bluuebunny/crossref_metadata_2025_split huggingface dataset:
Refractory Period and Conduction Velocity of the Striated Muscle Fibre*
Authors: Buchthal Fritz , Engbæk Lise 
Published: December 2008

AbstractBuchthal, F. and L. Engbæek, Refractory Period and conduclion velocity of the striated muscle fibre. Acta physiol. scand. 1963. 59. 199–220. —Refractory period and conduction velocity of transmembrane potentials were determined in single frog muscle fibres by intracellular stimulation and recording at 14, 20 and 25° C. At the end of the absolutely refractory period the latency of the potential evoked by the second stimulus was substantially increased mainly due to a reduction in conduction velocity, delayed firing causing at most 10 per cent of the total delay. The absolutely refractory period terminated at the onset of the negative after potential, recovery in excitability, amplitude and conduction velocity in the relatively refractory period occurred within a time interval in which the membrane potential did not change more than about 3 mV. At 2–3 times the absolutely refractory period excitability and conduction velocity had a supernormal phase. At the absolutely refractory period the level of depolarization required to initiate a propagated response had increased from 40 to more than 60 mV (recorded 0.25–0.6 mm from the stimulating electrode). A local response appeared at a time interval of 70–80 per cent of the absolutely refractory period of the propagated response.
The Presence of Conjugated Adrenaline and Noradrenaline in Human Blood Plasma
Authors: Häggendal Jan 
Published: December 2008

AbstractHäggendal, J. The presence of conjugated adrenaline and noradrenaline in human blood plasma. Acta physiol. scand. 1963. 59. 255–260. –The presence of conjugated adrenaline and noradrenaline in blood plasma is shown. As a rule 2 to 3 times more conjugated than free noradrenaline was found. When the free noradrenaline and adrenaline plasma levels were increased during muscular work and during insulin hypoglycemia, respectively, the levels of conjugated cate‐cholamines did not markedly change. After the oral administration of 5 mg adrenaline to a healthy man high amounts of conjugated adrenaline was found in the plasma and in the urine.
Handling of Glycerol in the Kidney
Authors: Kruhøffer Poul , Nissen Ole I. 
Published: December 2008

AbstractKruhøffer, P. and O. I. Nissen.Handling of glycerol in the kidney. Acta physiol. scand. 1963. 59. 284–294. —Essentially complete reabsorption of glycerol (and urine/plasma ratios below one) was observed in cats at low filtered loads. With increasing filtered loads the reabsorption rate continued to rise and the reabsorption fraction converged upon a value of about 0.4. The rate of metabolic conversion of glycerol in the kidneys – simultaneously determined from measurements of renal blood flow and arterio‐venous deficits –exceeded the reabsorption rate at low filtered loads whereas the relation was undoubtedly reversed at high filtered loads. Stop‐flow experiments indicated that the most distal parts of the nephron are sparsrly permeable to glycerol and that concentrations below that of arterial plasma may arise in proximal parts. The observations ma)‐ be accounted for on the assumptions that reabsorption at low filtered loads is predominantly a conversion reabsorption (diffusion from the tubular lumen into tubular cells maintained by a metabolic convcrsion inside the cytoplasm) and that at high filtered loads well above the level of saturation of the glycerol converting enzymes it is essentially due to transcellular back‐diffusion through the (proximal) tubular cells. I'he pattern of renal excretion of glycerol may thus be interpreted without resorting to special transmembranr transfer mechanisms.
Radiation Induced“Hypophysectomy” and Hypothalamic Lesions in Lactating Goats
Authors: Galel Charles C. , Larsson Wörje 
Published: December 2008

AbstractRadiolesions were produced in the pituitary gland and/or median eminence‐pituitary stalk region of seven lactating goats by use of a narrow, collimated beam of 185 MeV protons from a synchrocyclotron. Radiation doses of 25 to 30 krad were restricted to these structures by rotation of the goats' heads around the vertical and horizontal axes of the planned lesion. Ten to 15 days after pituitary irradiation in four goats, milk production declined steeply over a ten‐day period to about 20 per cent pre‐lesion levels. In two of the“hypo‐physectdmized” animals with injury also in the median eminence, diabetes insipidus developed concurrently with the onset of lactation block. Daily replacement with prolactin (luteotrophin), somatotro‐phin, ACTH, triiodothyronine, and insulin had restored milk synthesis to 60 per cent of pre‐radiation levels when destruction of trigeminal nerve trunks by continued lateral spread of radiolesions caused an abrupt decline in the health of the goats.In 3 lactating goats, irradiation of the median eminence/pituitary stalk region was followed after 25 to 30 days by (1) disappearance of the milk ejection reflex, (2) onset of diabetes insipidus characterized by absence of the normal interphase, (3) decline in milk production to 30 to 40 per cent of pre‐lesion levels, and (4) in one of them, marked loss of hair. That median eminence lesions blocked lactation secondary to pituitary insufficiency of ACTH, TSH, and STH, but not of prolactin or of oxytocin was suggested by the ability of varied therapeutic regimens to restore lactation.
Röntgenologische Bestimmung des Herzvolumens der Ratte
Authors: Tribukait Bernhard 
Published: December 2008

AbstractA method for X‐ray determination of the heart volume of rats is described. Using general anesthesia the heart was X‐rayed in the frontal and sagittal planes. The relative volume of the heart, calculated from the length, breadth and depth was multiplied by the correction factor of 0.44 to obtain the absolute volume. The correction factor has been estimated by empirical analysis in heart models. The relationship between length (a), breadth (b) and the square of depth (c). i.e c2/a×b; does not change during growth. The standard error of estimate for a single determination calculated from 168 duplicated determinations was 7.3 %.
Cardiac Output in Healthy Subjects Determined with a CO2Rebreathing Method
Authors: Jernérus R. , Lundin G. , Thomson D. 
Published: December 2008

AbstractThe cardiac output is measured with a CO2rebreathing method suggested by Defares(1956). The mixed vmous CO2pressure is determined graphically from the breath by breath‐determined CO2content in a rubber bag during rebreathing from the bag. Arterial CO2pressure is assumed to be the same as in end‐tidal air. CO2eliminated per time unit is measured by collecting the expired air in a Douglas bag and the cardiac output is determined with the Fick equation. For the CO2analysis a rapid infrared CO2metcr is used. The obtained values at rest are of the same size as those obtaincd with the Crollman acetylene method. The values from the work cxperiments arc of the same magnitude as those obainted with dye‐diliution or direct Fick methods. Stroke volume shows increasr from rrst to work about 60–80 per cent.
The Effect of Cold Exposure on the Catecholamine Excretion of Adrenalectomized Rats Treated with Reserpine
Authors: Johnson G. E. 
Published: December 2008

AbstractAdrenalectomizad rats subjected to moderate cold exposure showed a significant increase in noradrenaline excretion in urine. Adrenalectomized rats, treated with reserpine. howevar, failed to respond with an increase in the noradrenaline excretion during cold stress. A fall in the noradrenaline excretion of the reser‐pinized animals was usually followed by death. These results suggest that reserpine treatment inhibits the synthesis of noradrenaline in vivo and that the survival of moderately cold stressed adrenalectomized animals is related to the secretion of noradrenaline.
Effect of Adenine Nucleotides on Catecholamine Release and Uptake in Isolated Adrenergic Nerve Granules
Authors: Euler U. S. Von , Lishajko F. 
Published: December 2008

AbstractOn addition of 1–5 mM adenosine triphosphate (ATP) the spontaneous loss of noradrenaline from a suspension of adrenergic nerve granules is retarded or prevented. Adenosine diphosphate (ADP) exerts a similar effect while adenosine monophosphate (AMP) has little action. ADP and ATP also enhance the uptake of catecholamines from the incubation fluid. This effect is observed even with low amine concentrations in the incubation fluid in contrast to the uptake without addition of ATP. The ATP‐dependent uptake is inhibited by reserpine.
The Albumin Exchange in the Rabbit Eye
Authors: Bill Anders 
Published: December 2008

AbstractRed cells labelled with Cr51 and albumin labelled with I131 were given i. v. to unanesthetized rabbits. Additional doses of I131‐albumin kept the plasma concentration of labelled albumin at a steady value. At different times after the first injection the animals were killed and the eyes dissected. The red cell contents of the choroid, the anterior uvea and the retina were the same at all time intervals, while the apparent volume of the plasma equivalent albumin space in the tissues increased with time. The results were analyzed in terms of intravascular and extravascular albumin compartments having the same concentration of I131‐albumin as plasma. The apparent volumes of the extravascular plasma albumin compartments were: in the choroid 112 μl per g tissue, in the anterior uvea 94 μl per g tissue and in the retina 4.8 μl per g tissue. The apparent turnover rates for the albumin solution in the extravascular albumin compartments were: in the choroid 0.0847 μl per min, in the anterior uvea 0.234 μl per min and in the retina 0.0075 μl per min. It was calculated that the albumin concentration in the tissue fluid of the choroid and in that of the anterior uvea as a whole is more than tenfold the albumin concentration in the aqueous humour and that the albumin drainage with the aqueous humour can account for less than 10 per cent of the albumin drainage from the eye.
The Uptake and Excretion of Ca47 in Normal and Rachitic Rats
Authors: Bohr Hans H. 
Published: December 2008

AbstractThrough measurements of the uptake and the excretion of radioactive calcium, Ca47, in normal and rachitic rats it is shown that the reduced retention of Ca47 in the rachitic rats corresponds to an increased excretion in the urine due mainly to a higher specific activity in the blood. In previously rachitic rats treated with vitamin D almost normal values for retention and excretion as well as for the specific activity in the blood are obtained.
The Effect of Pyridinium Aldoximes and Atropine on the Incorporation of DF32P in Rat Liver Cell Fractions
Authors: ÅGren G. , Ramachandran B. V. 
Published: December 2008

AbstractThe incorporation of radioactive diisopropyl phosphorofluoridate (DF32P) in the subcellular fractions of rat liver cells has been studied when injected alone or followed or preceded by pyridine‐2‐aldoxime methane sulphonate (P28), N,N'‐trimethylene‐bis‐(pyridinium‐4‐aldoxime) (TMB‐4) and atropine. In experiments with only DF32P the total labelled phosphorus (32P) incorporated in the liver as well as the amounts taken up in the microsomal and mitochondrial fractions attain a maximum value in 20 min, but there is a considerable readjustment of 32P between the nuclear and supernatant fractions even at 60 min. The oximes administered prophylactically or therapeutically affect both the rate of uptake of DF32P and the quantity incorporated. The effects are explained on the basis of the rate of penetration of DF32P in the cell and possible direct action of the oximes. Atropine has a high retarding effect on the uptake of DF32P in the liver, the total quantity incorporated being reduced to 5–10% of the control in some experiments.
Experiments on Nervous Factors Controlling Respiration and Circulation During Exercise Employing Blocking of the Blood Flow
Authors: Asmussen Erling , Nielsen Marius 
Published: December 2008

AbstractDuring uninterrupted work on the bicycle ergometer the blood flow to the legs was suddenly interrupted by means of blood pressure cuffs. In the period with blocked circulation CO2 was added to the inspired air in such amounts that the alveolar PCO2 was maintained constant. The excess work O2‐uptake decreased up to 50%. The pulmonary ventilation, the pulse rate and the systolic blood pressure showed a steady and considerable increase. The cardiac output remained nearly constant with a tendency to decrease during the blocking period. The (a—v̄)O2‐difference and the mixed venous PCO2 consequently decreased considerably. These changes in respiratory and circulatory functions were well reproducible and the scattering of the values only small. It was concluded that the observed changes are neurogenic and caused by the increasing anaerobiosis in the blocked muscles. The nervous impulses involved may be elicited from muscle chemoreceptors, or they may stem from mechanoreceptors being activated through an observed recruitment of new motor units necessitated by the anaerobiosis.
Studies of the Relation Between the Frog's Electro‐Olfactogram (EOG) and Single Unit Activity in the Olfactory Bulb
Authors: Döving Kjell B. 
Published: December 2008

AbstractThe relationship between the frog's electro‐olfactogram (EOG) and the activity of single neurons in the olfactory bulb has been studied. In the absence of overt stimulation the units in the bulb exhibited a spontaneous activity with an average frequency of 0.7/sec. Butanol stimulation inhibited the activity of 65 per cent of the units investigated, 25 per cent were activated and 10 per cent reamined unaffected. Different types of odour gave different types of unitary response patterns. A standard odour mixture was more efficient in evoking inhibition than butanol alone. Some units were excited by low stimulus strength and inhibited by higher concentrations of odour. Units which were inhibited during odour stimulation frequently showed a post‐inhibitory excitation. The frequency of discharge of the activated units varied linearly with the amplitude of the EOG in the major part of the odour concentration range. The latency of the burst, measured from the start of the EOG, decreased from 400 to 100 msec with increasing stimulus strength. Adaptation was found to develop faster in the bulbar neurons than in the olfactory receptors.
Concentration of Lithium, Sodium and Potassium in Epithelial Cells of the Isolated Frog Skin during Active Transport of Lithium
Authors: Hansen H. Hvid , Zerahn K. 
Published: December 2008

AbstractThe distribution of Li, K and Na in different layers of the skin of Rana temporaria was investigated after active transport of lithium. During the transport period the skin was short‐circuited, and after it had been sectioned in the frozen state, the slices were weighed and analyzed for Li, K and Na It was found that:1. The concentration of Li was higher in the epithelial cells than in the outside solution for outside lithium concentrations of less than 10–20 mmole/1.2. This may be explained by assuming the inside of the epithelial cells negative with respect to the outside solution, and assuming the potential to be dependent on the outside concentration of lithium.
Spontaneous Junctional Activity of Fast and Slow Parietal Muscle Fibres of the Hagfish
Authors: Alnæs Egil , Jansen Jan K. S. , Rudjord Torstein 
Published: December 2008

AbstractThe spatial distribution, amplitude distribution and interval distribution of spontaneous Junctional potentials of fast and slow muscle fibres of the myotomal parietal muscle of the hagfish have been studied. The fast muscle fibres are focally innervated with an end‐plate area localized to one end of the fibre whereas the synaptic regions of the slow muscle fibres are distributed along their entire length. The mean distance between the synaptic sites of the slow muscle fibres is less than 0.1 mm. The electrical cable constants of the two types of fibre have been determined by passing square waves of current through the membrane and recording the changes in membrane potential. The specific resistance of the membrane of the slow fibres is unusually high.
The Effect of Heparin and ε‐Aminocaproic Acid on the Coagulation in Hypothermic Dogs
Authors: Johansson Bengt W. , Nilsson Inga Marie 
Published: December 2008

AbstractCoagulation studies were performed in 15 dogs subjected to cooling to 20° C under various conditions. Thrombocytopenia invariably occurred during the cooling process. Hypothermia alone was followed by decrease of fibrinogen and prothrombin and factor VII and by an increased fibrinolytic activity and antithrombin activity. Hyperactive factor V levels were recorded during hypothermia and the plasma also showed thromboplastic activity. Administration of e‐ACA to the dogs before and during the hypothermia prevented the development of fibrinolytic activity but it did not prevent the decrease of fibrinogen and prothrombin and factor VII. Hyperactive factor V levels were recorded during the cooling as well as a marked thromboplastic activity in the plasma. Administration of heparin to the dogs before and during the hypothermia prevented the decrease of fibrinogen. The fibrinolytic activity was not prevented. No hyperactive factor V levels occurred. Simultaneous administration of heparin and e‐ACA to the hypothermic dogs prevented both the decrease of fibrinogen and the fibrinolytic activity.It is concluded that the coagulation defects induced by hypothermia are due mainly to intravascular coagulation. The decrease of fibrinogen which takes place in connection with hypothermia is due to its consumption in the coagulation process and not caused by the fibrinolytic process. It appears unwise to use ε‐ACA alone during hypothermia.
Accumulation of Fluid in Exercising Skeletal Muscle
Authors: Jacobsson S. , Kjellmer I. 
Published: December 2008

AbstractLymph flow from, and volume changes in, muscles during exercise were recorded simultaneously. During exercise there occurs an outward filtration at an initially steady rate. This filtration gradually diminishes and finally ceases. Under the experimental conditions used lymph flow was very small compared with the rate of outward filtration. The capillary filtrate accumulated in the muscle. The amount of fluid accumulated varied with the work load. The factors limiting outward filtration are discussed. The most important limiting factors seem to be gradually rising tissue pressure, and to some extent changes in colloid osmotic pressure on either side of the capillary wall.
Contraction Properties of Intrinsic Laryngeal Muscles
Authors: Mårtensson A. , Skoglund C. R. 
Published: December 2008

AbstractThe contraction times of laryngeal muscles in the dog were found to differ from 14 and 16 msec for the thyroarytenoid and lateral cricoarytenoid muscles to 30 and 35 msec for the posterior cricoarytenoid and the cricothyroid muscles respectively. The same relation between the contraction times of fast and slow muscles was characteristic also of some other species investigated. The view is advanced that the short contraction time of the two sphincter girdle muscles primarily serves the purpose of closing the laryngeal aperture in protective larynx reflexes.The thyroarytenoid and cricothyroid muscles of dog, chosen as representatives of fast and slow muscle, were subjected to a more detailed analysis. Determinations of the active state plateau by the method of superimposition of tension curves from one and two stimuli gave values of 3.0–4.0 msec for the thyroarytenoid and 3.5–4.5 msec for the cricothyroid muscle. After determinations of the tetanus‐twitch ratios for the two muscles, the rate of decay of the active state could be estimated and was shown to be faster in the thyroarytenoid muscle. Tetanic direct stimulation showed that complete fusion may not occur until above 300 per sec in the cricothyroid and above 400 in the thyroarytenoid muscle.Analogous analyses performed by indirect stimulation of the fast and slow muscle gave very similar results with respect to mechanical separation time and fusion frequency. The results from an action potential analysis during short‐interval nerve stimulation are discussed from the point of view of the active state conception.
The Ascending Projections of Trigeminal Neurones in the Cat, Investigated by Antidromic Stimulation
Authors: Eisenman J. , Fromm G. , Landgren S. , Novin D. 
Published: December 2008

AbstractCats anaesthetized with nembutal were used. Antidromic responses were evoked in single trigeminal neurones by electrical stimulation of the contralateral trigeminal lemniscus (COTL) or the ipsilateral dorsal ascending trigeminal tract (IPDT) at the mesencephalic level. The neurones were localized to the main sensory nucleus (NVsnpr) or the rostral subdivision of the nucleus of the spinal trigeminal tract (NVspoγ) and classified in groups as described by Eisenman, Landgren and Novin (1963).An antidromic response was recorded from 48 per cent of the cells located in NVsnpr and classified as touch cells with small receptive fields or as whisker cells. The corresponding percentage for NVspoγ was 36. Gordon, Landgren and Seed (1961) found that 40 per cent of a similiar group of cells located in the caudal part of the nucleus of the spinal trigeminal tract was antidromically discharged from COTL. It may therefore be concluded that secondary tactile cells sending their axons into the ascending trigeminal paths are about equally common in the three parts of the trigeminal nucleus so far investigated.It was further observed, that secondary touch cells with small oral receptive fields, and located in the dorsomedial part of NVsnpr, sent their axons into IPDT, whereas secondary touch cells with small perioral or periorbital receptive fields, and located in the lateral and ventrolateral parts of NVsnpr or NVspoγ, projected into COTL. About 25 per cent of the trigeminal cells responding to nociceptive stimuli from large receptive fields were fired antidromically from COTL. In some trigeminal cells an antidromic response was evoked from the region of the red nucleus.
Disclosure of Labile Monoamine Fractions in Brain and Their Correlation to Behaviour
Authors: Häggendal Jan , Lindqvist Margit 
Published: December 2008

AbstractThe recovery rates of brain monoainines after disruption of long‐term treatment of rabbits with reserpine (0.2 mg/kg/day) and after single doses of the drug (0.2 and 1.0 mg/kg) have been compared. No clearcut difference in recovery rates between the two types of treatment could be detected. In both cases normal values were reached only after several weeks. From the 3rd to 4th day the animals showed a normal gross behaviour in spite of low monoamine levels. Brain monoamines and behaviour were studied in chronically treated rabbits during the 24 hours following the daily injection. A temporal correlation between the changes in the remaining low monoamine levels and behaviour was demonstrated, which is in contrast to observations made in animals receiving a single dose for the first time. It appears that chronic reserpine treatment results in removal of large physiologically inert monoamine fractions, thus disclosing small, labile, functionally essential fractions.