bluuebunny/crossref_metadata_2025_split huggingface dataset:
Interindividual Differences in Diurnal Variations in Alertness, Performance, and Adrenaline Excretion
Authors: Pátkai Paula 
Published: December 2008

AbstractPátkai, P. Interindividual differences in diurnal variations in alertness, performance, and adrenaline excretion. Acta physiol. scand. 1971. 81. 35–46.Subjects classified as habitual morning vs. evening workers on the basis of their answers to a questionnaire, were compared with regard to day‐time variations in catecholamine excretion and performance. Adrenaline excretion in morning workers was highest in the morning and decreased gradually during the day, while evening workers showed nearly constant excretion values. The performance of morning workers did not vary during the day, while evening workers showed a steady improvement, performing best in the evening. In addition, a significant difference between the two groups was found in the personality dimension of extraversion‐introversion, showing that evening workers were more extravert and morning workers more introvert. The constancy of individual diurnal rhythms and their relations to personality traits, are discussed.
Cerebellar Suppression of the Autonomic Components of the Defence Reaction
Authors: Lisander Bjorn , Martner Jan 
Published: December 2008

AbstractLisander, B. and J. Martner, Cerebellar suppression of the autonomic components of the defence reaction. Acta physiol. scand. 1971. 81. 84–95.Experiments were performed on anesthetized‐curarized cats, where both the hypothalamic defence area and the cortex of the anterior cerebellar lobe could be stimulated while blood pressure, heart rate and muscle blood flow were recorded. Cerebellar stimulation which, when performed alone, had only insignificant cardiovascular effects, considerably reduced the increases in heart rate, blood pressure and muscle blood flow elicited by standardized defence area stimulations. The cerebellar suppression of the muscle vasodilatation appeared to be due to an interference with the cholinergic vasodilator fibre activation as elicited from the defence area. Thus, after complete pharmacological blockade of all adrenergic effects on the cardiovascular system, defence area stimulation still caused a marked, atropine‐sensitive muscle vasodilatation but this dilatation could be reduced by comcomitant cerebellar stimulation. In contrast, even strong activations of the baroreceptors did not interfere with the vasodilator fibre discharge as elicited from the defence area.Therefore, while the inhibitory baroreceptor reflex and the defence reaction because of their differentiated interaction act in synergism from the hemodynamic point of view (see Kylstra and Lisander 1970) the cortex of the anterior cerebellar lobe tends to suppress the defence reaction by exerting an inhibitory influence on essentially all the autonomic components of this response pattern.
Heparin‐Induced Increase of Diamine Oxidase in Lymph and Blood Plasma of Rat, Guinea‐pig and Rabbit
Authors: Hansson Roy , Thysell Hans 
Published: December 2008

AbstractAfter i.v. injection of heparin (1.6 IU/g b.w.) there was a significant increase of the diamine oxidase (DAO) activity in lymph and blood plasma in rat, guinea‐pig and rabbit. The ratio between lymph and plasma DAO activity was higher in rat and rabbit than in guinea‐pig under basal conditions. This difference was even more pronounced after heparin injection. Withdrawal of mesenteric or thoracic duct lymph from the circulation of the animals was accompanied by a poor response to heparin of the plasma DAO activity in rat and rabbit, whereas the response in the guinea‐pig seemed to be uninfluenced. These results suggest that, in analogy with earlier findings in man, the contribution from lymph to the heparin‐induced DAO response in blood plasma may be significant in the rat and rabbit, but not in the guinea‐pig.
Changes in the Electrochemical Potential Difference for HCO3‐‐ between Blood and Cerebrospinal Fluid and in Cerebrospinal Fluid Lactate Concentration during Isocarbic Hypoxia1
Authors: Mines A. H. , Sørensen S. C. 
Published: December 2008

AbstractThe changes in csf [HCO3‐] and [lactate] were followed in dogs whose arterial pH, Pco2, and [HCO3‐‐] were kept constant during 6 hrs hypoxia or normoxia. The results confirm that hypoxia causes a lowering of [HCO3‐]csf. We believe it is reasonable to assume that an increased anaerobic glycolysis in the brain is responsible for titrating HCO3‐‐ out of csf during isocarbic hypoxia although the lactate concentration in csf increased only about one third as much as the [HCO3‐‐] decreased. The action of hypoxia on [HCO3‐] esf is expressed in terms of its effect on the electrochemical potential difference for HCO3‐‐ between mean capillary plasma water and csf.
The Relative Contributions of Sodium and Chloride Ions to the Conductance of Toad Skin in Relation to Shedding of the Stratum Corneum
Authors: Larsen Erik Hviid 
Published: December 2008

AbstractBy means of short‐circuit and tracer technique, sodium transport, chloride transport, and D. C. conductance have been studied in toad skin in relation to moulting. It is shown that the skin loses its permselectivity, and that active sodium conductance increases as desquamation takes place. Subsequently the passive sodium permeability is lowered relative to the chloride permeability. The results are compatible with the hypothesis (Ussing and Windhager 1964), that the amphibian skin suppresses loss of ions along the extracellular pathway by means of tight junctions confined to the surface cells of the epithelium. It is confirmed that a rate limitation of the active sodium transport is located in the outermost part of the skin.
On the Innervation of the Slowly Adapting Stretch Receptor of the Crayfish‘ Abdomen. An Electrophysiological Approach
Authors: Jansen J. K. S. , Njå A. , Ormstad K. , Walloe L. 
Published: December 2008

AbstractThe synaptic effects of efferent fibres innervating the slowly adapting stretch receptor have been determined by intracellular records from reflexly intact receptors. Three such efferent fibres have been functionally identified. They all have an inhibitory action on the receptor and they probably correspond to the three efferent fibres described anatomically by Alexandrowicz (1967). The three types of IPSPs have similar reversal potentials and it is suggested that their synapses are intermingled and distributed over the somadendritic complex of the receptor. The inhibitory efficiency of the three types of IPSPs are markedly different, that of the thick accessory fibre being about five times more effective than the other two.
Metabolism of 14C‐Histamine in Domestic Animals
Authors: Eliassen K. A. 
Published: December 2008

AbstractThe metabolism of 14C‐histamine injected i.v. in 3 ruminant species (goat, sheep, and cow) has been studied previously. In the present study isotope dilution‐ and paper chromatographic techniques were used to examine urinary 14C‐metabolites of i.v. injected 14C‐histamine in the horse and the pig. The urine excreted the first 24 hrs after injection accounted for 64–76 % and 81–91 % of the radioactivity injected in horses and pigs, respectively. Less than 2 % of the injected radioactivity could be accounted for in the feces excreted the first week after injection. Known metabolites in the first 24 hr urine on an average accounted for about 94 % and 103 % of the urinary radioactivity in horses and pigs, respectively. Methylation of his‐tamine to 1.4‐methylhistamine and further oxidation to 1.4‐methylimidazoleacetic acid was quantitatively the most important pathway for histamine degradation, accounting on an average for about 63 % and 76 % of the radioactivity in horse and pig urine, respectively. The horse and the pig seemed to metabolize histamine in quite a similar way which again was quite different from that previously found in the ruminants in which oxidative deamination of histamine to imidazoleacetic acid was the only pathway of quantitative importance. As in ruminants histaminol seemed to be a metabolite of i.v. injected histamine accounting for about 2 % of the urinary radioactivity. The specific radioactivity of histamine was about tenfold larger than for 1.4‐methylmidazoleacetic acid, in horses and pigs.
Intravascular Concentrations of Calcium and Magnesium Ions and Edema Formation in Isolated Lungs
Authors: Nicolaysen Gunnar 
Published: December 2008

AbstractThe perfusate concentration of Ca++ has been assumed to be important for the permeability of the exchange vessels to proteins; low [Ca++] is said to result in edema development. The possible role of perfusate [Mg++] in this connection has previously not been considered. In the present work the correlation between the perfusate concentrations of Ca++ and Mg++ and edema development has been analyzed.In a perfused rabbit lung preparation edema developed at physiological intravascular pressures when the perfusate (plasma) [Ca++] was reduced to about 7. 10‐5 mM and the [Mg++] to about 1. 10‐3 mM by EDTA additions. Edema development was not seen at intravascular concentrations of Ca++ and Mg++ of about 4. 10‐5 and 4. 10‐1 mM, respectively. Such concentrations were achieved by addition of EGTA to the perfusate. Thus either the [Mg++] or the [Ca++] plus [Me++] in the perfusate must be the important parameter for the edema development. The changes in the capillary permeability induced by EDTA‐additions were largely reversible by addition of Ca++. This effect of Ca++ had a latency period of less than one min.
The Effect of Sympathetic Nerve Stimulation on Pulmonary Blood Volume in Isolated Perfused Lungs
Authors: Aarseth P. , Nicolaysen G. , Waaler B. A. 
Published: December 2008

AbstractAarseth, P. G. Nicolaysen, and B. A. Waaler, The effect of sympathetic nerve stimulation on pulmonary blood volume in isolated perfused lungs. Acta physiol. scand. 1971. 81. 448–454.Stimulations of the vago‐sympathetic nerve trunk at 5–10 imp/sec have been carried out in isolated dog lung preparations perfused at constant volume inflow. When the left atrial pressure was kept at 3–4 cm of water, the predominant response to these stimulations was a weight reduction of the preparation. This response is interpreted as being due to a reduction in pulmonary blood volume. Nerve stimulations caused only small weight reductions, or even weight augmentations, when the left atrial pressure was at or near zero. The blood volume reductions resulting from nerve stimulations appeared to be mediated via sympathetic nerve fibres and an α‐receptor mechanism.
Loci of Neurogenic and Metabolic Effects on Precapillary Vessels of Skeletal Muscle
Authors: Folkow Bjorn , Sonnenschein Ralph R. , Wright David L. 
Published: December 2008

AbstractFolkow, B., R. R. Sonnenschein, and D. L. Wright, Loci of neurogenic and metabolic effects on precapillary vessels of skeletal muscle. Acta physiol. scand. 1971. 81. 459–471.By cannulation of a branch of the proximally clamped sural artery of the anesthetized cat, distal arterial pressure (DAP) in the gastrocnemius muscle was recorded. Measurement of blood flow, femoral arterial pressure and DAP allowed calculation of total resistance (Rt) and its partition into a distal component (Rd) which included precapillary sphincters and the smaller arterioles, and a proximal component (RP) which included the larger arteries. With sympathetic vasoconstriction, the initial increase in Rt was accounted for mainly by constriction of the distal vessels which then tended to relax; progressive constriction of proximal vessels accounted for most of the elevated Rt during the steady state; subsequent reactive hyperemia mainly involved distal vessels. Rt was less affected by sympathetic stimulation during exercise than when the muscle was at rest; constriction of distal vessels was more markedly reduced than that of proximal vessels. Ascending dilatation was evident during exercise. Sympathetic cholinergic vasodilatation mainly involved vessels more proximal to those which were dilated early in exercise. The findings are compatible with the concept that capillary flow distribution, as a function of terminal arterioles and precapillary sphincters, is adjusted by local factors towards an optimum for the prevailing metabolic level of the tissue.
Electrophysiological and Morphological Development of Leg and Neck Muscles in the Rat
Authors: Boëthius Jörgen 
Published: December 2008

AbstractBoëthius, J. Electrophysiological and morphological development of leg and neck muscles in the rat. Acta physiol. scand. 1971. 81. 492–507.Membrane potentials were measured in the neck, sartorius and gastrocnemius muscles of postnatal rats. The potential rose from a constant value of 60–70 mV up to adult values of 80–90 mV. This increase, taking about 5 days, was earliest in the neck and latest in the gastrocnemius muscle. In the electromyograms of newborn rats the voltage of the motor unit potentials was higher and the duration shorter in the neck than in the gastrocnemius muscle. Mono‐phasic motor unit potentials were more common in the gastrocnemius than in the neck muscle. Later, the gastrocnemius potentials became comparable to those of the neck musculature. In the neck musculature, myotubes (3–27 %) were only found during the first day. In the sartorius and gastrocnemius muscles about 20 9% of the muscle cells were myotubes at birth. In each muscle the myotube‐myocyte transformation was completed on the day when the rise in membrane potential started. The correlation between the development of the membrane potential and the myotube‐myocyte transformation was also investigated in muecles denervated at birth and subsequently reinnervated. In such muscles the percentage of myotubes was 20–27 % at a time when the membrane potentials were of adult magnitude.
The Effect of Deep Halothane Hypotension upon Labile Phosphates and upon Extra‐ and Intracellular Lactate and Pyruvate Concentrations in the Rat Brain
Authors: Nilsson Lorentz , Siesjö Bo K. 
Published: December 2008

AbstractNilsson, L. and B. K. Siesjö, The effect of deep halothane hypotension upon labile phosphates and upon extra‐ and intracellular lactate and pyruvate concentrations in the rat brain. Acta physiol. scand. 1971. 81. 508–516.A study was made of the energy metabolism of the rat brain during deliberate hypotension induced by 2 % halothane and partial airway obstruction. A reduction of the mean arterial blood pressure to 30 mm Hg led to moderate increases in the extra‐ and intracellular lactate and pyruvate concentrations and in the lactate/pyruvate ratios, and to moderate decreases in the phosphocreatine content. At the same blood pressure level, hyperventilation with reduction of the PaCO2 to about 20 mm Hg aggravated the metabolic changes, indicating a further reduction of the cerebral blood flow. Although hypercapnia with an increase in tile PaCO2 to about 85 mm Hg decreased the tissue lactate content markedly, the oxidative metabolism was not normalized.It is concluded that although halothane hypotension with a reduction of the mean arterial blood pressure to about 30 mm Hg leads to changes in the energy metabolism of the brain, the changes are so moderate that a critical degree of hypoxia probably can be excluded. This conclusion may be even more valid if the mean blood pressure is not allowed to fall to such low values, and if marked hyperventilation is avoided at very low blood pressures.
Action Potential Generation in Denervated Rat Skeletal Muscle
Authors: Redfern Paul , Thesleff Stephen 
Published: December 2008

AbstractRedfern, P. and S. Thesleff, Action potential generation in denervated rat skeletal muscle. I. Quantitative aspects. Acta physiol. scand. 1971. 81. 557–564.Action potential generation was studied at various periods up to one week after denervation in individual muscle fibres of the extensor digitorum longus muscles of the adult rat. To allow a comparison of action potential generation at various stages of denervation, it was necessary to establish adequate conditions for spike generation. It was found that when fibres were locally polarized to a level of ‐90 to ‐100 mV, and the external calcium concentrations was increased to 4 mM, the peak rate of rise and the overshoot of the action potential were maximal. Between 30 and 40 hrs following section of the motor nerve, the mean maximal rate of rise of action potentials, recorded under the aforementioned conditions, was reduced by about one third, and remained at about this reduced level during the subsequent days. Two days after denervation the resting membrane potential was reduced from a mean of 82 mV in innervated muscle to a mean of 68 mV, and remained at about this level for the remaining 5 days studied. The electrical time constant and the input resistance of the muscle fibres gradually increased during the 7 days following denervation, the time constant by about 70 % and the input resistance by about 50 %. With anodal polarization in denervated muscle no significant correlation was found between the resting membrane potential and the maximal peak rate of rise of the spike. It was concluded that denervation produces a genuine reduction in the rate of rise of the action potential in muscle fibre.
The Effect of Cordycepin on Nuclear RNA Synthesis in Nerve and Glial Cells
Authors: Grahn B. , Lovtrup‐Rein H. 
Published: December 2008

AbstractThe effect of cordycepin on RNA synthesis in isolated nuclei of neurones, astrocytes, and oligodendro‐ and microglial cells, is reported. This drug selectively inhibits the formation of ribosomal RNA and its precursors. Two independent components, with sedimentation coefficients of 25S and 12S, and high rate of turnover, remain however unaffected. They are shown to be non‐ribosomal RNAs and are assumed to be of messenger type. The effect of cordycepin is the same on all three types of nuclei studied.
Release of Histamine and Formation of Slow Reacting Substance in the Cat Paw Induced by Compound 48/80
Authors: Strandberg Kjell 
Published: December 2008

AbstractA method for perfusion of cat paws with constant flow and temperature is described. This technique has been used to study the relationship between the efflux of histamine and slow reacting substance (SRS) from cat paws perfused with compound 48/80. The threshold dose of compound 48/80 was 0.001–0.01 μg/ml for both histamine and SRS releasing effects. No correlation between the yields of histamine and SRS was noted. On repeated administration of compound 48/80 the histamine releasing effect declined and the output of SRS was cor respondingly reduced. The release of histamine and the formation of SRS were inhibited by ninhydrin, N‐ethylmaleimide and potassium cyanide indicating that both processes are dependent on energy‐requiring enzymatic reactions. Apart from their antagonism of the histamine releasing effect of compound 48/80, ninhydrin and N‐ethylmaleimide released histamine per se. No SRS was detected in the effluents from paws perfused with these agents alone. The yields of both histamine and SRS were higher at 22o C than at 37oC. Regardless of temperature the efflux of histamine consistently preceded that of SRS. A temperature dependent inactivation of SRS by cat serum was demonstrated. The results suggest that the initial reaction(s) activated by compound 48/80 is common for the release of histamine and the formation of SRS in the cat paw but that these processes then proceed independently.
Rapid Interaction between Gonadotrophic Hormones and the Prepubertal Rat Ovary
Authors: Ahrén Kurt , Hamberger Lars , Perklev Torsten 
Published: December 2008

AbstractLactic acid production by isolated ovaries from prepubertal rats was used as an experimental system to characterize the initial interaction between luteinizing hormone (LH) and human chorionic gonadotrophin (HCG) on the one hand and the ovarian tissue on the other hand. Injection of bovine LH, 30, 5 and 1 min, respectively, before extirpation of the ovaries from the rats, produced a marked increase in lactic acid production by the isolated ovaries during a following 2 hr incubation period. The effect was very pronounced already in ovaries from rats injected with LH for only 1 min before removal of the ovaries, but the effect was slightly more pronounced in the “5 rnin group”. There was, however, no significant difference between the “5 min group” and the “30 min group”. There were also persistent effects of both LH and HCG after 1–5 rnin exposure of the ovaries to the hormone in vitro followed by careful wash in hormone‐free medium. These effects did not become more pronounced when the hormone was also present during the entire 2 hr incubation period when lactic acid production was measured. The same rapid interaction between hormone and ovary was seen at both +37° C and +l ° C. Addition of an anti‐HCG serum before or together with HCG completely prevented the effect of the hormone. When the ovaries were first exposed to HCG for 1 min and then to anti‐HCG serum for 1–5 min, the anti‐serum did not abolish the hormone effect. There was no cross‐reaction between anti‐HCG serum and bovine LH. The results are discussed in relation to similar experiments with other polypeptide hormones, and in relation to various theories of the initial interaction between the hormone and the target cell.
Thrombocytes and Pulmonary Vascular Resistance during Hemorrhagic Hypotension
Authors: Bø G. , Hognestad J. 
Published: December 2008

AbstractProlonged hemorrhagic hypotension can induce an increase in pulmonary vascular resistance (PVR). In anesthetized cats with open chests and with positive pressure ventilation aortic blood flow, pulmonary arterial‐, left atrial‐ and femoral arterial pressures were recorded. Eight animals were bled until the mean arterial pressure was 50 nun Hg and this level was main tained for 3 hrs by further bleeding and/or small retransfusions. The animals were then retransfused. Another group of 5 animals were made thrombocytopenic by shunting their blood through a column of glassbeads. These animals were then bled in the same way and kept hypotensive for the same period of time.During hypotension PVR in the first group increased gradually and by 370 per cent (mean value). In the thrombocytopenic group PVR increased only by 125 per cent (mean value) (P<0.01). The number of thrombocytes in arterial blood in the former group of animals decreased gradually by 37 per cent during the hypotensive period. Only in 2 of the 8 animals in this group did examination with light microscopy reveal scattered thrombocyte aggregates in small pulmonary vessels.The thrombocytes thus seem to be involved in the development of increased PVR during hemorrhagic hypotension. The fact that intravascular thrombocyte aggregates were not general ly found may indicate that the thrombocytes act by other mechanisms than by simple vascular obstruction alone.
Biological Evaluation of Protein Quality and Safety of a Lipoprotein Concentrate from Niger Seed* (Guizotia Abyssinica Cass.)
Authors: Eklund Anders 
Published: December 2008

AbstractGrowing rats were fed diets containing a lipoprotein concentrate prepared from niger seeds, as the sole source of protein. Protein efficiency ratio (PER) and productive protein value (PPV) were calculated for two levels of protein in the diet, 11.1 % and 22.4 %, respectively. When the protein content of the diet was 11.1 % the PER was 2.37 (for a feeding period of three weeks). The corresponding PPV was 42.0. A short term toxicological feeding study was carried out on rats fed with these diets for a 90‐day period. No significant diet‐related changes were observed in the growth, appearance, behaviour and survivals of the animals. Hematological findings were normal. The histopathological examinations of the main organs gave normal results. Electron microscopy showed an increased amount of multi‐vesicular bodies (possibly lysosomes) as well as an increased content of fat droplets in the cytoplasm of liver cells. The significance of these changes remains unclear.