bluuebunny/crossref_metadata_2025_split huggingface dataset:
Pyramidal Effects on Lumbo‐Sacral Internewones Activated by Somatic Afferents
Authors: Lundberg A. , Norrsell U. , Voorhoeve P. 
Published: December 2008

AbstractIntracellular recording was made from 23 interneurones in the dorsal horn and intermediate region. Stimulation of the sensorimotor cortex evoked excitatory postsynaptic potentials in interneurones receiving excitatory action from: 1) group I muscle afferents, 2) flexor reflex afferents, 3) cutaneous afferents. In a few of the interneurones the latency was so brief as to suggest a monosynaptic connexion from the pyramidal tract. Stimulation of the sensorimotor cortex evoked inhibitory action only in one interneurone, which received inhibitory action from the periphery as well. The findings are discussed mainly in relation to facilitatory actions evoked by volleys in the pyramidal tract on paths from primary afferents to motoneurones.
Fluorimetric Determination of 3‐O‐Methylated Derivatives of Adrenaline and Noradrenaline in Tissues and Body Fluids
Authors: Häggendal Jan 
Published: December 2008

AbstractA method for the determination of small amounts of metanephrine and normetanephrine in tissues and body fluids is described. The disturbing effect of adrenaline and noradrenaline is eliminated in two alternative ways: 1. By differential oxidation and subsequent ion exchange chromatography, 2. by separation on an ion exchange column. Metanephrine and normetanephrine are determined in the eluate from the ion exchange column according to the principles of the trihydroxyindole method for the fluorimetric determination of adrenaline and noradrenaline. Applications of the method on urine and brain tissue extracts are described.
Circulatory Studies in Well Trained Athletes at Rest and During Heavy Exercise, with Special Reference to Stroke Volume and the Influence of Body Position
Authors: Bevegård By S. , Holmgren A. , Jonsson B. 
Published: December 2008

AbstractEight well trained athletes (cyclists) with large dimensions of the circulatory system were studied with heart catheterization at rest and during exercise at 800 and 1,600 kpm/min both while sitting and supine. The results are compared with data from non‐athletes. The cardiac output at rest and during work showed the same relation to the oxygen uptake as in nonathletes. The cardiac output was less in the sitting than in the supine position by 2.6 1/min at rest and 1.8 1/min during heavy work, due to a smaller stroke volume in the sitting position in both groups. On transition from rest to exercise the stroke volume increased 9 % in the supine and 48 % in the sitting position. After these initial changes the stroke volume remained constant during continued exercise with the heavier load in both body positions. The difference in stroke volume between supine and sitting position averaged 43 ml at rest and 9 ml during heavy exercise. The stroke volume during work in the supine position showed the same relation to the blood volume as in the nonathletes. The stroke volume was larger than expected from the size of the heart, when compared with the previously demonstrated relationship in nonathletes. The rate of work, performed at pulse rate 170, bore approximately the same relationship to the stroke volume during exercise in both groups. The larger oxygen transport capacity of these athletes as compared to nonathletes is explained by a larger stroke volume. During exercise the ventricular filling pressures were higher than in nonathletes.
Some Effects of Vitamin D and Parathyroid Hormone on the Calcium and Phosphorus Metabolism of Bone in Vitro
Authors: Nichols By George , Schartum Stein , Vaes Gilbert M. 
Published: December 2008

AbstractThe influence of Vitamin D on serum calcium levels cannot be explained by the effect on intestinal absorption of calcium alone. Rather, some alteration in the distribution of calcium between bone and the circulating fluids must occur, a concept that has received in‐direct experimental support. In the study reported below bone (calvaria from mice) was incubated in vitro until a steady‐state equilibrium for calcium and phosphorus between the bone and the incubating fluid was reached, thus at the end of the incubation simulating the situation in vivo. The concentrations of these ions that bone from animals pre‐treated with Vitamin D maintained in their surrounding fluids were significantly higher than Vitamin D deficient controls demonstrating directly the calcium‐mobilizing effect of the vitamin. Further, Vitamin D increased the passive solubility of the bone mineral and lactate production by bone cells, suggesting modifications of bone cell metabolism. In the absence of Vitamin D, parathyroid hormone had the same effects as reported for the vitamin, indicating that the function of parathyroid hormone is independent of the presence of Vitamin D. Some evidence is presented that in mice deprived of Vitamin D secondary hyperparathyroidism exists.
Acetoin as a Metabolite of Ethanol
Authors: Hassinen By Ilmo 
Published: December 2008

AbstractBlood acetoin concentrations in rabbits were followed after administration of ethanol to animals receiving disulfiram and to control animals. Disulfiram increased blood acetoin before and after the administration of alcohol. No increase was observed in animals receiving alcohol alone. Acetoin formation from acetaldehyde and pyruvate or ethanol and pyruvate was investigated in vitro. In liver homogenates and minced liver acetoin was formed from ethanol and pyruvate, but not from ehtanol or pyruvate alone. Disulfiram inhibited acetoin synthesis from theanol and pyruvate under aerobic conditions, but not anaerobically or when acetaldehyde and pyruvate were used as substrates. The role of acetoinin alcohol metabolism and disulfiramalcohol reaction is discussed.
Birefringence of Isolated Muscle Fibres in Twitch and Tetanus
Authors: Eberstein By Arthur , Rosenfalck Annelise 
Published: December 2008

AbstractThe photoelectric measurement of changes in birefringence in single frog muscle fibres during isometric contraction is described. Birefringence, mechanical tension and intracellular action potential were recorded simultaneously. During a twitch birefringence decreased before tension was developed and reached minimum before tension reached maximum. The decrease in birefringence was 9 per cent at equilibrium length; at greater lengths the change in birefringence was less, as was twitch tension, but even when the sarcomeres were stretched to 3.6 and 3.8 μ a decrease in birefringence occurred. Double‐peak changes in phase difference, which have been described in whole muscle during isometric twitches, were not observed unless the fibre twisted in the light path. The decrease in birefringence was the same during twitch and tetanus. The decrease in birefringence during contraction may be due to an increase in the number of cross‐links between minute structural elements, or to a displacement of water within the fibre.
Slow and Fast Muscle Fibres in the Atlantic Hagfish (Myxine Glutinosa)
Authors: Andersen By P. , Jansen J. K. S. , Løyning Y. 
Published: December 2008

AbstractThe two histologically different types of muscle fibres in the parietal muscle of the hagfish have been studied by means of internal micro‐electrodes and by recording the mechanical response after stimulation of their motor nerves. The one type of fibre gives rapid twitch contractions of about 150 msec duration while those of the other type last more than 500 msec. Accordingly, the muscle fibres are called fast and slow respectively. The resting membrane potentials of the fast fibres were 74.6 mV (S. E. 0.3), that of the slow fibres 46 mV (S. E. 0.5). Indirect stimulation of the fast fibres evoked a characteristic focal end‐plate potential in one end of the fibre. The end‐plate potential gave rise to a conducted action potential with overshoot. The fast fibres appear to be innervated with only one motor axon each. In the slow fibres distributed junction potentials were obtained on indirect stimulation. The time course of the junction potentials varied, partly on account of local spike activity. On repetitive stimulation of slow fibres a plateau depolarization was reached which only moderately exceeded the peak of a single junction potential. The slow fibres are usually innervated with two motor axons reaching the fibre from each end.
Determination of Acetylcholinesterase Activity in Nor and Denervated Sympathetic Ganglia of the Cat. A Biochemical and Histochemical Comparison
Authors: Holmstedt B. , Lundgren G. , Sjøqvist F. 
Published: December 2008

AbstractAcChE was determined in normal and preganglionically denervated sympathetic ganglia with a titrigraphic method. The superior cervical, stellate, 7th lumbar and 1st sacral ganglia showed higher AcChE activities than the remaining paravertebral ganglia. Especially low AcChE values were obtained in the prevertebral ganglia. In denervation experiments a considerable decrease in AcChE activity was noted. The remaining activity was proportional to the number of histochemically heavily stained cell bodies in the ganglia investigated. Whereas ganglia containing many such cells retained 50% of their total AcChE activity after denervation (L7 and S1), the corresponding figure for ganglia almost lacking them was about 20% (superior cervical ganglion). Thus, some cells in the sympathetic system, showing intense histochemical staining possess significantly higher AcChE activities than the remaining ones as determined biochemically. These cells have been linked to a peripheral cholinergic function. Small traces of AcChE are found in adrenergic as well as sensory ganglion cells. The data presented fit in with the classical concept about the sympathetic system being composed of predominantly adrenergic cells with a few cholinergic ones concentrated in special relay stations.
Studies on the Relationship Between Flow Resistance, Capillary Filtration Coefficient and Regional Blood Volume in the Intestine of the Cat
Authors: Folkow By Björn , Lundgren Ove , Wallentin Ingemar 
Published: December 2008

AbstractFolkow, B., O. Lundgren and I. Wallentin. Studies on the relationship between flow resistance, capillary filtration coefficient and regional blood volume in the intestine of the cat. Acta physiol. scand. 1963. 57. 270—283. — The relation between flow resistance, regional blood volume and capillary filtration coefficient (CFC) in the cat's intestine has been quantitatively studied at different levels of vascular smooth muscle activity, and compared to the vascular bed of the skeletal muscles. The resistance vessels of booth these vascular circuits maintain a considerable ‘basal tone’, but the intestine is far richer vascularized, which is obvious from the figures given for flow resistance, regional blood volume and CFC at comparable levels of vascular tone, including maximal vasodilatation. Intestinal CFC is both in absolute and relative terms higher than in the skeletal muscles, as reflected by a definitely larger CFC/blood flow ratio over the entire range of vascular tone. CFC thus increases considerably when vascular tone is reduced and reaches very high figures at maximal vasodilatation. This is thought to reflect an opening up of additional capillaries due to relaxation of their ‘precapillary sphincters’. Reasons arc given for the belief that the glandular mucosal portion is far better vascularized than the smooth muscle portion of the intestine and at maximal vasodilatation CFC of the mucosal portion may be of the order of 1 ml/min Hg/mm/100 g of tissue. Such a figure is in fact comparable to the renal glomerular filtration, when expressed in the same way.
Exchange of Phosphate‐Groups between Inorganic Phosphate and Adenosine Triphosphate in Red Blood Cells
Authors: Verdier Carl‐Henric de 
Published: December 2008

AbstractIn hemolysates of human red blood cells there is a rapid exchange of phosphate groups between inorganic phosphate and the terminal phosphate group of adenosine triphosphate. The exchange is dependent upon the phosphoglyceraldehyde dehydrogenase and the phosphoglyceryl kinase reactions since phosphoglyceraldehyde, 3‐phosphoglycerate and DPN are essential for the exchange reaction. The implication of this finding is that studies of the incorporation of inorganic labelled phosphate into different compounds of the erythrocyte cannot in general be used to draw conclusions about the glucose metabolism of red cells.
The Participation of Bone in the Sodium and Potassium Metabolism of the Rat. II The effect of variation of electrolyte intake, acidosis and alkalosis
Authors: Norman N. 
Published: December 2008

AbstractRats were examined according to a previously described technique Norman 1963) permitting the simultaneous measurement of total exchangeable sodium and potassium in their body as well as the total and exchangeable concentration of sodium and potassium in their skeleton. The effect of various combinations of sodium depletion, potassium depletion, sodium loading, acidosis and alkalosis was studied. Simple sodium depletion caused a loss of 10 per cent of body sodium, 90 per cent of the loss was accounted for by shrinkage of the extracellular fluid volume. When acidosis was induced in addition, sodium was given off from the exchangeable bone sodium fraction. Potassium depletion caused a picture similar to that of starvation. The potassium depleted rats had a greatly reduced ability to handle a metabolic alkalosis. The participation of bone sodium and potassium in the metabolism of the rats was smaller than found by others. The mean difference from maximum storage of sodium in alkalosis, to maximum depletion in acidosis, corresponded to 10 per cent of the total bone sodium concentration. Bone potassium concentration showed great constancy, with no parallel to the variations in bone sodium.
Behaviour and Monoamine Levels During Long‐Term Administration of Reserpine to Rabbits
Authors: Häggendal By Jan , Lindqvist Margit 
Published: December 2008

AbstractRabbits were injected with reserpine (0.1 and 0.2 mg per kg subcutaneously) daily for weeks. Noradrenaline, dopamine, and 5‐hydroxytryptamine were determined in the brain, nor‐adrenaline in the heart, and adrenaline in the adrenals. Most of the monoamines disappeared from the tissues during the first few weeks. Almost normal behaviour was observed in animals with very low monoamine levels. Thus the major part of the monoamine stores could be removed with but slight functional changes. The data suggested, however, a correlation between the remaining small fraction and behaviour.
Differentiated Effects on Certain Blood‐Brain Barrier Phenomena and on the EEG Produced by Means of Intracarotidally Applied Mercuric Dichloride
Authors: Flodmark S. , Steinwall O. 
Published: December 2008

AbstractIn a previous paper a method was described for correlative studies of EEG and blood‐brain barrier phenomena under conditions facilitating separate effects on either parameter. In the present experiments this method was employed in order to study the influence on the EEG of a slight but persistent barrier dysfunction. The barrier was impaired by means of intravasal application of weak solutions of HgCl2 (0.01—0.04 mM) within one hemisphere. It was found that this type of barrier damage, revealed by unilateral invasion in the brain of normally barred acid dyes and related organic anions, could exist without significant influence on the EEG for periods of variable duration, from a few minutes up to more than 2 hours. Ultimately, however, the electrical activity of the damaged hemisphere deteriorated. It was concluded that the strong tissue affinity of mercuric ions might favour a restriction of their action within “barrier structures” interposed between blood and neurons in this type of experiments. The cumulative disturbances in the metabolic milieu of the neurons arising from the persistent barrier dysfunction might sufficiently explain the terminal EEG deterioration, although a direct action of the mercurial on the neurons could not be ruled out.
Effect of Hydrazides on Liver Alanine and Aspartate Transaminases and Lactate Dehydrogenase in Developing Chick Embryos1
Authors: Koivusalo Martti , Penttilä Ilkka , Raina Aarne , Tenhunen Raimo 
Published: December 2008

AbstractAminoguanidine (5 μmoles/embryo), isoniazid (5 μmoles/embryo), iproniazid (5 μmoles/embryo), isocarboxazid (3 μmoles/embryo), nialamide (5—15 μmoles/embryo) and 4‐deoxypyridoxine (10—30 μmoles/embryo) decreased liver aspartate transaminase activity but increased liver alanine transaminase activity in chick embryo in vivo. This effect was of long duration, after a single dose (5 μmoles) of nialamide or isoniazid it lasted at least 70 hours. Liver lactate dchydrogenase activity was significantly decreased only after 15 μmoles of nialamide per embryo. A temporary increase in liver α‐ketoglutaric and pyruvic acid content was seen after 15 μmolcs of nialamide. In rats nialamide had no effect on liver transaminase activities.
Biotinidase Activity in Animal Tissues
Authors: Koivusalo Martti , Pispa Jaakko 
Published: December 2008

AbstractKorvusalo, M. and J. Pispa. Biotinidase activity in animal tissues. Acta physiol. scand. 1963. 58. 13—19. — Biotinidase activity of human serum and rat, guinea pig and rabbit serum, liver and intestine was determined using biocytin as substrate. The biotinidase activities of human serum and rat serum and tissues were of the same magnitude, in guinea pig serum the activity was about 10 per cent and in rabbit serum only 1 per cent of the activity in human and rat sera. Similar although less marked differences were found in the biotinidase activity of rat, guinea pig and rabbit tissues. The biotinidase activity of human and rat sera was inhibited by p‐chloromercuribenzoate, arsenite and monoiodoacetate; it was slightly stimulated by glutathione. Ethy‐lenediamine tetraacetate and cyanide had no effect. In zone electrotrophoresis the human serum biotinidase activity had slightly smaller mobility at pH 8.6 than albumin, and moved as a single peak.
Effects of ACTH on Erythropoiesis in the Rabbit
Authors: Halvorsen S. 
Published: December 2008

AbstractHalvorsen, S. Effects of ACTH on erythropoiesis in the rabbit. Acta physiol. scand. 1963. 58. 30—39. — Hypothalamic stimulation increases erythropoiesis in intact rabbits (Seip, et al. 1961). In order to compare the effect of hypothalamic stimulation on erythropoiesis with the effect of ACTH, daily ACTH injections have been given to intact rabbits and the changes in erythropoiesis have been followed with the same parameters as in the previous study. ACTH injections for 2 and 4 weeks increased the red cell mass 11.2 and 27.7 per cent, and the red cell mass per kg body weight 6.3 and 23.3 per cent, respectively. The reticulocytes increased slightly, but significantly. These findings confirm previous observations in other species that ACTH stimulates erythropoiesis in intact animals. The hematological changes seen in the ACTH injected rabbits did not correspond quantitatively to the changes seen following hypothalamic stimulation. It is concluded that the previously reported effect of hypothalamic stimulation on erythropoiesis is not due to increased ACTH production alone.
Blood Flow in the Avian Salt Gland Studied by Polarographic Oxygen Electrodes
Authors: Fänge R. , Krog J. , Reite O. 
Published: December 2008

AbstractFänge, R., J. Krog and O. Reite. Blood flow in the avian salt gland studied by polarographic oxygen electrodes. Acta physiol. scand. 1963. 58. 40—47. — The blood flow in the salt gland of the duck (Anas platyrhynchus) and gulls (Larus argentatus, L. fuscus) was studied by means of polarographic oxygen electrodes. A vasodilatation occurs during and after secretion caused by parasympathetic nerve stimulation. It is probably mediated by both neural and humoral mechanisms. The cervical sympathetic trunk carries vasoconstrictor fibres to the gland. Acetylcholine, histamine and isoproterenol give vasodilatation, while adrenaline, noradrenaline and serotonin have a constrictory influence.
Catecholamine Excretion and Personality Traits in Paratroop Trainees
Authors: Bloom G. , Euler U. S. v. , Frankenhaeuser M. 
Published: December 2008

AbstractBloom, G., U. S. v. Euler and M. Frankenhaeuser. Catecholamine excretion and personality traits in paratroop trainees. Acta physiol. scand. 1963. 58. 77—89. — The excretion of adrenaline and nor‐adrenaline in urine was measured in paratroop trainees and officers during night rest, ground training and during 2—3‐hour periods under which jumps were performed from training tower and from aircraft. The mean adrenaline excretion in the trainees was 3.3 ± 0.5 ng/min during night rest and 8.8 ± 1.0 ng/min during ground activity. For periods including jumps, mean adrenaline excretion was significantly increased to values of 17.4—19.9 ng/min. The mean noradrenaline excretion was 11.2 ± 2.0 ng/min during night rest, 23.6 ± 2.6 ng/min during ground activity and 21.1—38.1 ng/min in periods under which jumps were performed. No difference in catecholamine excretion values was observed between officers and trainees. Increased pulse rates were noted during preparatory procedures preceding a jump, and lowered blood eosinophil levels observed after the 1st parachute jump. Within the present small sample of subjects it was not possible to obtain reliable coefficients of correlation between basic personality traits and excretion of adrenaline and noradrenaline, but some of the rating techniques used for assessing personality traits proved highly reliable and, hence, well suited for future research in this area.
The Physiology of the Swimbladder of the Eel Anguilla vulgaris: I. The solubility of gases and the buffer capacity of the blood
Authors: Steen Johan B. 
Published: December 2008

AbstractSteen, J.B. The physiology of the swimbladder of the eel, Anguilla vulgaris. I. The solubility of gases and the buffer capacity of the blood. Acta physiol. scand. 1963. 58. 124–137. — Some physiological properties of eel blood which may have importance in gas exchange in the swimbladder have been investigated. Using the Scholander and Roughton syringe analyzer for blood gases and micromethods for determination of lactic acid and pH the solubility of the gases of air has been measured at various temperatures and pH levels at pressures up to 1 atm. The buffer capacity of eel blood has also been studied in some detail. The O2‐ and CO2‐solubility followed the same general pattern as is known to obtain in blood of other species. The O2‐content of blood at a pO2 of I atm is reduced by about 40% when the pH is lowered from arterial values to 7.0. The N2 and Ar solubility is approximately 10% reduced when the pH of eel blood is lowered from about 7.8 to 7.5. Using the same experimental technique no such effect was found on eel plasma, blood from man, trout or cod.