bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Metabolism of Fatty Acids in the Rat II. Oleic Acid
Authors: Göransson Göran , Olivecrona Thomas 
Published: December 2008

Abstractl‐C14‐Oleic acid and 9–10‐H3‐Palmitic acid in rat serum were injected intravenously to fasted and to refed male rats. The C14 and the H3 radioactivity in the tissue lipids was studied at various time intervals thereafter. The oleic acid label disappeared more rapidly from the blood FFA than did the palmitic acid label. The data indicate that oleic acid is more rapidly oxidized than palmitic acid. At short times a larger fraction of the C14 radioactivity than of the H3 radioactivity of the tissues was in the neutral lipid fraction, indicating that oleic acid is incorporated into this fraction to a larger extent than is palmitic acid.
Acid‐Base Changes in Diving Ducks
Authors: Andersen H. T. , Hustvedt B. E. , Lövö A. 
Published: December 2008

AbstractThe acid‐base status of ducks has been studied during prolonged diving. The rH of the arterial blood has been found to drop roughly 0.4 pH‐units during submersions lasting for 10–13 min. The pCO2 increases continuously during such a water immersion, but the total CO2 of the blood plasma rises only during the first few minutes and then falls, sometimes to sub‐resting values. This phenomenon has been attributed to the abrupt acidification of the blood.The large increase in the concentration of hydrogen ions in the blood is only partly caused by CO2‐retention, for it has been shown that as much 20 mM/l of non‐volatile acids may be added to the blood plasma during and after diving.
Glucuronidation in Rats of Different Ages and Strains
Authors: Huttunen J. K. , Miettinen T. A. 
Published: December 2008

AbstractWistar rats excreted more glucuronides into the urine than Sprague‐Dawley rats, both in the basal state and after oral menthol loading. The liver and kidney of the former strain had higher uridine diphosphate glucose dehydrogenase (UDPG dehydrogenase) and β‐glucuronidase levels than the corresponding organs of the latter strain. Uridine diphosphate glucuronyltransferase (UDP glucuronyltransferase) activity was also higher in the liver of Wistar than of Sprague‐Dawley rats, the situation being opposite in the kidney. The activity of UDP glucuronyltransferase was higher in the liver and kidney of young rats than of adult rats, the response produced by ethylene diamine tetra‐acetic acid (EDTA) in the liver being somewhat dependent on the age and sex of the animals. The activities of phosphatases destroying uridine diphosphate glucuronic acid (UDPGA), measured as the release of inorganic phosphate from UDPGA in the presence and absence of EDTA, differed only slightly in the different groups.
Comparative Aspects of the Respiratory Gas Exchange of Sea Urchins
Authors: Steen Johan B. 
Published: December 2008

AbstractRespiration of the sea urchin Strong ylocentrolus droebakiensis has been studied with measurements of oxygen uptake at different ambient temperatures and with parts of the surface organs selectively covered with wax. It was confirmed that the tube feet serve as the main respiratory organ. At 16°C the oxygen uptake is reduced if a small proportion of the tube feet surface area is covered or if the external oxygen tension is reduced. At 6°C a much larger decrease of podial area or tension is needed to reduce the oxygen uptake. The calculated oxygen uptake, based on podial dimensions and measured oxygen tension differences, is about ten times larger than the measured oxygen uptake. The inability of the sea urchin to utilize its theoretical respiratory capacity is tentatively explained as a consequence of its poorly developed circulatory system with the lack of a respiratory pigment. Comparison of the respiratory data from sea urchins with similar data from the eel reveal some trends in the evolution of respiratory mechanisms.
The Transmucosal Migration of Water and Hydrogen Ions in the Stomach
Authors: ÖBrink Karl Johan , Waller Margareta 
Published: December 2008

AbstractA preparation, consisting of an isolated flap of the ventral wall of a cat's stomach with an intact blood supply, was mounted between two perspex chambers. The transmucosal potential was measured. The mucosa was electrically shortcircuited and the current registrered. A mixture of HCl and Na2SO4 was instilled in the mucosal chamber and the disappearance rates for the hydrogen and sulphate ions were determined. The quotient between these two, Qm, was calculated. No stimulation to secretion of HCl was given, but a complete secretory rest could not be garanteed. A slight secretory activity tended to give too low values of Qm. The highest values of Qm coincided with a similar quotient for a cellophane membrane, Qc, which was considered to indicate that hydrogen ions disappeared through the gastric mucosa in the same way as did the sulphate ions, which were thought to migrate by way of an intercellular diffusion. The results were thought to support the diffusion hypothesis of Teorell. Similar experiments with tritiated water suggested that 75 per cent of the water migration is transcellular.
Further Studies of the Thyroidal Response to Local Cooling of the “Heat Loss Center”
Authors: Andersson B. , Brook A. H. , Ekman L. 
Published: December 2008

AbstractThe rise in plasma protein‐bound I131 (PBI131) which occurs during local cooling of the preoptic/anterior hypothalamic region in the goat was found to be accompanied by a corresponding rise in total serum protein‐bound iodine (PBI), confirming that such cooling may cause a conspicuous increase in thyroid hormone secretion. Experiments involving graded central cooling revealed that moderate cooling of the preoptic/anterior hypothalamic region was sufficient to elicit the full thyroidal response, whereas deeper cooling, in certain circumstances, may be completely ineffective. This suggests that the thyroidal response to such cooling reflects a true physiological mechanism operating already at a moderate general hypothermia. Local cooling of the “heat loss center” with the animal in a hot environment revealed that the thyroidal response is obtained even in the absence of peripheral cold inflow.
The Secretion of Adrenal Medullary Hormones During Hypoglycemia in Intact, Decerebrate and Spinal Sheep2
Authors: Crone Christian 
Published: December 2008

AbstractIt is not known from which part of the central nervous system the adrenal medulla is activated in hypoglycemia. The question was investigated in animals with various parts of the central nervous system removed, and the adrenal response was compared with that of intact animals. The amounts of adrenaline and noradrenaline in adrenal effluent blood were determined fluorimetrically. Intact animals showed increased secretion rate of adrenaline and to a lesser degree of noradrenaline in response to hypoglycemia. Decerebrate animals were capable of activating their adrenal medulla during hypoglycemia while spinal animals did not increase the rate of secretion above the resting level. It is, therefore, concluded that sympathetic neurones situated in the brain stem caudal to the hypothalamus are capable of activating the adrenal medulla in hypoglycemia. It proved very difficult to lower the blood glucose concentration in decerebrate animals despite the administration of large doses of insulin. The mechanism behind the insulin resistance of the decerebrate animal is discussed.
Blood‐Brain Barrier Alteration after Experimental Cold Injury of the Rabbit Brain, Indicated by Penicillin G in EEG and by Dye Tests
Authors: Flodmark Sigvard 
Published: December 2008

AbstractTwo previous known methods to indicate blood‐brain barrier alterations—intravital dye tests and EEG test after drug activation—were applied in parallel in 25 short‐or long‐term experiments on cold‐induced cerebral lesions in the rabbit. The method of cold application was a modification of that of Hass and Taylor, supplemented by a recording of the extradural temperature. A new type of permanent electrode for EEG recording is described. In 19 of 20 animals in which a structure‐deranging lesion was induced, a concomitant blood‐brain barrier alteration could be demonstrated. In 11 of these 19 expts. a complete correlation of the two methods of barrier indication was obtained (8 animals inconsistent results). In 6 animals in which no blood‐brain barrier alteration was induced a concordance of negative results with the two methods was also seen. Three to four days was the maximum duration of blood‐brain barrier damage noted among the 13 animals in which the tendency to restitution of barrier function was studied. The results are in conformity with those of previous investigators and seem to justify the use of normally‐barred EEG activating drugs such as penicillin, as detectors of blood‐brain barrier alteration. These drugs seem particularly suitable for iterative studies in living animals.
Effect of Light and Moderate Exercise on Alveolar‐Arterial O2Tension Difference in Man
Authors: Hesser C. M. , Matell G. 
Published: December 2008

AbstractThe effect of light and moderate exercise (400, 625, and 700 kpm/min) on the alveolar‐arterial O2tension difference (A—aD) in the sitting position was studied in healthy, young adults by comparing the mean alveolar and arterial gas tensions determined over a 3 min rest period and over the ensuing 5th and 6th min of exercise. Arterial gas tensions were obtained from continuous measurements of arterial pH, oxygen saturation, and temperature. Alveolar O2tension was calculated by the alveolar gas equation, substituting arterial for alveolar CO2. At all three levels of exercise the arterial PO2increased significantly by about 5mm Hg. In the experiments at 625 kpm/min, in which the respiratory exchange ratio (R) was also determined, A–aD decreased from a mean value of 14.7 mm Hg at rest, to 11.0 mm Hg during exercise. In the experiments at 400 and 700 kpm/min, where no ventilatory measurements were made in order to avoid interference with free respiration, it was found that, for the range of possible R values, the A–aD remained unchanged or decreased during exercise. The arterial O2deficit,i. e.the difference in O2content between pulmonary end‐capillary blood and systemic arterial blood, was calculated to decrease from a mean value of 0.27 vol‐% O2at rest, to 0.18–0.22 vol‐% O2during exercise. Likewise, the calculated total venous admixture to the systemic blood flow decreased from a mean value of 4.7 per cent of cardiac output at rest, to 1.7–1.8 per cent of cardiac output during exercise. All the above changes are ascribed mainly to a reduction of the virtual shunt created by uneven distribution of alveolar ventilation to pulmonary capillary blood flow.
Observations on 5‐Hydroxytryptamine and Histamine Release from Rabbit Platelets1
Authors: Westerholm Barbro 
Published: December 2008

AbstractAntigen, glycogen, n‐decylamine and phospholipase A were shown to cause simultaneous release of 5‐hydroxytryptamine (5‐HT) and histamine from rabbit platelets in vitro. There was no significant difference between the percentual release of 5‐HT and histamine. The release of 5‐HT was studied in greater detail. Release by antigen and glycogen both required the presence of plasma, occurred at similar rates and showed distinct temperature optima around 37° C. Heating the platelets to 47° C or plasma to 56° C produced an irreversible inhibition of such release. Heparin, EDTA, salicylaldoxime and the enzyme blocking agents ninhydrin (NHa group inhibitor) and allicin (SH group inhibitor) inhibited release. Reduced glutathione reversed the action of allicin. High concentrations of sodium chloride blocked antigen‐induced release, but did not significantly reduce release by glycogen. The results are considered to support the hypothesis that antigen and glycogen release 5‐HT and histamine from rabbit platelets by the activation of similar release mechanisms and that enzymatic processes could be involved. Release of 5‐HT by n‐decylamine and phospholipase A did not require the presence of plasma and could not be inhibited by treatments or agents found to inhibit or reduce release by antigen or glycogen. The mechanism by which n‐decylamine and phospholipase A cause 5‐HT and histamine release from rabbit platelets is considered to differ from that of antigen and glycogen.
Hyperpotassemia and Electrocardiographic Changes in the Duck during Prolonged Diving
Authors: Andersen Harald T. 
Published: December 2008

AbstractA conspicuous bradycardia and a series of characteristic changes in the electrocardiogram (ECG) may be observed when diving vertebrates submerge. The ECG‐changes include prolongation of the P—R interval with ultimate disappearance of the P‐wave, and an elevated and peaked T‐wave. These deviations from the normal ECG‐pattern indicate severe hyperpotassemia. It is reported in the present paper that the plasma potassium concentration actually do increase during prolonged underwater exposure. The relationship between the ECG‐changes observed during submersion and the hyperpotassemia is discussed.
Some Quantitative Considerations on Vagally Induced Relaxation of the Gastric Smooth Muscle in the Cat
Authors: Jansson G. , Martinson J. 
Published: December 2008

AbstractThe vagus nerves of the cat contain two sets of efferent fibres affecting gastric motility. These two sets can be distinguished from one another by the difference in their stimulation thresholds. The low‐threshold fibres elicit pure motor responses; the high‐threshold ones, a long‐lasting relaxation of the stomach wall. This vagally induced gastric relaxation, which seems to be confined largely to the corpus and fundus, may sometimes be extreme. When recording gastric volume changes at a constant, low transmural pressure (2–3 cm H2O), stimulation of the inhibitory fibres can increase the volume several hundred per cent. Under these conditions the fundal muscle fibres may increase by 40 % or more in length. Essentially maximal relaxation of the stomach wall can apparently be brought about by stimulation of these inhibitory fibres. It would appear that this powerful relaxing effect of the vagal fibres on gastric muscle is involved in the ‘receptive relaxation’ of the stomach.
External Intercostal and Phrenic a Motor Responses to Changes in Respiratory Load
Authors: Corda M. , Eklund G. , Euler C. v. 
Published: December 2008

AbstractThe hypothesis that the fusimotor—muscle spindle system in its control of physiologically induced movements automatically adjusts the a motor activity to achieve“wanted” length changes in spite of some variations in load that may occur has been examined for the respiratory movements of external intercostal muscles and the diaphragm after bilateral vagotomy in cats under light pentobarbital anaesthesia. The afferent activity from intercostal muscle spindles increased in response to an increase in respiratory load produced by tracheal occlusion. Efferent intercostal a motor activity was reflexely enhanced in response to such an increase in load, an effect which was abolished after section of the dorsal roots of the same and adjacent segments. The efferent phrenic a motor activity and the electrical activity of the diaphragm did not show this response to tracheal occlusion indicating a principal difference in proprioceptive control of the external intercostal muscle and the diaphragm.
The Metabolism of Fatty Acids in the Rat IV. Stearic acid
Authors: Göransson Goran 
Published: December 2008

Abstract1‐C14‐Stearic acid and H3‐palmitic acid in rat serum were injected i. v. into fasted and refed male rats and the disappearance of radioactivity from the blood, its tissue distribution and recirculation into the blood were studied. Stearic acid was taken up at a lower rate than palmitic acid. Five minutes after the injection about the same total amount of C14‐as of H3‐label was recovered from the fasted rats. At 320 min more C14‐label was left. This may be due to the less rapid turnover of the Stearic acid‐containing phospholipids compared to the glycerides. In the liver there was a marked preferential incorporation of stearic acid into the phospholipids, whereas the ratio of incorporated stearic acid to palmitic acid in the glycerides was low. This skewed distribution was also seen in the blood phospholipids and the blood glycerides.
A Strychnine‐Resistant Postsynaptic Inhibition in the Spinal Cord
Authors: Kellerth Jan‐Olof 
Published: December 2008

AbstractIn cats anaesthetized with pentobarbitone lumbar motoneurones were impaled with potassium citrate microcapillaries. The inhibitory influence from muscle stretch receptors on the motoneurones was studied. Attention was paid to the following criteria: 1) mono‐synaptic excitability, 2) firing rate during stimulation by depolarizing transmembrane current, 3)“synaptic activation noise” and 4) shift of average membrane potential. A postsynaptic inhibition is described which is insensitive to convulsive doses of strychnine. This strychnineresistant postsynaptic inhibition was frequently found. So‐called presynaptic inhibition was never observed.
Auditory Activity in Uncrossed Centrifugal Gochlear Fibres in Cat A Study of a Feedback System, II
Authors: FEX JÖRGEN 
Published: December 2008

AbstractFex, J., Auditory activity in uncrossed centrifugal cochlear fibres in cat. A study of a feedback system, II. Acta physiol. scand. 1965. 64. 43–57. – In decerebrate cats all of the cochlear efferents except the uncrossed olivo‐cochlear fibres were cut, the vestibulo‐cochlear anastomosis was exposed through the vestibule and single unit activity was recorded in, and close to, the anastomosis with micropipette electrodes. Although the auditory function was destroyed in the dissected cochlea, resting activity was found in primary auditory afferents, suggesting that synaptic mechanisms could still be intact in such a preparation. – Uncrossed olivo‐cochlear fibres were activated by electrical stimulation of the ipsilateral cochlear nerve and by acoustic stimulation of the contralateral ear. When activated by sound, the uncrossed efferents in the basal fascicle of the anastomosis generally responded to higher tone frequencies than did fibres in the apical fascicle, which suggests that afferents and uncrossed efferents from homotopic cochlear points in opposite cochleae are connected. The fibres responded characteristically with a low, regular firing rate without an initial burst and with a long latency at threshold, indicating that their input would be integrated over a considerable time. Many of the efferents showed resting activity which, with few exceptions, could be inhibited by sound depending on the choice of tone frequency. – The findings suggest that the uncrossed cochlear efferents and ipsilateral auditory afferents together form an auditory, closed feedback loop, which is directly influenced by the contralateral ear and support the hypothesis (Fex 1962) that the uncrossed and the crossed olivo‐cochlear bundles together form a complex, auditory feedback mechanism.
The Magnitude of the Skimming Phenomenon in the Interlobular Arteries of the Cat Kidney
Authors: NISSEN OLE I. 
Published: December 2008

AbstractNissen, O. I. The magnitude of the skimming phenomenon in the interlobular arteries of the cat kidney. Acta physiol. scand. 1965. 64. 87–92. – Samples simultaneously collected from the arterial system, from the deep renal veins and from the subcapsular renal veins in the cat kidney have been analysed with respect to red cell volume, plasma proteins, plasma osmolality (and plasma PAH). The ratio: subcapsular venous concentration/arterial concentration was on an average 1.10 for the red cells, 1.09 for the plasma proteins, and 0.99 for plasma osmolality. The ratio: deep venous concentration/arterial concentration was on an average 0.90 for the red cells, 0.89 for the proteins, and 1.03 for the osmolality. The difference between the protein ratios and a part of the difference between the hematocrit ratios may be attributed to the fact that a part of the fluid lost by ultrafiltration from the blood traversing the outer cortex is reabsorbed in the loops of Henle and the collecting ducts and thus will be added to the blood leaving the kidney by way of the deep veins. A smaller part of the difference between the hematocrit ratios may be explained from the alterations in the tonicity of the blood during its passage through the kidney.
The Effect of Osmotic Pressure Changes on the Isolated Muscle Spindle
Authors: OTTOSON D. 
Published: December 2008

AbstractOttoson, D. The effect of osmotic pressure changes on the isolated muscle spindle. Acta physiol. scand. 1965. 64. 93 105.– The action of hypertonic and hypotonic solutions on the sensory endings of the muscle spindle has been studied in isolated preparations. It was found that changes of osmotic pressure by more than 25 per cent caused an augmentation of the activity of the resting spindle and modified its sensitivity to stretch. Increase of pressure produced a discharge the peak frequency of which increased linearly with osmotic strength. The maximum effect was usually obtained with concentrations of four to five times that of Ringer's solution. The responsiveness of the spindle to stretch decreased with increasing pressure. Decreasing the osmotic pressure produced a short‐lasting increase of the activity of the resting spindle followed by a decline and final cessation of the discharge. The responsiveness to stretch was increased during the period of repetitive firing and then decreased. Washing with Ringer's solution after immersion in hypotonic solutions regularly produced a prolonged discharge and a reduced sensitivity to stretch. It is concluded that the observed changes are mainly due to osmotic effects on the sensory endings of the spindle. The results suggest that the endings behave as simple osmotic sacs within a limited range of osmotic strengths and that the sensory membrane is equally sensitive to distention and folding.
Monoamines in the Swimbladder of Gadus callarias and Salmo irideus
Authors: FAHLÉN G. , FALCK B. , ROSENGREN E. 
Published: December 2008

AbstractFahlén, G., B. Falck and E. Rosengren. Monoamines in the swimbladder of Gadus callarias and Salmo irideus. Acta physiol. scand. 1965. 64. 119–126.–The noradrenaline in the swimbladder of the cod and the rainbow trout is stored in short adrenergic neurons whose perikarya are located in close relation to the swimbladder itself. In the cod, the noradrenergic neurons are innervated by noradrenergic neurons that arise from the coeliac ganglion of the sympathetic chain. A hitherto unknown system of epithelial cells storing 5‐hydroxytryptamine was observed in the trout swimbladder.