bluuebunny/crossref_metadata_2025 huggingface dataset:
Renal Vasoconstriction and the ‘Defense Reaction
Authors: Feigl Eric , Johansson Börje , Löfving Birger
Published: December 2008

Using the Horsley‐Clarke technique in cats, diencephalic structures were explored with stimulating electrodes. Venous outflows from the renal and skeletal muscle vascular beds were measured. Intense renal vasoconstriction was induced by hypothalamic stimulation in areas where sympathetic vasodilator fibres were activated. It is suggested that renal vasoconstriction is an integral component of the vascular adjustments which occur in the ‘defense reaction’.
The In Vivo Effect of Angiotensin on the Proximal Tubular Reabsorption of Salt in Rat Kidneys
Authors: Leyssac Paul P.
Published: December 2008

The purpose of the investigation presented in this report was to study the effect of angiotensin on the rate of proximal tubular reabsorption of filtrate in mammalian kidneys as evaluated from registration of the occlusion time, which is the time required from abruption of the renal circulation until the proximal tubules have completed reabsorption of the luminal filtrate. A direct momentary and rapidly reversible inhibitory effect of angiotensin is demonstrated the maximally depressed proximal reabsorption rate corresponding to the lowest rate observed in spontaneous variations of the glomerular filtration. The results indicate that a further depression of the glomerular filtration rate, below that corresponding to the. maximum effect of angiotensin, is caused by a reduction in the number of nephrons participating in urine formation. It is concluded that angiotensin, besides its vasoconstrictive effect, has a direct tubular inhibitory action, thus providing the two primary effects required for a hormonal regulator of renal blood flow, proximal reabsorption rate, and thereby of glomerular filtration rate.
Acute Changes in Capillary Filtration and Diffusion in Experimental Burn Injury
Authors: Arturson Gösta , Mellander Stefan
Published: December 2008

The effects of second degree burns on the resistance vessels, on the net transcapillary fluid movement and on the capillary filtration coefficient (CFC) were studied in the paw of the cat. In the acute phase of burn injury there was a pronounced dilatation of the resistance vessels, a very rapid loss of intravascular fluid to the injured tissue (edema formation) but only a moderate increase of the capillary filtration coefficient (reflecting capillary permeability). These findings indicate that the edema formation in the earliest phase of burn injury must be attributed mainly to some other factor than increased capillary permeability and the consequent leakage of plasma proteins into the tissue. Plasma osmolality in venous blood draining the region and “tissue fluid” osmolality were found to be increased significantly above the control levels during the early phase of burn injury. This seems to indicate that during burning a temporary transcapillary osmotic pressure gradient is established and that the early edema formation is mainly dependent upon a diffusion process which rapidly causes fluid to escape from the blood stream into the extravascular space of the burned tissue.
Presynaptic Inhibition from Contralateral Cutaneous Afferent Fibres
Authors: Eccles Rosamond M. , Holmqvist Birgitta , Voorhoeve P. E.
Published: December 2008

Depolarization of the cutaneous nerve terminals by volleys in any contralateral cutaneous nerve has been shown by three experimental procedures: by electrotonic spread of the depolarization along the dorsal root fibres; by intracellular recording from primary cutaneous afferents; and by excitability changes at the fibre terminations. These crossed presynaptic inhibitions were usually less powerful than those from the ipsilateral cutaneous nerves; and had a longer latency, 6 msec instead of 3; and a maximal effect at 30–50 msec instead of at 15–20 msec. Like in the ipsilateral cutaneous nerves, maximum effects with conditioning volleys in cutaneous fibres were obtained with volleys of about four times threshold.
Some Characteristics of the Proximal Tubular Wall Related to Reabsorption During Luminal Occlusion Following Interruption of Glomerular Filtration
Authors: Leyssac Paul P.
Published: December 2008

The purpose of this investigation was to study the hydrostatic pressure changes within and outside the proximal tubules and to study possible changes in proximal cellular volume during the occlusion period following abruption of the renal blood flow and filtration. The pressures were measured directly using the micropuncture technique. The results demonstrate that the proximal tubular wall can resist a modest positive hydrostatic pressure from either the inside or the outside of the cellular wall for a short time interval. During reabsorption in the occlusion period a positive pressure seems to be created in the lumen of the proximal tubules probably due to “interfacial tension” and a positive luminal pressure is maintained until all the fluid has disappeared.

The proximal cellular volume was estimated from the cellular area of cross‐sectioned proximal tubules of snap‐frozen kidneys. The area was measured by planimetry. It was demonstrated that the cellular area is the same (within about 10%) at the various rates of transcellular transport of sodium associated with spontaneous variations of the rate of glomerular filtration, and that it remains unchanged during the whole occlusion period. An increase of about 50% in the cellular volume occurred as soon as the luminal fluid was reabsorbed, i. e. about 20 sec after interruption of the renal circulation. The cellular volume then remained unchanged for several minutes.
Heart Rate and Blood Pressure Response to Occlusion of Visceral Arteries
Authors: Nissen Ole I.
Published: December 2008

In experiments on cats the heart rate response to occlusion of the visceral and carotid arteries has been investigated. Of 69 combined or separate occlusions of the coeliac and superior mesenteric arteries 6 produced a tachycardia, in 9 no change in heart rate occurred, in the rest a bradycardia occurred. Of 32 common carotid artery occlusions 2 produced a bradycardia, in 4 no change in heart rate was observed and in the rest a tachycardia was produced. The bradycardia during visceral artery occlusion is interpreted as a reflex elicited from the sinoaortic baroreceptors and caused by the rise in blood pressure. It is further observed that the pressure increments caused by visceral artery occlusion have a maximum at subnormal systemic pressures (between about 65 and 100 mm Hg). This is contrary to the blood pressure rise caused by carotid artery occlusion which as a rule is greater the greater the systemic pressure, in accordance with the threshold concept for the baroreceptors.

Therefore, at low systemic pressures (below about 110 mm Hg) a higher response to combined occlusion of the coeliac and superior mesenteric arteries than to carotid artery occlusion is the rule, the opposite is the case at higher systemic pressures.
The Effect of Some Physiological Vasodilators on the Vascular Bed of Skeletal Muscle
Authors: Kjellmer I. , Odelram H.
Published: December 2008

The effects of i. a. infused ACh, ATP, histamine and bradykinin (and kallidin) were studied on the isolated calf muscle preparation of cats and compared with the vascular response to graded exercise elicited by stimulating the sciatic nerve. With a plethysmographic technique the effects on the resistance vessels, the capillary filtration coefficient (CFC) and the capacitance vessels were assessed and through a more indirect approach the occurrence of an increased capillary permeability was estimated. All procedures decreased flow resistance. ACh and ATP increased CFC approximately as much as exercise and, like exercise, without any signs of increased capillary permeability. As a contrast bradykinin and particularly histamine produced higher CFC values at every degree of diminished flow resistance, together with other signs of increased capillary permeability. The increased permeability vanished as rapidly as the vasodilator response after infusion. ACh and ATP dilated the capacitance vessels but bradykinin, histamine and exercise did not. It is concluded: 1) that all procedures studied increase nutritional blood flow, 2) that bradykinin and histamine produce a promptly reversible increase of capillary permeability in the same doses that are needed for dilatation and 3) that none of the substances when infused i. a. could exactly reproduce the vascular response of exercise.
Differential Supraspinal Control of Inhibitory and Excitatory Actions from, the FRA to Ascending Spinal Pathways
Authors: Carpenter D. , Engberg I. , Lundberg A.
Published: December 2008

In the decerebrate state there is an effective tonic inhibition of transmission from the flexor reflex afferents (FRA) to ascending spinal pathways. The release from this tonic control after transverse lesions in the brain stem has been investigated with transmission to ventral spinal pathways. A low pontine lesion releases transmission of inhibitory actions from the FRA whereas a more caudal medullary lesion is required for the release of excitatory actions. This parallels what previously has been found with synaptic actions to motoneurones, and the differential release of inhibition and excitation from the FRA seems to be a general rule. The results are discussed mainly in relation to the functional significance of the excitatory and inhibitory actions from the FRA to ascending spinal pathways.
The Metabolism of Fatty Acids in the Rat II. Oleic Acid
Authors: Göransson Göran , Olivecrona Thomas
Published: December 2008

l‐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

The 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

Wistar 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

Respiration 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

A 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

The 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

It 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

Two 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

The 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

Antigen, 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

A 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

The 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

The 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

1‐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

In 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

Fex, 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

Nissen, 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

Ottoson, 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

Fahlén, 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.
Occurrence of Dihydroxyphenylalanine Decarboxylase in Nerves of the Spinal Cord and Sympathetically Innervated Organs
Authors: ANDÉN NILS‐ERIK , MAGNUSSON TOR , ROSENOREN EVALD
Published: December 2008

Andén, N. ‐E., T. Magnusson and E. Rosengren. Occurrence of dihydroxyphenylalanine decarboxylase in nerves of the spinal cord and sympathetically innervated organs. Acta physiol. scand. 1965. 64. 127–135. –After transection of the rabbit spinal cord the L‐3,4‐dihydroxyphenylalanine decarboxylase activity in the caudal part was reduced by 90–95 and 75–85 per cent when determined in vitro and in vivo, respectively. The drop appeared to be fastest between the second and fifth day, and the activity reached its minimum level after 3 weeks. In the rabbit iris the dihydroxyphenylalanine decarboxylase activity fell to approximately 10 per cent of that of the control side in 48 hours after the excision of the superior cervical ganglion. In both tissues the time courses of the disappearance of dihydroxyphenylalanine decarboxylase activity and of noradrenaline were very similar but the amine disappeared somewhat more suddenly and rapidly than the enzyme. Preganglionic sympathectomy did not influence the dihydroxyphenylalanine decarboxylase activity in the iris. The nerve trunk contained only 15–20 times higher activity than the iris, why the dihydroxyphenylalanine decarboxylase like noradrenaline probably occurs in the whole neuron but is highly concentrated in the terminals. Postganglionic sympathectomy reduced the dihydroxyphenylalanine decarboxylase activity in the rat submaxillary gland and spleen by 85 and 80 per cent, respectively.
Integrative Organization of the Rostral Spinocerebellar Tract in the Cat
Authors: OSCARSSON OLOV
Published: December 2008

Oscarsson, O. Integrative organization of the rostral spinocerebellar tract in the cat. Acta physiol. scand. 1965. 64. 154–166. – The convergence of synaptic actions from Group I muscle afferents and flexor reflex afferents (FRA) to rostral spinocerebellar tract (RSCT) neurones, and the effects produced in these neurones by natural stimulation of receptors have been investigated. The monosynaptic excitation from Group I afferents was related mainly or exclusively to tendon organ afferents. The convergence of Group I excitation to individual tract neurones was usually extensive: there was often excitation from one muscle group at each of the shoulder, elbow, and wrist and finger joints. The RSCT neurones received polysynaptic excitation from the FRA of large receptive fields in the ipsilateral forelimb. These fields had no obvious relation to the Group I receptive fields. The effects evoked by stimulation of cutaneous receptors were weak. The FRA effects from muscle were often strong; on maintained stretch there was only moderate adaptation and cessation of stretch was followed by an afterdischarge. The organization in the RSCT and VSCT (ventral spinocerebellar tract) is compared and the information forwarded by the two tracts is discussed. – Additional observations demonstrated that VSCT neurones were influenced from the FRA not only in hindlimb but also in forelimb nerves. There is a discussion of the significance of this finding for a hypothesis concerning the informative value of the FRA connections to ascending tracts.
The in Vivo Effect of Angiotensin and Noradrenaline on the Proximal Tubular Reabsorption of Salt in Mammalian Kidneys
Authors: LEYSSAC PAUL P.
Published: December 2008

Leyssac, P. P.The in vivo effect of angiotensin and noradrenaline on the proximal tubular reabsorption of salt in mammalian kidneys. Acta physiol. scand. 1965.64. 167–175. – The purpose of the investigation presented here was to study the immediate effect of angiotensin and of noradrenaline on the rate of proximal tubular reabsorption of filtrate in mammalian kidneys by a direct method. By registration of the occlusion time, which is the time interval between interruption of the renal circulation and the moment at which the majority of the proximal tubules have completed reabsorption of the luminal fluid, it is demonstrated that angiotensin causes a depression of the tubular reabsorption rate, which is maximal when about 0.7 × 10‐9g is acting per g of kidney. In contrast noradrenaline was without any immediate effect on the proximal reabsorption rate, suggesting that effects observed in clearance studies are indirect and mediated by a rapid intrarenal mechanism possibly involving the angiotensin system.
Distribution of Monoamines and Dihydroxyphenylalanine Decarboxylase Activity in the Spinal Cord
Authors: ANDÉN NILS‐ERIK
Published: December 2008

Andén, N. ‐E. Distribution of monoamines and dihydroxyphenylalanine decarboxylase activity in the spinal cord. Acta physiol. scand. 1965. 64. 197–203. – The contents of noradrenaline, 5‐hydroxytryptamine and DOPA decarboxylase activity at different levels of the rabbit and cat spinal cord have been investigated. The concentrations in the various parts differed only slightly and roughly parallelled the relative amounts of grey matter. There was more 5‐hydroxytryptamine than noradrenaline in all locations, usually 2–4 times. The distribution in the thoracic cord of cows has also been investigated. The concentrations of both amines were highest in the lateral horns, lower in the anterior and posterior horns, and much lower in the white matter. The DOPA decarboxylase activity was lower in the lateral horns than in the white matter and the other horns. No dopamine was normally found in the spinal cord.
The Effect of Dextran and Some other Colloids on the Suspension Stability of Blood from Different Species
Authors: ELIASSON R. , SAMELIUS‐BROBERG U.
Published: December 2008

Eliasson, R. and U. Samelius‐Broberg. The effect of dextran and some other colloids on the suspension stability of blood from different species. Acta physiol. scand. 1965. 64. 245–250. – The effect of various dextran fractions and plasma proteins on the suspension stability of blood from different mammals has been studied in vitro. The suspension stability was measured as erythrocyte sedimentation rate (ESR) according to Westergren's method. None of the compounds caused a change in ESR of blood from cow and sheep. The ESR of blood from cat and horse was increased by all compounds. Rat, rabbit, dog, pig and man formed an intermediate group.
The Transport Form of Free Fatty Acids in Rat Serum A study in vitro using gel filtration
Authors: GÖRANSSON GÖRAN
Published: December 2008

Göransson, G. The transport form of free fatty acids in rat serum. A study in vitro using gel filtration. Acta physiol. scand. 1965. 64. 269–274. – The partition of labeled fatty acids between the protein and water phases in rat serum has been studied in vitro using gel filtration on Sephadex G‐200 columns. Laurie, capric and caproic acids were to an increasing degree distributed over the total volume of the column, whereas all saturated fatty acids as well as unsaturated acids with a chain length of 14 carbon atoms or more were completely eluted in combination with protein. The saturated acids were, with increasing number of carbon atoms, to an increasing extent eluted with the lipoprotein fraction. More than 98 % of all the unsaturated fatty acids studied were eluted with the albumin peak. When the amount of oleic acid was increased above a mole ratio of total fatty acid to albumin of 3–6, the percentage of radioactivity recovered with the albumin fraction decreased.
Studies on the Peripheral Circulation and Metabolism in Man IV. Oxygen Utilization and Lactate Formation in the Legs of Healthy Young Men during Strenuous Exercise
Authors: PERNOW BENGT , WAHREN JOHN , ZETTERQUIST STAFFAN
Published: December 2008

Pernow, B., J. Wahren and S. Zetterquist. Studies on the peripheral circulation and metabolism in man. IV. Oxygen utilization and lactate formation in the legs of healthy young men during strenuous exercise. Acta physiol. scand. 1965. 64. 289–298. – 19 healthy young men exercised on a bicycle ergometer with increasing work loads. From indwelling catheters in the brachial artery and the femoral vein blood samples were drawn before, during and after exercise. The a–v O2 difference in the leg increased linearly in relation to heart rate and O2 uptake to a mean value of 163 ml/1 at maximal work. At this intensity (heart rate 180–195 beats per min) the mean value of the venous O2 saturation was 9 per cent. A linear relationship existed between log lactate and heart rate during work as well as between log lactate and O2 saturation of the femoral venous blood. The slope for the semilogarithmic regression of the femoral venous concentration of excess lactate (XL) on heart rate was significantly steeper than that of venous total lactate concentration. pH of venous blood decreased during exercise to a mean value of 7.09 at maximal load. A linear relation was obtained between decrease in pH and increase in lactate. The reproducibility of the abovementioned results was evaluated for 6 subjects. A comparison between exercise performed with one and two legs showed that heart rate increased almost identically in relation to O2 uptake at both types of exercise. The venous O2 saturation was somewhat lower at submaximal work loads during one‐leg exercise, while the final venous O2 saturation values at maximal work were almost identical. Lactate increased more rapidly during one‐leg exercise. These data seem to indicate that blood flow in relation to O2 demand is less adequate in one‐leg than in two‐leg exercise at comparable working intensities.
Studies on the Elimination of Exogenous Lipids from the Blood Stream The Kinetics of the Elimination of a Fat Emulsion Studied by a Constant Infusion Technique in Man
Authors: HALLBERG DAG
Published: December 2008

Hallberg, D. Studies on the elimination of exogenous lipids from the blood stream. The kinetics of the elimination of a fat emulsion studied by a constant infusion technique in man. Acta physiol. scand. 1965. 64. 299–305. – The earlier described kinetic principle for the elimination of a fat emulsion (Intralipid®) from the circulation studied after single injections was confirmed in this study, using a constant infusion technique. A primer dose of the fat emulsion, followed by a constant infusion, was given. The plasma triglyceride (TG) level was followed. The emulsion TG fraction in plasma was separated from endogenous plasma TG with a polyvinylpyrrolidone density gradient. At low infusion rates there was a constant TG level in the top fraction of the gradient containing the emulsion TG, indicating a first order removal. At high infusion rates there was a linearly increasing TG concentration in the top fraction, indicating a zero order removal. The data confirm equivocally the kinetic principle described earlier which consists of a maximal elimination capacity (zero order kinetic) at high concentrations and an exponential elimination rate (first order kinetic) at low concentrations. During the elimination of the emulsion TG fraction from the circulation changes were noted in the concentrations of the other TG fractions in plasma. Some data on these changes are also presented.
Inhibitory Action from the Flexor Reflex Afferents on Transmission to Ia Afferents
Authors: LUND S. , LUNDBERG A. , VYKLICKY L.
Published: December 2008

Lund, S. A. Lundberg and L. Vyklický. Inhibitory action from the flexor reflex afferents on transmission to la afferents. Acta physiol. scand. 1965. 64. 345–355. – In spinal cats the dorsal root potential (DRP) evoked from la afferents of flexors can be effectively depressed by volleys in the flexor reflex afferents (FRA). It has been confirmed that in the acute spinal cat volleys in la afferents of flexors give a primary afferent depolarization (PAD) in la afferents but not in lb and cutaneous afferents and that volleys in the FRA do not depolarize la afferents. Excitability measurements and intracellular recording from la afferents have shown that the PAD evoked from la afferents is depressed from the FRA. The presynaptic inhibition from la afferents of the la EPSP in motoneurones can be removed by volleys in the FRA. It is concluded that volleys in the FRA inhibit transmission from la to la at an interneuronal level possibly presynaptically through depolarization of interneuronal terminals. The findings are discussed in relation to the function of the gamma loop in the flexor reflex.
A Micromethod for the Determination of Carbon Monoxide in Blood
Authors: LINDERHOLM H.
Published: December 2008

Linderholm, H.A micromethod for the determination of carbon monoxide in blood. Acta physiol. scand. 1965.64. 372–376. – A method is described which makes it possible to determine small amounts of CO in gas and blood by the use of palladium‐molybdenum test tubes for the detection of CO. 0.05 ml of blood with normal COHb saturation (about 0.5 per cent) corresponding to a total amount of about 0.05 μl CO, is sufficient for an analysis of the CO content.
Direct Demonstration of the Systems of Terminals Belonging to an Individual Adrenergic Neuron and Their Distribution in Rat Iris
Authors: MALMFORS TORBJÖRN , SACHS CHARLOTTE
Published: December 2008

Malmfors, T. and Ch. Sachs. Direct demonstration of the systems of terminals belonging to an individual adrenergic neuron and their distribution in rat iris. Acta physiol. scand. 1965. 64. 377–382. –The adrenergic nerves remaining in the rat iris following the destruction of most nerve cells in the superior cervical ganglion were studied with the use of a histochemical fluorescence method. – The iris technique used have for the first time made it possible directly to demonstrate how the postganglionic adrenergic fibre, by branching within the innervated tissue, forms a system of long preterminal axons which run to different parts of the iris and how each preterminal axon finally forms a system of long and branching terminals (see Fig. 5). The systems of terminals that belong to an individual neuron are distributed to areas spread over a large part of the iris. The findings give direct evidence for the view of Hillarp (1946, 1959) as to the construction of the autonomic innervation apparatus. –The study also shows that one and the same neuron can give excitatory and inhibitory innervation respectively to two antagonistic effectors (dilator and sphincter).
Electrophysiological Investigation of the Gustatory Effect of Ethyl Alcohol I: The Summated Response of the Chorda Tympani in the Cat, Dog and Rat
Authors: HELLEKANT GÖRAN
Published: December 2008

Hellekant, G. Electrophysiological investigation of the gustatory effect of ethyl alcohol. I: The summated response of the chorda tympani in the cat, dog and rat. Acta physiol. scand. 1965. 64. 392–397. – The summated response of the chorda tympani nerve to alcohol is characterized by an initial depression, a slow onset of the discharge and then a strong positive response to a water rinse. The initial period of decreased activity is related to the alcohol concentration, in such a way that a stronger solution diminishes the period of depressed activity in the nerve. The increase of activity is greater in the cat and the dog than in the rat. This positive response in the cat and rat shows a maximum after which no further increase in the response can be observed with increased alcohol concentration. Evidence is presented that the strong response to water after alcohol emanates from gustatory fibres which respond positively to water. The possibility of rat gustatory responses to water and the types of gustatory fibres responsive to alcohol are discussed.
On the Occurrence of Tyramine in the Rabbit Brain
Authors: GUNNE LARS‐M. , JONSSON JOHN
Published: December 2008

Gunne, L.‐M. and J. Jonsson. On the occurrence of tyramine in the rabbit brain. Acta physiol. scand. 1965. 64. 434–438. – After chromatographic separation on a strong cation exchange resin no tyramine could be detected in an extract of 6 pooled rabbit brains. This indicates that the whole brain content of tyramine must be below 10 ng/g wet tissue weight. This observation does not support the concept that tyramine should be an important metabolic precursor of noradrenaline in the brain.