated with adverse circulatory, respiratory and other effects.
. Ketamine was active over a wide range of doses but exhibited qualitatively different properties from the other anaesthetics. Induction was slower after small doses and these produced circulatory stimulation, catatonia and bizarre behavioural effects. Large doses caused respiratory and circulatory depression and recovery was protracted.
. It is concluded that CT 1341 has a wider therapeutic latitude, produces less respiratory depression and has other advantages over the currently used intravenous anaesthetics.
A comparison of the excitatory and inhibitory effects of non‐adrenergic, non‐cholinergic nerve stimulation and exogenously applied ATP on a variety of smooth muscle preparations from different vertebrate species
Authors: BURNSTOCK G. , SATCHELL D. G. , SMYTHE ANNE 
Published: July 2012

Summary
. The responses to non‐adrenergic, non‐cholinergic nerve stimulation have been compared with those to exogenously applied ATP on seventeen different tissues from a number of vertebrate classes.
. Stimulation of all the mammalian gut preparations studied (with the exception of the guinea‐pig ileum) after blockade of the effects of adrenergic and cholinergic nerve stimulation by guanethidine (3·5 μm) and hyoscine (1–3 μm) caused inhibition; exogenously applied ATP mimicked this inhibitory response.
. Stimulation of the guinea‐pig ileum in the presence of hyoscine and guanethidine, usually caused a diphasic response, relaxation followed by contraction; exogenously applied ATP mimicked this response, in contrast to acetylcholine and noradrenaline which caused excitation and relaxation respectively.
. Stimulation of preparations of lower vertebrate gut and guinea‐pig bladder in the presence of hyoscine and guanethidine caused contraction; exogenously applied ATP mimicked this contractile response.
. In each preparation the time course of the response to ATP was similar or identical to the response to non‐adrenergic, non‐cholinergic nerve stimulation.
. The results are consistent with the hypothesis that a purine nucleotide may be the transmitter substance released from non‐adrenergic, non‐cholinergic nerves supplying smooth muscle preparations from a number of vertebrate classes.
Effect of external lymph drainage and of coumarin treatment on thermal injury in the rat hind leg
Authors: FÖLDI‐BÖRCSÖK ETHEL 
Published: July 2012

Summary
. External lymph drainage brings about a significant protective effect in thermal oedema of the rat hind leg. It is suggested that external lymph drainage prevents vasoactive substances drained from the site of injury from passing into the blood stream, which would further increase permeability of the injured blood capillaries.
. Coumarin (5,6‐benzo‐alpha‐pyron) brings about a significant protective effect against the same injury in sham‐operated rats.
. The strongest protective effect may be attained by combining external lymph drainage with the administration of coumarin.
. The additional therapeutic effect brought about by coumarin treatment in rats with external lymph drainage is not mediated by an increased flow. The possible mechanisms are discussed.
Pharmacokinetic and toxicological studies of antimony dextran glycoside (RL‐712)
Authors: CASALS J. BOU 
Published: July 2012

Summary
. The absorption, tissue distribution and excretion of antimony dextran glycoside (RL‐712) has been studied in normal rodents.
. Some organs in the body, especially liver and spleen, retain large amounts of antimony for considerable periods of time. Excretion of antimony in the urine was low and only about 10–12% of the dose administered was excreted within the first 48 hours.
. Blood levels were maintained for at least 3 days after a single intramuscular dose to rabbits, corresponding to 14 mg Sb/kg body weight.
. Toxicity studies and tests on foetal toxicity in mice and rats, respectively, showed no abnormalities.
. The possible value of RL‐712 in the prophylaxis and treatment of leishmaniasis is discussed.
Acceleration of catecholamine biosynthesis in sympathetically innervated tissues by angiotensin‐II‐amide
Authors: BOADLE‐BIBER MARGARET C. , HUGHES J. , ROTH R. H. 
Published: July 2012

Summary
. The effect of angiotensin‐II‐amide on the biosynthesis of catecholamines (CA) has been studied in a number of isolated tissues in vitro.
. Angiotensin increased the synthesis of CA from 14C‐tyrosine in guinea‐pig atria and portal vein, in rat vasa deferentia and the rabbit portal vein.
. Angiotensin had no effect on synthesis of CA from 14C‐labelled dl‐DOPA.
. The conditions required to demonstrate an increased synthesis were critical with respect to incubation time and angiotensin concentration. Effects were most readily apparent after incubation for 1 h with concentrations of angiotensin ranging from 10−9 to 10−7m. Higher concentrations caused a significant reduction in synthesis.
. An increased release of newly synthesized CA into the incubation medium was sometimes seen in the presence of angiotensin. However, there was no correlation between increased synthesis and release of CA.
. Angiotensin was rapidly destroyed when incubated with guinea‐pig or rat tissues in Krebs solution. The increase in CA synthesis was only apparent at a time when the incubation medium could have contained only a fraction of the original angiotensin activity.
. It is concluded that the effect of angiotensin is not due to increased release of noradrenaline (NA) or to inhibition of NA uptake into nerves. It is possible that angiotensin may influence the activity of tyrosine hydroxylase or its cofactors by an as yet unknown mechanism.
Inhibition of catecholamine uptake in the isolated rat heart by haloalkylamines related to phenoxybenzamine
Authors: IVERSEN L. L. , SALT P. J. , WILSON H. A. 
Published: July 2012

Summary
. Twenty‐one haloalkylamine derivatives were tested as inhibitors of both the neuronal uptake of 3H‐noradrenaline (NA) by the Uptake1 mechanism and the extraneuronal uptake of 3H‐NA by the Uptake2 mechanism in the isolated rat heart.
. At a concentration of 50 μm most of the compounds tested caused a significant inhibition of both uptake processes, although there were wide differences in the relative effects on Uptake1 and Uptake2. Some tentative structure activity relationships for uptake inhibition were formulated from these results.
. Phenoxybenzamine was confirmed to be a potent inhibitor of both the Uptake2 and Uptake1 mechanisms, with IC50 values for these two systems of 2·8 μm and 0·9 μm respectively.
. The substances N‐(9‐fluorenyl)‐N‐methyl‐β‐chloroethylamine (SKF 550), N‐(3,4‐dimethoxyphenylisopropyl)‐N‐benzyl‐β‐chloroethylamine (SKF 625A) and N‐(4‐methoxyphenoxyisopropyl)‐N‐benzyl‐β‐chloroethylamine (SKF 784A) were significantly more potent than phenoxybenzamine as Uptake2 inhibitors, and were all less potent than phenoxybenzamine as Uptake1 inhibitors. The compound SKF 550 is the most potent and selective inhibitor of Uptake2 so far described. It has an IC50 for Uptake2 of 008 μm, and an IC50 for Uptake1 of approximately 400 μm.
. Comparison of the present results with the known activities of these blocking agents suggests that no correlation exists between adrenoceptor blocking activity and ability of the substances to act as inhibitors of Uptake2 or Uptake1.
The actions of dehydroemetine on isolated guinea‐pig atria. Influence of ouabain and calcium
Authors: SALAKO L. A. 
Published: July 2012

Summary
. The mechanism of the inhibitory effect of dehydroemetine on the heart was investigated using (a) the spontaneously contracting isolated guinea‐pig atrial preparation and (b), the electrically driven left atrial preparation.
. Dehydroemetine decreased the rate and amplitude of contraction of spontaneously contracting atria.
. Increasing the calcium concentration of the bath fluid to 28·2 mm abolished the effect of dehydroemetine on amplitude of contraction while the effect on rate persisted.
. Pretreatment with dehydroemetine increased the capacity of ouabain to induce arrhythmias in spontaneously contracting atria. Similarly pretreatment with ouabain augmented the inhibitory effect of dehydroemetine on spontaneous atrial activity.
. In the electrically driven left atrial preparation, dehydroemetine caused a decrease in contractile strength which was opposed by ouabain and by increased calcium concentration of the bath fluid.
. The effect of dehydroemetine on spontaneously contracting and on electrically driven atria was mimicked by adding excess potassium to the bath fluid.
. It was concluded that the effects of dehydroemetine on rate and contractility are, to a large extent, independent of one another. The effect on spontaneous rate is consistent with alteration of the potassium permeability of the myocardial cell membrane while the effect on contractility appears to be due to a decrease in the uptake of calcium from the medium by the myocardial cell.
Respiratory responses to chemical pulses in the cerebrospinal fluid of cats
Authors: BORISON H. L. , HARANATH P. S. R. K. , McCARTHY L. E. 
Published: July 2012

Summary
In cats anaesthetized with pentobarbitone, the fluid spaces in and around the brain stem were perfused from the third ventricle to the foramen magnum with artificial cerebrospinal fluid (c.s.f.) flowing usually at the rate of 5 ml/minute. Test solutions were substituted for the artificial c.s.f. without switching artifact for periods varying from 5 to 60 seconds. Observations were made on respiratory excursions, end‐expiratory % CO2 and arterial blood pressure.
Perfusion with sucrose solution equiosmolar with the c.s.f. produced no respiratory or cardiovascular response. Replacement of sodium with potassium (60 to 133 mm) resulted in a prompt but mild respiratory stimulation and a delayed fall in blood pressure associated with a slowing of the heart beat. Replacement of sodium with magnesium (40 to 131 mm) resulted in a late prolonged apneustic depression of breathing and in an early but slight reduction in blood pressure.
Procaine (1 to 50 mg/ml) elicited a respiratory response similar to that of excess magnesium; however, an initial rise in blood pressure to as high as 200 mmHg was evoked with procaine. Nicotine (0·05 to 0·5 mg/ml) produced an immediate brief bradypnea followed by a vigorous and slowly reversing hyperpnea accompanied most often by a fall in blood pressure. Tachyphylaxis was observed in the response to nicotine. Noradrenaline (0·001 and 0·1 mg/ml) did not produce any effect, and it did not alter the responses elicited by procaine and nicotine given by perfusion either simultaneous with or subsequent to the noradrenaline. Acetylcholine (0·5 mg/ml) produced weak transient respiratory stimulation and a small fluctuation in blood pressure which disappeared in repeated tests. Methacholine (1 mg/ml) caused a brief hyperpnea and a fall in blood pressure both of which were abolished after atropine (0·2 mg) was injected into the third ventricle. Pilocarpine (10 mg/ml) elicited no change in respiration or blood pressure. Respiratory and cardiovascular effects produced by strychnine (1 mg/ml) were attributable nonspecifically to convulsive movements of the animal. Ethamivan (1 mg/ml) produced a single deep breath and a slowly reversing rise in blood pressure. Cyanide (0·5 mg/ml) barely stimulated the respiration but it produced a long lasting rise in blood pressure. Ethyl alcohol (0·1 ml/ml) elicited brisk though brief respiratory stimulation and a short lasting fall in blood pressure.
It was shown that the effects of procaine and nicotine were not qualitatively altered when the perfusion effluent was collected through a ventral craniotomy instead of the cisterna magna.
It is concluded that the brain surfaces are insensitive to the substances tested and that the observed effects resulted from movement of the agents into the brain parenchyma.
Comparative study of six β‐adrenoceptive antagonists on airway resistance and heart rate in the guinea‐pig
Authors: ADVENIER C. , BOISSIER J. R. , GIUDICELLI J. F. 
Published: July 2012

Summary
The effects of six β‐adrenoceptive antagonists [(±)‐propranolol, (+)‐propranolol, (±)‐sotalol, (±)‐practolol, (±)‐pindolol and (±)‐procinolol] were studied on airway resistance and heart rate in guinea‐pigs and dose‐response curves constructed.
All β‐adrenoceptive antagonists decreased heart rate and increased airway resistance. A significant correlation was found between the increase in airway resistance and the degree of bradycardia induced by all drugs except practolol. The orders of activity of the six drugs in inducing significant variations of the two parameters were respectively, for airway resistance: (±)‐procinolol>(±)‐pindolol>(±)‐propranolol>(±)‐sotalol>(±)‐propranolol>(±)‐practolol, and for heart rate: (±)‐pindolol>(±)‐procinolol>(±)‐propranolol>(±)‐sotalol>(±)‐propranolol>(±)‐practolol.
(±)‐Sotalol, (±)‐pindolol and (±)‐procinolol‐induced changes in airway resistance and heart rate reached plateau values, which were not modified by increasing the dose. Since sotalol and procinolol have only very weak partial agonist and cardiac depressant properties, it appears that these changes can mainly be accounted for by the suppression of sympathetic tone. It is probable that this is also the case with pindolol.
On the other hand, (±)‐propranolol and (±)‐propranolol induced dose‐related changes in airway resistance and heart rate. Thus, a direct and nonspecific effect of both drugs on the bronchial muscle, similar to that observed on the heart appears to be implicated, together with sympathetic tone suppression in these variations.
(±)‐Practolol‐induced effects on airway resistance and heart rate were different from those observed with the five other β‐adrenoceptive antagonists.