bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Study of Thirst and Other Effects of an Increased Sodium Concentration in the 3rd Brain Ventricle
Authors: Anderson B. , Jobin M. , Olsson K. 
Published: December 2008

ABSTRACTThe characteristics of thirst elicited by injections of hypertonic NaC1‐solution into the 3rd brain ventricle were studied in goats supplied with permanent ventricular canola. Animals in normal water balance drank 1.5 to 2.0 1 of water within 2 min after the intraventricular injection of 0.1 ml of 0.85 M NaC1. In the hydrated animal this thirst response was markedly diminished or completely absent. If the goats were not allowed to quench their thirst immediately after the intraventricular injection of hypertonic NaC1, the urge to drink gradually became weaker and disappeared after about 20 min. Single or repetitive injections of 0.1 ml of 0.85 M NaCl into the 3rd brain ventricle were further found to cause a conspicuous increasz in urinary excretion of Na+ and C1– and to inhibit temporarily an established water diuresis. Aldosterone treatment did not prevent the increase in urinary electrolyte excretion occurrinz after injections of hypertonic NaCl into the 3rd ventricle.Repetitive injections of 0.1 ml of 0.85 M NH4Cl or of 1.7 M d‐glucose into the 3rd ventricle, or injections of 0.1 ml of 0.85 M NaCl into the lateral ventricle did not induce drinking or cause any increase in urinary electrolyte excretion.
Application of High‐Frequency Reflectometry for Measurement of Minute Changes in Electrolytic Conductance
Authors: Haapanen L. 
Published: December 2008

ABSTRACTThe paper presents a method of measuring small variations in electrolytic conductance applicable also to dynamic measurements. By means of a probe immersed in the solution a high‐frequency field is applied, variations in the absorption of which are detected by a special instrument, the H‐F reflectometer, and indicated on separate meters as changes in resistive and capacitive components of the combined impedance, of probe and electrolyte. At the frequency used, 1085 kc/s, absorption maximum occurs at conductivities around 10–4 ohm‐1 cm‐1, at which a change in conductivity of 10‐1 ohm‐1 cm‐1 can be measured with reasonable accuracy in long‐term experiments and transient changes of 10–8 ohm‐1 cm‐1 can be detected using variations in the capacitive component as index. By means of a graphical method an analysis is made of an equivalent circuit simulating the electrical properties of an electrolyte. It is shown that a series circuit of a varying resistance and a fixed‐value capacitance approximates several of the characteristics of a solution.
Recording of the Ionic Efflux during Single Action Potentials in Nitellopsis Obtusa by Means of High‐Frequency Reflectometry
Authors: Haapanen L. , Skoglund C. R. 
Published: December 2008

ABSTRACTThe ionic efflux during a single action potential of the alga Nitellopsis obtusa was recorded by measuring the increase in conductivity of the extracellular fluid. The conductivity changes are reflected as variations in absorption of a high‐frequency field applied by a specially designed probe placed in the external medium close to the alga and connected to a high‐frequency reflectometer. The combined characteristics of probe/solution and reflectometer are given. Most experiments were performed on algae in distilled water, comparative experiments with lake water having shown that this arrangement does not introduce any significant changes in the activation processes studied. The possibility of dynamic recording of ionic fluxes is illustrated by oscillograph records showing the temporal relation between the ionic concentration change and the action potential; that the method is suitable for quantitative measurements is demonstrated by inkwriter records showing the stepwise increases in concentration caused by intermittent stimulation during hour‐long experiments. Quantitative data on the increments in ionic concentration associated with a single impulse, and on the total increase resulting from a number of stimuli, are presented and compared with chemical analyses showing the ions involved to be K+ and C1‐‐. Satisfactory correspondence was obtained between the values of the conductivity measurements, tentatively expressed as KC1 concentration, and the chemical analysis. The average values for the K+ efflux were 2 times 103 to 4 times 103 pmole/cm2. impulse; preliminary studies showed the C1– efflux to be of approximately the same order.
Effects of Adrenaline on Coronary Flow in Isolated Perfused Rat Hearts
Authors: Glomstein Anders , Hauge Anton , ØYe Ivar , Sinclair Derek 
Published: December 2008

ABSTRACTThe mechanism for adrenergic regulation of coronary flow has been studied in an isolated, working rat heart preparation. It is concluded that adrenaline affects coronary flow in this preparation through three separate modes of action: 1. Constriction of the coronary resistance vessels mediated through a‐type of adrenergic receptos in these vessels. 2. Dilatation of the coronary resistance vessels mediated through β‐type of adrenergic receptors in these vessels. J. Dilatation of the coronary resistance vessels as a consequence of increased myocardial metabolism after adrenaline.
Studies of the Importance of the Thyroid and the Sympathetic System in the Defence to Cold of the Goat
Authors: Anderson B. , Ekman L. , Hökfelt B. , Jobin M. , Olson K. , Robertshaw D. 
Published: December 2008

ABSTRACTMarkedly hypothyroid goats were found to retain the ability to maintain body temperature during acute cold exposure (‐ 3° C), and to react to local cooling of the hypothalamic thermoregulatory “centre” by a rise in body temperature. However, the shivering response to external cold and to hypothalamic cooling was strongly accentuated, and the increase in urinary excretion of cate‐cholamines (especially of adrenaline) was generally much greater than that of the euthyroid goat. In 3 out of 4 hypothyroid goats studied, the catecholamine excretion at room temperature was also higher than that found in euthyroid goats. During acute cold exposures the blood glucose of the hypothyroid goats rose by about 300 per cent as compared to a rise of about 20 per cent in the euthyroid animals. It is concluded that to maintain thermal homeostasis in the cold markedly hypothyroid goats have to compensate the lack of thyroid hormone by a conspicuous increase in adrenaline secretion. Bilateral splanchnicotomy in the euthyroid goat resulted in practically complete absence of adrenaline in the urine, but did not present the rise in body temperature and the shivering seen during local cooling of the anterior hypothalamus. However, the hyper‐glycemic response to hypothalamic cooling was blocked completely.
The Effect of H+— and Lactate Ions on the Electrical Activity and Content of High Energy Phosphate Compounds of Taenia Coli from the Guinea Pig
Authors: Aaberg Gunnar , Mohme‐Lundholm Ella , Vamos Nandor 
Published: December 2008

ABSTRACTReduction of the pH in Krebs solution with 0.05–0.4 units by adding lactic acid or acetic acid to a final concentration of 0.1–1.0 mmoles/l or by increasing the CO2 concentration from 3–12 % (pH change 0.28) in the gassing mixture caused relaxation of isolated taenia coli from the guinea pig. In determining the electrical activity of the membrane of the muscle by the “sucrose gap” method, it was found that a pH reduction inhibited the action potential, and with yet lower pH values hyperpolarization was observed. In K+‐depolarized muscle a similar pH reduction had a tension‐increasing effect. Na+‐lactate increased the electrical activity of the membrane and had a tension‐increasing effect. — The addition of lactic acid in a concentration of 1 mmole/l which relaxed the carbacholine stimulated muscle, had no effect on the content of high energy phosphate compounds. It seems probable that the relaxing effect of H+‐ions was a result of its inhibitory effect on the electrical activity of the membrane.
Choline Acetylase in Normal and Denervated Submaxillary Glands of Rats after Repeated Teeth Amputations
Authors: Ohlin Per , Perec Carlos Jose 
Published: December 2008

ABSTRACTThe size of the rat's submaxillary gland and the total activity of choline acetylase in the gland were markedly and similarly increased after repeated teeth amputations. Preganglionic parasympathet‐ic denervation caused an atrophy of the gland and a pronounced decrease in enzyme activity. It did not inhibit the effects of repeated teeth amputations. Postganglionic sympathetic denervation alone caused a slight decrease in gland weight and an increase in choline acetylase activity. The effect of repeated teeth amputations was partly inhibited in sympathetically denervated glands. It was completely abolished in both parasympathetically and sympathetically denervated glands.
Presence of Free and Conjugated Noradrenaline in Human Cerebrospinal Fluid
Authors: Dencker S. J. , Häggendal J. , Ilves‐Häggendal M. 
Published: December 2008

ABSTRACTThe noradrenaline (NA) in the lumbar cerebrospinal fluid (CSF) was estimated by the trihydroxy‐indole reaction in patients with lumbar root syndromes or with mental diseases. The mean values found were 0.2±0.08 pg/l (7 cases) and 0.5±0.03 μ g/l (68 of 72 cases), respectively. In 4 cases of the latter group much higher values were obtained. In one case adrenaline was found in the CSF. So significant amounts of dopamine were demonstrable in the CSF.Conjugated NA in the CSF, which was detected in 19 of 22 cases studied, increased after oral administration of NA. The origin of free and conjugated NA in CSF with respect to the blood‐SCF barrier is discussed.
Studies on the Transport and Life‐span of Amine Storage Granules in the Adrenergic Neuron System of the Rabbit Sciatic Nerve
Authors: Dahlström Annica , Haggendal Jan 
Published: December 2008

ABSTRACTThe accumulation of noradrenaline above a ligation of the albino rabbit sciatic nerve and the noradrenaline content of the adrenergic fibre system emanating from the sciatic nerve were determined biochemically. Using the obtained data the transport and life‐span of amine granules were calculated to be about 3 mm per hr and about 50 days, respectively.
Constancy of d(+)Xylose Space in Man during Brief Exercise
Authors: Hasan J. , Karvonen M. J. , Piironen P. , Ruosteenoja R. 
Published: December 2008

ABSTRACTMeasuring the concentration of xylose in blood at intervals between the 15th and 65th minute following a rapid i.v. injection of 12.5 g of d (+)xylose into 5 healthy males, we found it decreasing at a steadily diminishing rate, indistinguishable from that of a single exponential process with an average half‐period of about 60 min. Starting at 30 min after the injection, the subjects worked for 10 min on a bicycle ergometer at 18 kpm/sec. This activity did not alter significantly the linear time course of the logarithm of blood xylose concentration, either during the exercise or in the 25 min of observation following it. A rough evaluation of possible contributing factors shows that any increase in the apparent volume of distribution of xylose during or after the exercise cannot have exceeded approximately 12 per cent of its average initial value, which was about 21 per cent of the subjects' average body weight. Thus, observations on human subjects in physiological conditions failed to confirm the contention, derived from findings in electrically induced muscular contractions of anesthetized animals, that the permeability of the cell membrane to sugars is increased to a physiologically important extent during muscular exercise, the alteration allegedly resembling closely that brought about by insulin. We conclude that the discrepancy between the present findings and those reported previously may be due to an interspecies difference in mechanisms of regulation or, rather, it reflects the fact that previous experiments involved far from physiological conditions, likely to induce e.g. fluid shifts and consequent distortions of interpretation.
Suppression of Cortical Spontaneous Barbiturate Spindles via Specific and Unspecific Projection Spinal Pathways
Authors: Anderson Sven A. 
Published: December 2008

ABSTRACTThe effects of peripheral adequate stimulation on cortical barbiturate spindles were investigated after spinal lesions in lightly anesthetized cats. Certain effects can be evoked from the specific projection pathways, the dorsal columns and the spino‐cervical tract, but a generalized suppression of cortical spindles was obtained mainly via two other pathways. One of these pathways, identified as the bilateral ventral flexion reflex tract, ascends in the ventral funiculus. The other pathway ascends in the dorsolateral funiculus and consists of thin, possibly unmyelinated fibres. Both pathways could be activated by low and high threshold receptors in bilateral fields and gave a desyn‐chronization of cortical spindles outlasting the duration of stimulation. The cortical effects mediated via the specific projection spinal pathways were mainly found in somatosensory projection areas with a local abolition of spindles and increased background activity. In very light anesthesia a small and shortlasting generalized effect could sometimes be obtained.
Serum Proteins in the Hedgehog
Authors: Larsen Bodil , Tönder Olav 
Published: December 2008

AbstractHedgehog serum proteins were studied by physical, chemical and immunological methods. The paper electrophoretic and immunoelectrophoretic patterns did not differ greatly from those of human serum. In paper electrophoresis two beta‐bands were found, the beta2‐band being the most conspicuous. In the immunoelectrophoretic pattern, the form of the “rapid” lipoprotein‐line was found to vary with temperature and duration of storage of serum. Autoradiography showed transferrin in hedgehog serum to be a beta2‐globulin. Antibody activity was found in two different fractions after gel filtration or ultracentrifugation of serum, probably representing antibodies of the 19S and 7s types.
Glycogen Phosphorylase: A Specific Secondary Target System for Adrenergic Stimulation in the Heart
Authors: ØYE IVAR 
Published: December 2008

AbstractGlycogen phosphorylase (α‐1,4‐glucan:orthophosphate glucosyltransferase, EC 2.4.1.1.) was studied in the isolated rat heart in the asystolic and the working state. Increasing work loads did not affect the amount of phosphorylase α. Anoxia was found to increase the levels of phosphorylaseaL, but this effect could be completely prevented by pretreatment with adrenergic beta receptor blocking agents. These agents also lowered the levels of phosphorylaseain the heartin vivoto levels close to those found in the isolated, perfused heart. It is concluded that the phosphorylase transformation system in the rat heart under physiological conditions serves as a specific secondary target for adrenergic stimulation.
Response of Rat Atrium to Propranolol and Catecholamines in Various States of Thyroid Action
Authors: Hirvonen Leo , Paavilainen T. O. A. 
Published: December 2008

AbstractThe effect of propranolol on spontaneous beating, and the response of this to adrenaiinc and noradrenaline, was studied in hypothyroid, euthyroid and thyroxine treated isolated atrium of the rat hcart. A significant negative chronotropic effect was noted in thyroxinized preparations; in other groups this change was less significant. The inotropic property remained unchangcd in control conditions. A propranolol dose of 1 μg/ml blocked the positive chronotropic effect of adrenaline and noradrenaline completely in euthyroid and thyroxinized atria and partially in the hypothyroid ones. A competitive antagonism was observed between propranolol and catecholainines in the various preparations when contraction force and mechanical output werr measured. Thc positive inotropic effect of adrenaline and noradrenaline was highest in the hypothyroid and lowest in thr thyroxinized series. Only quantitative differences were ohserved in the responses of the atria to propranolol and catecholaminrs in various states of thyroid action.
Histamine Release from Rat Mast Cells Induced by a Mast Cell Degranulating Fraction in Bee Venom
Authors: Fredholm Bo , Haegermark ÖSten 
Published: December 2008

AbstractBee venom is known to contain high amounts of phosphatidase A and to cause degranulation and histamine release in rat mast cells. In the present study bee venom was fractionated on Sephadex G 50, whereby the phosphatidase A (Fraction F I) was separated from the histamine releasing activity (Fratcion F II). Various aspects of the F II‐induced histamine release from rat peritoneal mast cells were studied, namely the dose‐response curve, the time course of the reaction, the pH and temperature dependency, and the influence of inhibitors. It is concluded that this bee venom fraction acts by a mechanism similar to that of compound 48/80. This is in contrast to findings reported for melittin, a histamine releasing bee venom fraction described by other authors.
Circulatory and Respiratory Adaptation during Prolonged Exercise of Moderate Intensity in the Sitting Position
Authors: Ekelund L.‐G. 
Published: December 2008

AbstractCirculatory and respiratory adaptation during prolonged exercise of moderate intensity in the sitting position were studied with heart catheterization technique in 6 healthy young men of ordinary, physical fitness. The work load was chosen so that they worked at a level of 57.3 per cent of the rate of work they could perform at a pulse rate of 170 beats/min. This load gav a mean heart rate of 126.7 beats/min after 10 min and 138.5 beatslmin after 60 min of work. The circulatory changes under these experimental conditions were characterized by a constant cardiac output with a continuous increase in heart rate and a continuously falling stroke volume. The systemic arterial mean blood pressure fell slightly but significantly and the mean pulmonary arterial pressure also decreased significantly from 10 to 40 min work. The total blood volume decreased 7.2 per cent from rest to 10 min work and then remained unchanged. The respiratory response was characterized by a numerical increase (P<0.1) in total ventilation, dead space ventilation and an unchanged alveolar ventilation. The respiratory quotient increased from rest to the beginning of the exercise and then decreased significantly. The observed changes during prolonged exercise may be explained by a decreased vasomotor tone with a change in the compliance of the capacity vessels and the distribution of the blood volume. The relative level of work intensity seems to be more important than the body position to maintain a steady state.
A Mathematical Definition of the Tonicity of the Galvanic Skin Reaction in the Cat
Authors: Lang A. H. 
Published: December 2008

AbstractLittle attention has previously been paid to the time characteristics of the galvanic skin reaction (GSR). According to recent studies carried out in this laboratory, the intensity and time course of the GSR can be controlled differentially by the CNS. For analysing GSR dynamics quantitatively a reliable method of measuring its time characteristics is needed. The paper deals with this general problem of measurement. Based on empirical material it is suggested that the ratio of the area of the GSR curve, measured planimetrically, to the product of its peak amplitude and the recording speed, is a reliable index of the tonicity of most GSRs recorded under various experimental conditions. The tonicity or time index, designated as the TI of the GSR, has the dimension of time. It is expressed in seconds and its value is independent of the recording parameters used. Actually the TI is equal to the time for decay of the ‘integrated and averaged’ GSR curve to half its maximum amplitude. For detailed analysis the TIs of separate sections of the GSR can be determined in the same way as that for the total reaction. Examples from different experiments illustrating the need and the employment of the new method of analysis are given.
Blockade of the Calorigenic, Hyperglycemic, Lactic Acid‐producing and Fatty Acid‐mobilizing Effects of Adrenaline by an Adrenergic β‐receptor Blocking Agent (Pronethalol) in Experiments on the Rabbit
Authors: Svedmyr Nils 
Published: December 2008

AbstractPronethalol in a dose of 6 mg/kg greatly inhibited the stimulatory effect of adrenaline given in an intravenous infusion of 0.5 μ/kg/min for 60 min, on the oxygen consumption in the rabbit. Pronethalol also blocked the stimulatory action of adrenaline on the lactic acid production, and its hyperglycemic and fatty acid‐mobilizing effects. The relationship between these effects are discussed.
Muscle Glycogen during Prolonged Severe Exercise
Authors: Hermansen Lars , Hultman Eric , Saltin Bengt 
Published: December 2008

Abstract10 well trained and 10 untrained subjects worked to complete exhaustion on a bicycle ergometer with work loads averaging 77 (76–87) per cent of their individual maximal aerobic power. Determinations of glycogen used by working muscles (biopsy of lateral portion of the quadriceps femoris muscles) and of combusted carbohydrate (Vo2 and RQ) were performed at certain intervals from the start of work to exhaustion. At a combustion rate of about 3 g carbohydrate per minute (RQ around 0.9 or higher) and at average values for glycogen in resting muscle of 1.6 (1.1–2.5)g/100 wet muscle, the effective work time was around 85 min for the untrained and 90 min for the trained subjects. At the end of the exhaustive exercise the glycogen content averaged 0.06 g in the untrained and 0.12 g/100 g wet muscle in the trained subjects. A close relationship between utilized glycogen and combusted carbohydrate was found, and it seems highly probable that at high relative workloads primarily the glycogen stores in the exercising muscles will limit the capacity for prolonged strenuous work.
Diet, Muscle Glycogen and Physical Performance
Authors: Bergström Jonas , Hermansen Lars , Hultman Eric , Saltin Bengt 
Published: December 2008

AbstractThe muscle glycogen content of the quadriceps femoris muscle was determined in 9 healthy subjects with the aid of the needle biopsy technique. The glycogen content could be varied in the individual subjects by instituting different diets after exhaustion of the glycogen store by hard exercise. Thus, the glycogen content after a fat ± protein (P) and a carbohydrate‐rich (C) diet varied maximally from 0.6 g/100g muscle to 4.7 g. In all subjects, the glycogen content after the C diet was higher than the normal range for muscle glycogen, determined after the mixed (M) diet. After each diet period, the subjects worked on a bicycle ergometer at a work load corresponding to 75 per cent of their maximal O2uptake, to complete exhaustion. The average work time was 59, 126 and 189 min after diets P, M and C, and a good correlation was noted between work time and the initial muscle glycogen content. The total carbohydrate utilization during the work periods (54–798 g) was well correlated to the decrease in glycogen content. It is therefore concluded that the glycogen content of the working muscle is a determinant for the capacity to perform long‐term heavy exercise. Moreover, it has been shown that the glycogen content and, consequently, the long‐term work capacity can be appreciably varied by instituting different diets after glycogen depletion.
Studies on Morphological Changes and Histamine Release Induced by Bee Venom, n‐Decylamine and Hypotonic Solutions in Rat Peritoneal Mast Cells
Authors: Bloom Gunnar D. , Haegermark ÖSten 
Published: December 2008

AbstractHistamine release and concomitant morphological changes in rat peritoneal mast cells were studied under various conditions. It was found that mast cells react somewhat differently, depending on the means by which histamine release was brought about. Bee venom produced effects similar to those of compound 48/80 and seemed to trigger an active cell process with extrusion of mast granules as a final result. n‐Decylamine and hyposmotic solutions appeared to bring about histamine release by affecting the integrity of mast cell fine structure resulting in a breakdown of plasma membrane and cellular compartments.