bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Further Analysis of the Neuromuscular Block Caused by dcetylcholine
Authors: THESLEFF BY STEPHEN 
Published: December 2008

Summary.The repolarization of the end‐plate region and the neuromuscular block caused in frog skeletal muscle by persisting high concentrations of acetylcholine could be due either to a niechanisni rrducing the reactivity of the end‐plate “receptors” without affecting the membrane. i. e. a tubocurarine‐like effect. or to the possibility that the membrane at the end‐plate region was left highly permeable to ions other than sodium.To determine which of these two alternative iriechanisms is lrsponsible for the effects of persisting concentrations of acctylcholine, determinations were made of the transverse electric. membrane resistance at the end‐plate region heforc and after the application of acetylcholine.It was shown that the transverse membrane resistance was completely normal when acetylcholine had caused a neuromuscular block and the end‐plate region was repolarized.This excludes the possibility that the repolarization of the end‐plate region with the neuromuscular block in the presence of persisting concentrations of acetylcholine is due to an increase in the ionic permeability of the muscle membrane. It is concluded that the only other known mode of action which could account for these effects of acetylcholine is that exerted hp tubocurarine.
The Effect of Anesthetic Agents on Skeletal Muscle Membrane
Authors: THESLEFF STEPHEN 
Published: December 2008

Summary.The action of pentobarbital sodium on neuromuscular transmission and the effects of pentobarbital, urethan, chloral hydrate, chloralose, paraldehyde and tribromethanol on skeletal muscle excitability has been investigated with the intracellular micro‐electrode technique in the isolated sartorius nerve‐muscle preparation of the frog.Pentobarbital sodium blocked neuromuscular transmission by rendering the end‐plate “receptors” unreactive to the depolarizing effect of acetylcholine.All agents caused an increase in the electric “threshold” of the muscle membrane and reduced or abolished the action potential. The rate of rise of an action potential was decreased by all agents.These effects occurred without significant changes in the resting membrane potential of the muscle fibre and without a decrease in the transverse electric resistance of the muscle membrane.On the basis of the ionic hypothesis for electric activity in nerve and muscle (Hodgkin and Katz 1949). it is suggested that these effects on the membrane “threshold” and on the action potential are due to a reduction of the selective sodium conductance change caused by an inactivation of the “sodium carrying mechanism” in the muscle membrane.A close relationship was observed between the hypnotic dose in the intact frog and the concentration of the respective agent that caused a reduction of the selective sodium conductance change in the frog skeletal muscle membrane.
Transcapillary Migrntion of Ethyl Alcohol in the Pulmonary Circulstion. A Method for Determining the Water Content of the Lungs in Vivo
Authors: ANTHONISEN POUL , CRONE CHRISTIAN 
Published: December 2008

Summary.A method is described for determining the extravascular water content of the lungs in living humans. The method is based on a determination of the amount of ethylalcohol lost from the capillary bed during the first circulation through the lungs. When the alcohol concentration of the extravascular water was also known, the space of distribution of alcohol could be calculated. There is reason to believe that the extravasculax alcohol space represents the total extravascular water content of the lungs.In 15 normal subjects the method showed a mean value of 515 ± 27 ml (S. E., n =15). Three experiments performed on the same subject showed a maximum deviation from the mean value of ± 10 per cent.The present investigation indicates that the total weight of the extravascular lung tissue is about 600 grams, and consequently the amount of blood in the capillaries and minor vessels of the lungs which is not lost at removal must be 300–400 ml.
Functional Organization of the Dorsal Spino‐Cerebellar Tract in the Cat.: V. Further Experiments on Convergence of Excitatory and Inhibitory Actions.
Authors: HOLMQVIST B. , LUNDBERG A. , OSCARSSON O. 
Published: December 2008

Summary.Intra‐axonal recording in Flechsig's fasciculus was used for a further investigation of the functional organization of the dorsal spino‐cerebellar tract.After ipsilateral section of lumbar and sacral dorsal roots, many neurons identified as belonging to the dorsal spino‐cerebellar tract (neurons activated by group I muscle afferents) were found to have a resting discharge. In silent neurons a discharge could be made to appear after repetitive stimulation of dorsal roots. It is concluded that these neurons receive excitatory action from interneurons.Convergence of excitation and inhibition onto DSCT neurons from various muscles was studied with the use of electrical stimulation of muscle nerves as well as with adequate activation of stretch receptors.As evidenced by monosynaptic excitation on single shock stimulation of muscle nerves, convergence of excitatory action mediated by group I afferents was found to be rather limited. A number of neurons can only be fired from one muscle nerve but some from as many as three out of seven nerves (including non‐synergists).Convergence of inhibitory action mediated by group I afferents is extensive also from other muscles than the antagonist of the nerve supplying the main excitatory action.
The Intestinal Absorption and Metabolism of Chimyl Alcohol in the Rat.
Authors: BERGSTRÖM SUNE , BLOMSTRAND ROLF 
Published: December 2008

Summary. Unanaesthetized rats provided with a thoracic duct fistula were fed [14C]‐labeled chimyl alcohol (α‐[1‐14C]‐hexadecylglyceryl ether) dissolved in olive oil.The labelled chimyl alcohol was absorbed to 95 per cent. The remainder was recovered in the unsaponifiable fraction of fecal lipids. About 50 per cent of the absorbed activity was recovered in the lymph lipids.In the lymph lipids about half of the radioactivity was associated with palmitic acid, indicating a splitting of the ether bond of the chimyl alcohol and subsequently oxidation of the cetyl alcohol moiety to palmitic acid in the mucosa cells. The palmitic acid was incorporated into the lymph triglycerides and phospholipids in the usual way.The other half of the activity in the lymph was present as chimyl alcohol about half of which was present as free chimyl alcohol. The remainder of the chimyl alcohol had been esterified during the absorption process and behaved chromatographically as a triglyceride that yielded chimyl alcohol after alkaline saponification.Chimyl alcohol is thus well absorbed but extensively metabolized already during the absorption process.
Mechanism of the Relaxing Effect of: Adrenaline on Bovine Coronary Vessels
Authors: MOHME‐LUNDHOLM ELLA 
Published: December 2008

Summary.The effect of adrenaline, noradrenaline and lactic acid was investigated on isolated coronary vessels from cow.All these substances had a relaxing effect, coincident with an increase in the lactic acid content of the smooth muscle. The respective effects produced by adrenaline and noradrenaline were of similar magnitude to those induced by addition of lactic acid.Cu++ions totally inhibited the relaxing and lactic‐acid‐producing effects of adrenaline and noradrenaline on coronary vessels. The former effect was also completely abolished by other glycolysis inhibiting substances such as monoiodoacetic acid, sodium fluoride, dl‐glyceraldehyde, sodium azide, sodium arsenate and Ca+. ions, as well as by an increase in the alkalinity of the nutrient solution.The effect of other spasmolytics, such as theophylline, was not inhibited by glycolysis inhibiting substances or alkalization of the nutrient solution.These results suggest that the relaxing effect of adrenaline and noradrenaline on isolated blood vessels is due to their ability to stimulate the lactic acid production in the muscle layer.
The Inhibitory Action of a Compound Obtained from Hip Seeds (HSC) on the Release of Histamine and the Disruption of Nast Cells Produced by Compound 48/80 and Extracts from Jellyfish (Cyanea Capillata) and Eelworm of Swine (Ascaris Lumbricoides)
Authors: HÖGBERG BERTIL , SÜDOW GÖRAN , THON INGA‐LISA , UVNÄS BORJE 
Published: December 2008

Summary.Hip seed extracts prepared by repeated precipitation with alcohol or trirhloracetic acid extraction and barium fractionation were observed to block:(1)The histamine liberation produced in perfused cat's paw by 48/80 and by extracts from jellyfish (Cyanea capillata) and the eelworm of swine (Ascaris lumbricoides).(2) The rupture of mast cells produced by the same three agents.
Increase in Noradrenaline Excretion Following Activation of the Vasomotor System during Tilting in Adrenalectomized Patients
Authors: von EULER U. S. , FRANKSSON C. 
Published: December 2008

Summary.The noradrenaline excretion figures in adrenalectomized patients were significantly increased during tilting head‐up + 750 as compared with the figures during recumbency, indicating that reflex activation of the vasomotor system causes an overflow of neurotransmitter into the circulating blood from where it can be partly recovered in the urine.
Histamine Degradation in Tissue Extracts from the Cat
Authors: LINDAHL KERSTIN M. , LINDELL S.‐E. , WESTLING H. , WHITE T. 
Published: December 2008

Summary.1. The degradation of added histamine by crude extracts of kidney and small intestinal mucosa from adult cats was studied by measuring the oxygen consumption manometrically and by observing the loss of biological activity.2. It was found that these extracts contained a histamine degradating enzyme with the characteristics of diamine oxidase.3. No conclusive evidence was found in these experiments for the action of a histamine inactivating enzyme other than diamine oxidase.
Effects of Certain Biologically Occurring Substances on the Isolated Intestine of Fish
Authors: Von EULER U. S. , ÖSTLUND E. 
Published: December 2008

Summary.5‐Hydroxytryptamine strongly stimulated intestinal motility in Pleuronectes and Labrus. It was less active in Anguilla, Lophius, Squalus and Raja, and had little or no action in Myxine.Acetylcholine stimulated the isolated intestine in all species tested, although this effect was small in Squalus.Histamine contracted the intestine in Pleuronectes, Labrus and Gadus but had either a small or no action in Lophius, Anguilla, Raja and Myzine.Noradrenaline had only 1/30–1/100 of the inhibitory action of adrenaline on the intestine of Anguilla and Lophius. and 1/30 of the stimulating action of adrenaline on the intestine of Squalus.Substance P stimulated the intestine of all species tested.
The Effect of Vagotomy on Gastric Motor Responses to Drugs in Dogs
Authors: MUREN A. 
Published: December 2008

Summary.In gastric fistula dogs the gastric motor responses to carbachol, mecholyl and adrenaline were recorded under nembutal anaesthesia in repeated experiments before and after transthoracic vagotomy. Observations were made up to 200 days after operation.The threshold doses of the drugs mentioned for motor responses were markedly lowered by vagotomy and the responses to graded doses showed a corresponding increase as compared with preoperative responses.Increased sensitivity was usually apparent within the first 24 hours after vagotomy and maximal values were in most cases attained within the first 20 days. Later on, a decline in supersensitivity was observed, but preoperative values were not reached within 200 days after vagotomy. With carbachol and mecholyl the decline was pronounced; with adrenaline it was very slight.Similar experiments were performed on conscious dogs, using carbachol and pilocarpine. The results for carbachol agreed closely with those obtained in experiments performed under nembutal. The threshold dose of pilocarpine was found to be considerably reduced after vagotomy.
The Incorporation of Labelled Phosphate into Different Compounds in the Rat Kidney. The Effect of Parathyroid Extract on an in vivo System.
Authors: DE VERDIER CARL‐HENRIC 
Published: December 2008

Summary.The incorporation of P32 into nucleotides, phosphoproteins and RNA from rat kidney has been investigated in normal and parathyroidectomized animals and the effect of parathyroid extract has been studied. The rats were killed 1.5 hours after the hormone injection and 1 hour after the parenteral administration of radioactive phosphate. The renal nucleotide pattern is characterized by a relatively high concentration of a substance which is most likely uridine diphosphate or a derivative of it. The parathyroid hormone seems to specially stimulate the incorporation of radiophosphate into this compound and into the phosphoproteins.
Effects of Compound 48/80 on Blood Pressure and Plasma Histamine Level of Normal Dogs and Dogs with Mastocytoma.1
Authors: LARSSON BENGT 
Published: December 2008

Summary.Six healthy dogs and ten dogs with mastocytoma were studied. Of the latter, seven were treated with compound 48/80 intravenously. The blood pressure, plasma histamine and/or histamine content of the tumour was studied, and the results discussed in relation to the pertinent literature.
Catheterization of the Renal Arteries in Dogs and Cats
Authors: LINDELL S. E. , OLIN T. 
Published: December 2008

Summary.A technique of catheterization of the renal arteries from a femoral artery in dogs and cats is described.The catheter did not influence the renal blood flow as measured on the venous side.The insertion of the catheter was not followed by any changes in the clearance of phenol red as measured for each kidney separately.We are greatly indebted to Miss Karen Nilsson for help with the photometry and to Mr. Olle Jönsson, who prepared the gold tubes.
Multielectrode Study of the Territory of a Motor Unit
Authors: BUCHTHAL FRITZ , GULD CHRISTIAN , ROSENFALCK POUL 
Published: December 2008

Summary.By means of multielectrodes containing twelve leads along a 25 mm distance (Fig. 1) the spread of action potentials from a motor unit was studied over a cross section of the brachial biceps in man. The territory of the motor unit could be determined from the analysis of a single cross section of the muscle, since its fibres pass uninterrupted from tendon to tendon.The mutual position of two multielectrodes inserted perpendicularly to each other into the muscle was determined with an accuracy of 0.2 mm by recording with one multielectrode subthreshold pulses sent through successive leads of the other multielectrode (Fig. 2).The action potentials of a motor unit spread over an approximately circular area as evidenced by experiments in which the two multielectrodes traversed the centre of the motor unit (Fig. 4) and other experiments in which one of the multielectrodes was situated at the periphery of the motor unit (Fig. 5).Potentials with spike components exceeding 50 μV were confined to an average area four to six mm in diameter (Fig. 6 A). These potentials had a protracted terminal component of low amplitude and if they were recorded outside the site of innervation an initial positive component as well. Outside the area in which spike potentials occurred the potentials had a low amplitude, a short duration and a negative sign (Figs. 3, 4, 5).On account of volume conduction the action potentials were picked up in a larger area than occupied by the fibres of the motor unit. By means of the relationship between spike amplitude and distance from the potential source (Fig. 1 C) the average territory of the motor unit was determined to be four to six mm (minimum two and maximum ten mm) (Fig. 6 B). This area allows space for the fibres of ten overlapping motor units.On the same lead of the multielectrode action potentials from maximally six different motor units were recorded. Their potentials were often similar in shape so that they could be identified only by their discharge frequency (Fig. 9). The muscle fibres of as many as three of the intermingling motor units overlapped entirely (Fig. 8). The temporal dispersion of the spikes recorded on the different leads of the multielectrode was identical for these overlapping motor units (Fig. 7).The results are discussed with respect to their bearing on the parameters of the motor unit potential: The action potential of the motor unit arises from the summation of temporally dispersed potentials originating from fibre groups at a mutual distance of 0.3 to 1 mm. The amplitude of the motor unit potential is largely determined by the distance of the recording electrode from the fibre group closest to the electrode. The shape of the potential derives from the way in which the action potentials of two to three of these fibre groups summate. The duration of the potential is determined by the temporal dispersion of the component potentials due to the spatial dispersion of the end plates in the innervation zone.
Influence of Added Dead Space on Pulmonary Ventilation.
Authors: BOUHUYS AREND , JÖNSSON RAGNAR , LUNDIN GUNNAR 
Published: December 2008

Summary.Hyperventilation due to extra dead space did not cause any significant improvement in ventilatory efficiency as measured in nitrogen wash‐out experiments during oxygen breathing. In the experiments with extra dead space a significant increase in degree of uniformity of ventilation could be demonstrated. The subject's dead space increased, and the over‐all efficiency remained constant. The efficiency‐improving effect of a better distribution and the efficiency‐deteriorating effect of a larger dead space probably cancelled out. The better distribution is most probably explained by the effect of mixing of gas from different lung fractions in the large dead space. The experiments were performed with a nitrogen meter.
Carbon Monoxide Uptake in Man During Rest and Work.
Authors: BOSÆUS ELISABETH , FRIBERG LARS 
Published: December 2008

Summary.Ten resting subjects (5 nonsmokers and 5 smokers) were exposed to 0.010, 0.023, 0.040 and 0.080 vol. per cent CO. The work studies were made on 5 nonsmokers. They breathed 0.023 and 0.040 vol. per cent CO at rest and during work (bicycle ergometer) corresponding to 300, 600 and 900 kgm per minute.
Influence of the Vagal Innervation on Gastric Motor Responses to Adrenaline and Noradrenaline.
Authors: MUREN A. 
Published: December 2008

Summary.A large number of serial experiments on dogs have shown that the inhibitory effect of adrenaline and noradrenaline on gastric motility observed in conscious dogs is reversed to an augmentory one by different procedures which interfere with the normal vagal influence such as anaesthesia, vagotomy and treatment with atropine‐like substances.Acute experiments have shown that the augmentory responses obtained during anaesthesia are reversed to inhibitory ones when gastric motor activity is elicited by stimulation of the vagus in the neck. On the other hand, if gastric motor activity is induced by carbachol, the augmentory responses are not regularly reversed.The investigation was supported by a grant from the Medical Faculty in Lund.Technical assistance was given by Miss Asta Hector.
Studies on the Placental Transfer of Phosphate in the Guinea Pig:III. Phosphorus Compounds in the Placenta and their Uptake of Radioactive Phosphorus.1
Authors: FUCHS FRITZ , FUCHS ANNA‐RIITTA 
Published: December 2008

Summary.Determinations of the various phosphorus fractious in the guinea pig placenta in a series of experiments on the placental transfer of phosphate have shown that the orthophosphate concentration is very high in the placental tissue as compared with the maternal and foetal plasma. The concentration increases slowly from the 29th to the 59th day of gestation and may decrease thereafter.Thirty minutes after intravenous injection of radioactive phosphate into the mother the orthophosphate in the placenta has reached a specific activity of one third of that of the inorganic phosphate in the maternal plasma. It has the highest specific activity of the placental phosphorus fractions.Adenosine diphosphate and triphosphate are found in approximately the same concentrations as in the uterine muscle during pregnancy in the rat, the rabbit and the human. The labile phosphorus of these compounds is in equilibrium with the orthophosphate with regard to radioactive phosphorus.Glucose‐1‐phosphate is present in a low concentration, but it acquires a high relative specific activity. More glucose‐6‐phosphate is present, but with a low relative specific activity.The inorganic phosphate in the foetal plasma obtains in thirty minutes a specific activity of about half that of the placental orthophosphate.
Action Potentials Recorded Intra‐ and Extra‐ cellularly from the Isolated Frog Muscle Fibre in Ringer's Solution and in Air
Authors: HÅKANSSON C. H. 
Published: December 2008

Summary.Action potentials were recorded inside and outside isolated frog muscle fibres in Ringer's solution and in moist air in order to correlate the different potentials and to study volume conductionThe extracellular action potential recorded from isolated frog muscle fibres in Ringer's solution was diphasic with a first positive and a second negative phase.The duration of the potential measured at a distance of 30 μ from the surface of the fibre was 2.67 ± 0.14 msec (21.2° C). It increased slightly with increasing fibre circumference from 2.5 msec in a fibre of 150 μ circumference to 3.2 msec in a fibre of 350 μ, circumference.The amplitude increased proportionally to the square of the fibre circumference. The peak to peak amplitude was 0.8 to 2.9 m V 30 μ from the surface of the fibre. Near the fibre the amplitude decreased linearly with the logarithm of the distance from the axis of the fibre. At distances (d) exceeding 0.15 mm from the axis of the fibre the amplitude decreased as d‐1,3.The peak of the intracellularly measured potential coincided with the negative peak of the extracellular potential with the fibre in Ringer's solution. This indicates that the extracellular action potential can be accounted for by means of the second derivative of the intracellular potential. A third positive phase of the volume conducted potential which is present in nerve disappears within the noise level for the muscle fibre in Ringer's solution because of the more protracted course of repolarization.The spread of the action potential along the fibre determined from the intracellularly recorded action potential was 8.8 ±0.9 mm (conduction velocity × duration of the potential from 50 per cent rise to 50 per cent fall).From the action potentials recorded at different distances from the fibre equipotential lines of the travelling potential field were constructed. By means of this field the charge passing the membrane during depolarization was determined to 1.4× 10‐6 coulomb per cm2.The surface action potential from a fibre surrounded by a moist gas mixture had an amplitude of the same order of magnitude as the intracellularly measured action potential with the fibre surrounded by Ringer's solution. The time for rise from 20 to 100 per cent of crest was about half the rise time of the intracellularly recorded potential. The duration of the reconstructed monophasic potential from 50 per cent rise to 50 per cent full was slightly shorter than the intracellular action potential.The conduction velocity of the potential with the fibre in air was half that measured in Ringer's solution (2.41 ± 0.12 m per sec in Ringer's solution; 1.05 ± 0.05 m per sec in air at 21° C). From this difference in propagation velocity the impedance of the Ringer's film surrounding the fibre in air was estimated to 12 megohms per cm. The thickness of the Ringer's layer was about two μ.