bluuebunny/crossref_metadata_2025_split huggingface dataset:
Release and Uptake of Noradrenaline in Adrenergic Nerve Granules
Authors: Euler U. S. Von 
Published: December 2008

AbstractA brief review is given of some recent findings concerning noradrenaline (NA)1release and uptake in isolated nerve granules and in connection with neurotransmissionin vivo.The main results are summarized in the following points. Rabbit heart granules have similar NA release rate and other properties as bovine nerve granules. Granules from the bovine vesicular gland show about 3 times lower NA release rate and differ in other respects from splenic nerve granules. Tyramine inhibits the uptake of NA in partially depleted isolated splenic nerve granules. Adrenergic a‐ and β‐blockers lower the NA release rate and inhibit NA uptake in splenic nerve granules, suggesting common features of the “receptor” mechanisms in granules and effector cells. Intermittent sympathetic nerve stimulation in decaborane depleted rabbits causes transmission failure which is partially overcome by “neuronal rest” and injection of NA or dopamine. Although homogenization experiments indicate that most of the NA in axones and nerve endings occur in granule bound form it is assumed that part of the NA is present as “transport NA” in loosely bound form available for immediate release.
Studies of Noradrenaline Biosynthesis in Nerve Tissue
Authors: Stjärne L. 
Published: December 2008

AbstractResults recently obtained in studies of the invitrosynthesis of noradrenaline from tyrosine, dopa and dopamine in various fractions of the bovine splenic nerve homogenate are reviewed. It is concluded that the first two steps in noradrenaline synthesis take place extragranularly, while the last step, the β‐hydroxylation of dopamine, occurs in the granules. Evidence is presented that noradrenaline synthesis may be feed‐back regulated, not only extragranularly by product inhibition of the hydro‐ xylation of tyrosine, but also at the granule level, by competitive inhibition of dopamine penetration to the β‐hydroxylation sites. The newly synthesized noradrenaline appears to be stored separately from the major endogenous noradrenaline store, in a compartment of limited capacity, possibly located in the granule membrane. This membrane appears to have a limited permeability to amines, the passage of tracer amounts of amines being competitively inhibited both by dopamine or noradrenaline in the medium, and by reserpine. Studies of the “wash fraction” in these experiments support the concept that deamination to a large extent occurs in the “granule fraction”, which according to morphological evidence appears to be largely free from contamination with mitochondria. This suggests that monoamine oxidase may be located not only in mitochondria, but also in the noradrenaline storing granules themselves. The results also suggest the existence of several distinct “pools” of noradrenaline in the preparation. The possibility is discussed that monoamine oxidase may attack only one of these “pools”, the non‐bound intragranular amines, while the amines in the remaining “pools” may be protected against this enzyme, either by binding or by staying extragranularly. The results are summarized diagrammatically in a proposed model of the sympathetic neuro‐effector junction.
Mode of Storage of Histamine in Mast Cells
Authors: Thon I. L. , Uvnäs B. 
Published: December 2008

AbstractHistamine containing granular material was collected from water lysed peritoneal rat mast cells. The histamine was observed to be released in the presence of cations. A re‐uptake of the amine occurred on suspension of depleted granular material in histamine containing solutions. Release as well as uptake of histamine occurred rapidly at 0°C. The results are in accordance with the idea that histamine is electrostatically bound to a granular protein‐heparin complex, the release and uptake of the amine being a physical process depending on the extra‐ and intra‐granular concentration ratios of histamine and cations.
Biochemical and Histochemical Studies on the Effects of Imipramine‐like Drugs and (+)‐Amphetamine on Central and Peripheral Catecholamine Neurons
Authors: Carlsson Arvid , Fuxe Kjell , Hamberger Bertil , Lindqvist Margit 
Published: December 2008

AbstractRats were depleted of tissue monoamines by reserpine treatment and were then treated with a monoamine‐oxidase inhibitor (nialamide). Subsequent injection of l‐dopa caused accumulation of dopamine (DA) and noradrenaline (NA) in brain and heart, as well as restoration of the specific histochemical catecholamine (CA) fluorescence in DA and NA nerve fibres. CA accumulation and fluorescence restoration in central and peripheral NA fibres could be largely prevented by the anti‐depressive agents desipramine and protriptyline and — in peripheral tissues only — Lu 3–010. No effect on DA fibres was observed. In‐vitro studies on tissue slices showed a blocking action of these drugs, when added to the medium, on amine uptake by central and peripheral NA fibres, but no effect on amine uptake by DA fibres. When administered to the animals before the in‐vitro experiment, desipramine was active on both central and peripheral NA fibres, Lu 3–010 on peripheral NA fibres only. In similar in‐vivo experiments (+)‐amphetamine was found to largely prevent NA accumulation, to lower the ratio of DA to its metabolite 3‐methoxytyramine, and to largely prevent the restoration of CA fluorescence in both NA and DA fibres. In‐vitro studies showed that (+)‐amphetamine was able to block amine uptake by both NA and DA fibres. The cortical NA fibres were particularly sensitive to (+)‐amphetamine, in vivo and in vitro. — In rats pretreated with nialamide only, (+)‐amphetamine promoted the accumulation of O‐methylated basic CA metabolites and reduced specific fluorescence in central non‐terminal CA axons.It is concluded that desipramine and protriptyline are able to block the reserpine‐resistant amine‐ concentrating mechanism of central and peripheral NA, but not DA fibres, whereas (+)‐amphet‐ amine appears to cause release of amines from extragranular locations within both NA and DA fibres.
Microspectrofluorometric Identification of Metaraminol in Sympathetic Adrenergic Neurons
Authors: Jonsson Gösta , Ritzén Martin 
Published: December 2008

AbstractBy means of fluorescence microspectrophotometric techniques, it has been possible to demonstrate uptake and accumulation of injected metarminol and a‐methyl‐m‐tyrosine within the adrenergic neuron with and without reserpine pretreatment. The investigation was based on an earlier observation that m‐hydroxyphenylethylamines in a dried protein layer condense with formaldehyde forming fluorescent 6‐hydroxy‐isoquinolines. This reaction is quite analogous to that between formaldehyde and biogenic monoamines used for the histochemical demonstration of these amines according to the method of Falck and Hillarp. Thus appearance of characteristic blue fluorescence (max. at 415 mμ) due to presence of metahydroxy compounds with simultaneous disappearance of the specific catecholamine fluorescence (max. at 470 mμ) could be seen to follow administration of metaraminol and a‐methyl‐m‐tyrosine. The blue fluorescence of the metahydroxy compounds explains earlier failures to visualize these amines intraneuronally with the secondary filters used (strong absorption below 480 mμ). Parallelly performed model experiments with m‐hydroxyphenylethylamines and specificity tests confirmed the identity of the fluorescence observed in the adrenergic neurons.
Effect of Phenoxybenzamine and Hydergine on Urinary Gatechol Amines in Rats during Restraint
Authors: Graham Lindsay A. 
Published: December 2008

AbstractThe technique of restraining rats in wire mesh was used to study urinary catechol amine excretion under stress. Rats restrained for 12 and 16 hrs excreted higher amounts of both A and NA than did free animals. Rats pre‐treated with phenoxybenzamine 10 mg/kg excreted more A and NA than did control animals, and these differences were pronounced during restraint. PBA appears to interfere with either binding of NA at the receptor site, or with its destruction, possibly in the liver or with re‐uptake. Hydergine 1 mg/kg did not alter the resting excretion of A or NA but increased the output of A in urine during restraint.
Surface Properties of Lung Extracts
Authors: Adams Forrest H. , Enhörning Goran , Regné‐Karlsson Maud 
Published: December 2008

AbstractSurface properties of washings and extracts from fetal guinea pig lungs were investigated with the dynamic alveolar model previously described (Adams and Enhörning 1966). The fetuses were of various stages of gestation with weights ranging from 2.2 to 135 g. It was found that: 1. Lung extracts showed more surface activity than did lung washings. 2. Surface tension decreased with time. 3. Stability index and phase difference, reflecting viscosity of the bubble film, increased with time. After 2 min the mean values were significantly higher in lung extracts from fetuses weighing more than 60 g than in lung extracts from fetuses weighing less.—Thus, after only 2 min of measurement and with a small sample (0.2 ml) the method makes it possible to differentiate immature from more mature lung surface properties. The method might also make it possible to differentiate normal infants from those who subsequently develop idiopathic respiratory distress by examining the fluid obtained by aspiration of the upper airways.
A Method for Intracardiac Recording of Monophasic Action Potentials in the Dog Heart in Situ
Authors: Sjöstrand Ulf 
Published: December 2008

AbstractA technique for intracardiac recording of monophasic action potentials has been developed and some results are presented. The method appears to provide the requirements for extended studies of excitation, rhythmicity and impulse propagation in the heart in situ in both man and lower animals, and gives recordings which can be correlated in time with the conventionally recorded electrocardiogram. The method allows recording of the electrical activity in subendocardially situated atrial and ventricular muscle as well as in subendocardially situated parts of the conducting system; with further development of this method it should be possible to study changes in the amplitude, form and duration of the action potential.
Studies on Adrenergic and Gholinergic Receptors in the Isolated Hearts of Lampetra fluviatilis (Cyclostomata) and Pleuronectes platessa (Teleostei)
Authors: Falck B. , Mecklenburg C. von , Myhrberg H. , Persson H. 
Published: December 2008

AbstractAn attempt has been made to characterize the adrenergic and cholinergic receptors in the isolated hearts of the lamprey Lampetra fluviatilis and the plaice Pleuronectes platessa. In both species hearts respond to adrenaline, noradrenaline and isoprenaline in the same way as the isolated mammalian heart and the effect of these agents is blocked by a β‐receptor blocking agent. The adrenergic receptors thus are of the β‐type. The cholinergic receptors are different in the heart of the two species. In the lamprey heart the cholinergic receptors are of the curaresensitive type and these receptors seem to be the only existing type of cholinergic receptors in the heart of this species. In the plaice heart, however, the cholinergic receptors are of the same nature as in the mammalian heart i.e. of the hexamethonium and the atropine sensitive type. The effects of nicotine and tyramine on the isolated lamprey and plaice hearts have been discussed with regard to the existence and localization of catecholamines in the hearts of these species.
Motor Deficits after Transsection of a Bulbar Pyramid in the Cat
Authors: Laursen Arne Mosfeldt , Wiesendanger Mario 
Published: December 2008

AbstractThe aim of the study was to determine whether the extended position of freely hanging limbs contralateral to transsection of one pyramid in cat is due to extensor hypertonia or deficient flexor reflexes and to determine the duration of motor defects produced by unilateral pyramidotomy. The posture was due to absence of activity in contralateral flexors; action potentials in extensors were absent both on the operated and unoperated side. Placing reactions were delayed or absent in contralateral limbs, struggling was diminished and there was a tendency for the paws to remain in awkward positions. After one month operated cats could be distinguished from unoperated cats only by diminished flexor reflexes in contralateral legs and by a slight delay in contact placing. Damage of the medial lemniscus produced the tendency to place contralateral paws in awkward positions lasting for one week. Unlike pyramidal section, lemniscal damage did not produce deficient flexor reflexes.
Insulin Binding Proteins in Normal Serum. The in vitro Association of Homologous125I Labelled Insulin and Normal Serum Proteins
Authors: Gjedde F. 
Published: December 2008

AbstractBy incubation in vitro of normal human serum with 126I labelled insulin, association of radioactivity with serum protein fractions was demonstrated. Previous findings of an association with two macroglobulins were confirmed and an association with a third fraction observed. The macro‐globulins were identified as alpha‐2‐M and beta‐2‐M globulin by starch gel electrophoresis, immunoelectrophoresis, chromatography on Sephadex G 200, immunoprecipitation with specific antisera and precipitation with ammoniumsulphate and trichloroacetic acid. The third serum protein fraction was characterized by starch gel electrophoresis as an alpha‐one globulin migrating immediately behind albumin. By gel filtration it was eluted with albumin and it was soluble in 80 % ammonium sulphate, but completely precipitated by tricholoracetic acid and by Rivanol. The proportion of the radioactivity incorporated into the three fractions was independent of the amount of insulin present but proportional to the duration of the incubation. The results indicate that the incorporation of radioactivity into the alpha‐2‐M and alpha‐one globulin continues throughout the incubation period with a constant rate of 1 and 0.5 per cent per 24 hrs respectively, except [or a rapid initial association of approximately 4 per cent to the alpha‐one globulin. In contrast, the incorporation into the beta‐2‐M globulin reaches a constant level within the first week. About 10 per cent of the radioactivity in the macroglobulin fraction and 32 per cent of that in the alpha‐one globulin fraction could be precipitated by immunoprecipitation for insulin.
Heart Volume during Prolonged Exercise in the Supine and Sitting Position
Authors: Ekelund L.‐G. , Holmgren A. , Ovenfors C. O. 
Published: December 2008

AbstractThe roentgenological heart volume was studied in 10 healthy young men during prolonged continuous exercise of constant intensity in the sitting position and in 6 subjects also in the supinr position. The work load was on an average 760.0 kpm/min in the sitting and 758.3 kpm/min in the supine position. The heart rate in the sitting position after 3–9 min exercise was 139.5 beats/min and 171.0 beats/min at the end of work, mean work time 56.5 min. The corresponding figures in the supine position were 127.8 and 156.7 beats/min, with a mean work time of 64.0 min. The exposure of the roentgen film was made in end‐diastole. During the continuous exercise at a constant load there was a continuous fall of the heart volume in both body positions accompanied by a continuous increase in heart rate. There Lvas a significant regression of total heart volume on heart rate. The rate of change in heart volume was 37.5 ml and 58.3 ml per 10 beats/min change in heart rate in the sitting and supine positions respectively. The maximum decrease was on an average 81.1 ml and 110.5 ml with an increase in heart rate of 28.6 beats/min and 24.8 beats/min in the sitting and supine position respectively. Close to exhaustion, the heart volume increased in 6 of 10 subjects in the sitting position by, on an average, 52.5 ml (probably significant) and in 3 of 6 in supine by. on an average, 42.0 ml in spite of a further increase in heart rate.
Relationship Between Ventricular Pressures and Right and Left Myocardial Blood Flow
Authors: Auklndd Knut , Kiil Fredrik , Kjekshus John 
Published: December 2008

AbstractThe effects of constriction of the pulmonary artery and aorta on myocardial blood flow, measured as local hydrogen clearances, in the anterior parts of the right and the left myocardium have been studied in open chest dogs. The increase in myocardial flow that by progressive constriction rarely exceeded 100 percent of control values was in most experiments confined to the ventricle‐ under increased pressure load. Plots of relative flows and pressures yielded regression lines of similar slopes for both ventricles without significant differences between systolic and mean ventricular pressures as indices of myocardial flow. Left myocardial flow remained unchanged when outflow resistance from the right ventriclc incrcased until aortic pressure fell. The effect of increased aortic pressure on right myocardial flow was more variable. Increase of systolic left ventricular pressure to 250 mm Hg. had slight or no effect on right myocardial flow. More severe aortic constriction which donbled mean left ventricular pressure increased right and left myocardial flow similarly. It is concluded that the relationship between relative flow and ventricular pressure variations previously demonstrated fur the left ventricle also applies to the right ventricle and that myocardial flow is regulnted independently for the two ventricles. except at extreme perfusion pressures.
Effect of Prolonged, Heavy Exercise on Urinary Protein Excretion and Plasma Renin Activity
Authors: Božovć Ljubomir , Castenfors Jan , Piscator Macnus 
Published: December 2008

AbstractExperimentally induced proteinuria by renin injection is a well‐known phenomenon. The aim of this investigation is to study the effect of prolonged, heavy, muscular exercise on plasma renin activity and its possible connection with exercise proteinuria. In a group of 15 male participants in theVasaloppetin 1965 (85 km ski race) the urinary protein excretion was studied before and during the ski race, and the plasma renin activity at the start and the end of the race. The increase both in plasma renin activity and in urinary protein excretion was statistically significant. During rest, before the ski race there was a significant correlation between plasma renin activity and protein excretion in the urine (r = 0.84), but not during the ski race.
In vitro Assay of the Effect on Bone Marrow Cell Proliferation of Factors in Serum from the Irradiated Rat
Authors: Cederberg A. , Niskanen E. , Rytömaa T. 
Published: December 2008

AbstractAn attempt was made to demonstrate the existence or non‐existence in rat serum of humoral factors which could be held accountable for the true regeneration process in the whole body irradiation‐damaged bone marrow cells. The effects of the test serum, collected at the time of onset of true regeneration (10 days after whole body irradiation of 600 r), were assayed in vitro, using normal bone marrow cells as target tissue. The results demonstrated that, on the average, the proportion of 3H‐thymidine labelled cells was about 24 per cent higher in cultures incubated in the presence of test sera than in the controls.On the basis of ‘partial’ differential counts (per cent mature granolcytes), and measurements of total radioactivities incorporated in the whole population of cells (both estimations being performed on some of the preparations also analysed by autoradiography), it was concluded that the effect of the WBI serum was due to one or more factors which convert resting progenitor cells to the generative cycle.
On the Firing Pattern of Spinal Neurones Activated from the Secondary Endings of Muscle Spindles
Authors: Jansen Jan K. S. , Nicolaysen Kåre , Rudjord Torstein 
Published: December 2008

AbstractSome properties of a group of spinal neurones with axons ascending in the dorsolateral funicle are reported. They are excited by muscle stretch, and pause during muscle contraction. Their threshold to electrical stimulation of the muscle nerve is in the group II range. Their latencies are greater than that of the group I activated units. Their firing frequency increases approximately linearly with muscle length. Their discharge pattern is characterizcd by a relatively high degree of regularity. It is suggested that they represent a system relaying information on the length of individual muscles or synergistic muscle groups to the brain.
Effect of Ethacrynic Acid on Plasma Renin Activity during Supine Exercise in Normal Subjects
Authors: Castenfors Jan 
Published: December 2008

AbstractPlasma renin activity, clearances of inulin(cin)and para‐aminohippuric acid(cpah), free water clearance(ch2o)and urinary excretion of sodium and potassium were measured in 6 normal subjects at rest and during exercise in the supine position on a bicycle ergometer. The mean work load was 667 kpm/min and the duration of exercise 45 min. Ethacrynic acid, 50 mg, was injected i.v. at the start of exercise. Ethacrynic acid did not influence the normally occurring decrease in Cpahand Cinduring exercise but abolished the renal concentration mechanism, indicating an inhibition of sodium reabsorption in the ascending loop of Henle. The urinary sodium cxcrction increased markedly, indicating an increased load of sodium in distal tubules. This was coincident with increased plasma renin activity. The findings indicate that changes in plasma sodium concentration or sodium load in the distal tubules are of minor importance for the increase in plasma renin activity during exercise.
The Role of Phosphorylase a and b for the Control of Glycogenolysis in the Isolated Working Rat Heart
Authors: ØYe Ivar 
Published: December 2008

AbstractGlycogen breakdown and lactate release have been related to the state of glycogen phosphorylase in the isolated, working rat heart under various experimental conditions. Increased work caused increased rate of glycogen breakdown despite low and constant levels of phosphorylase a. In the absence of added glucose, lactate release was small and unaffected by the work load imposed on the heart. Hypoxia caused a transient increase in the levels of phosphorylase a associated with increased lactate release. This effect of hypoxia was inhibited by the presence of the adrenergic beta receptor blocking agent propranolol and is explained as due to the release of adrenergic transmittor from local stores during hypoxia. Prolonged hypoxia and dinitrophenol caused a fall in the contractile activity and a fall in the levels of ATP. Under these conditions the hearts showed increased glycogenolysis and lactate release at subnormal levels of phosphorylase a. This is in accordance with the hypothesis that glycogenolysis under aerobic conditions is restricted by ATP‐inhibition of phosphorylase b. Although glycogenolysis can be regulated in vitro without participation of phosphorylase b to a transformation, the latter mechanism was found to be responsible for regulation of glycogenolysis during the early phase of hypoxia. This mechanism must be considered as most significant for the regulation of glycogen breakdown in vivo when the hearts are subject to adrenergic control.
Inhibition of Vagally Stimulated Gastric Secretion after Mucosal Mast Cell Degranulation
Authors: Hirvonen Jorma , Kamppuri Veijo , Rasanen Toimi 
Published: December 2008

AbstractTotal vagotomy was carried out on rats through laparotomy. and the peripheral end of the vagus was electrically stimulated for one hour after closing the ventricle with a Shay ligature. after the stimulation, the gastric fluid was collected, its volume, pH and concentration of free HCI were measured. Free HCl was secreted significantly less in the ventricles of rats whose mucosal mast cells had been degranulated by dexamethasone before the vagus stimulation, than in the rats not treated with dexamethasone.The importance of the synthesis and accumulation of histamine in the mast cells of the gnstrir mucosa as a peripheral link in the stimulatory chain of gastric secretion is discussed.