bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Metabolism of Fatty Acids in the Rat
Authors: Göranssn Göran , Olivecrona Thomas 
Published: December 2008

AbstractGöransson, G. and T. Olivecrona. The metabolism of fatty acids in the rat. I. Palmitic acid. Acta physiol. scand. 1964. 62. 224–239. — Data on the concentration and the fatty acid composition of neutral lipid fatty acids and of phospholipid fatty acids in blood, liver, heart, kidney, lung, spleen and muscle from fasted and refed male rats are reported. Data are also given on the radioactivity in these tissue lipid fractions at several time intervals after the intrevenous injection of 9–10‐H3‐labeled palmitic acid in rat serum. These data are intended as a reference for further studies on the metabolism of other long‐chain fatty acids. The data are discussed with reference to a general picture of the metabolism of the plasma FFA after their removal from the plasma. After entering the tissues the FFA are oxidized, converted to other long‐chain fatty acids, esterified or transferred back to the plasma. The fractions diverted into the different pathways depend upon the nutritional state. The fraction oxidized is larger in the fasted than in the refed rats. The diversion into one or the other of the possible pathways occurs almost immediately after the FFA have entered the tissue. Subsequently, the remaining labeled fatty acids are metabolized at considerably lower fractional rates since they have entered larger fatty acid pools, than the plasma FFA pool.
Circulatory and Respiratory Adaptation, during Long‐Term, Non‐Steady State Exercise, in the Sitting Position1
Authors: Ekelund L. G. , Holmgren A. 
Published: December 2008

AbstractEkelund, L. G. and A. Holmgren.Circulatory and respiratory adaptation during lone‐term, non‐steady state exercise in the sitting position. Acta physiol. scand. 1964.62. 240–255. — Circulatory and respiratory changes during long‐term, non‐steady state exercise in the sitting position was studied with heart catheterization technique in six healthy young men with average training. The work load was chosen individually to increase the heart rate to about 140–150 beats per minute after 10 min work and to 170–180 beats per min after 60 min work.The circulatory changesduring these experimental conditions were characterized by continuously falling systemic arterial blood pressure, constant cardiac output, and increasing heart rate, indicating a continuously fallinn stroke volume. The blood volume was lower during exercise than at rest in the supine position but remained unchanged between 10 and 50 min work. Theacid‐basestatus was characterized as a compensated metabolic acidosis, which remained essentially constant throughout the test. Therespiratory responsewas characterized by a successively increasing total ventilation, a moderate increase in alveolar ventilation and a marked increase in dead‐space ventilation. The increase in total ventilation was effectuated by an increase of both the respiratory rate and the tidal volume. The overallventilation‐perfusion relationshipshowed a slight continuous increase. Both circulatory and respiratory changes may be explained in the light of a gravitational shift in the distribution of the blood volume.
The Effect of Graded Stimulation of Efferent Vagal Nerve Fibres on Gastric Motility
Authors: Martinson Jan 
Published: December 2008

AbstractMartinson, J. The effect of graded stimulation of efferent vagal nerve fibres on gastric motility. Acta physiol. scand. 1964. 62. 256–262. — The gastric motor responses to efferent vagal stimulation of varying frequency and impulse duration were studied in cats. The efferent fibres, both excitatory and inhibitory, exert their maximum effect on stimulation by an impulse rate of about 10 imp/sec. Higher frequencies producing little, if any, further effect. The stimulation thresholds of the excitatory and inhibitory fibres depend only on the strength and duration of stimulation pulses and not on their frequency, so that high frequency‐stimulation is not equivalent to high‐intensity stimulation, i. e. stimulation with long‐duration pulses, regarding its ability to produce gastric motor inhibition. The findings argue against the inhibition observed being produced by overflowing transmitter substance from aberrant sympathetic vasomotor nerve fibres running in the vagal supply to the stomach.
Collateral Blood Flow in the Myocardium of Dogs Measured with Krypton85
Authors: Johansson Borje , Linder Erland , Seeman Torsten 
Published: December 2008

AbstractJohansson, B., E. Linder and T. Seeman.Collateral blood flow in the myocardium of dogs measured with Krypton85. Acta physiol. scand. 1964.62. 263–270. — Methods have recently been developed for determination of regional blood flows from wash‐out curves recorded externally after close‐arterial injection of radioactive Krypton (Kr85). In the present study this technique has been applied to measurement of collateral capillary blood flow in the myocardium of dogs during acute occlusions of coronary arteries. A monoexponential fall in activity was found during elimination of Krypton from the normal myocardium indicating a homogeneous distribution of blood flow. The wash‐out curves recorded during coronary occlusions could be dissolved into two separate components. There was a rapid phase related to the elimination of Krypton from normally perfused regions of the myocardium and a slow phase due to the de‐saturation of the ischemic portion. The magnitude of the collateral capillary blood flow was determined from the decay rate of the slow component. The relative size of the ischemic region could be estimated from the zero time values of the two phases. Collateral blood flow seemed to be fairly homogeneously distributed within the ischemic part of the myocardium. Release of an occlusion was followed by a rapid fall in activity in association with the reactive hyperemia.
Iron Exchange between Transferrin and the Placenta in the Rat
Authors: Laurell Carl‐Bertil , Morgan Evan 
Published: December 2008

AbstractLaurell, C.‐B. and E. Morgan. Iron exchange between transferrin and the placenta in the rat. Acta physiol. scand. 1964. 62. 271–279. — The process of iron exchange between transferrin and the placenta was studied in vitro using 59Fe, rat serum or purified rat transferrin labelled with 131I and placental tissue. The yolk sac placenta bound more transferrin and took up iron more rapidly than did the allantoic placenta. The amount of transferrin bound increased rapidly for the first 15 minutes but thereafter showed little further increase: the amount bound increased as the transferrin concentration was increased but was unaffected by the degree of its saturation with iron. Iron uptake increased steadily during incubation, was greater when the iron concentration was increased, but was unaffected by increasing the transferrin concentration with a constant iron concentration. The release of iron from placenta was slower than that of transferrin and was less into a transferrin‐free solution than into plasma. The intravenous injection of rat transferrin in amounts sufficient to approximately double the plasma concentration did not alter the subsequent transfer of 59Fe from maternal plasma to the fetuses. The results show that the mechanism of iron exchange between transferrin and rat placenta is very similar to that between transferrin and reticulocytes.
Reflex Influence of “Somatic Pressor and Depressor Afferents” on Resistance and Capacitance Vessels and on Transcapillary Fluid Exchange
Authors: Johansson Börje , Lundgren Ove , Mellander Stefan 
Published: December 2008

AbstractJohansson, B., O. Lundgren and S. Mellander. Reflex influence of “somatic pressor and depressor afferents” on resistance and capacitance vessels and on Tran capillary fluid exchange. Acta physiol. scand. 1964. 62. 280–286. — The reflex circulatory effects of afferent somatic nerve stimulation were studied in the different consecutive vascular sections in skeletal muscle and intestine. In skeletal muscle the “somatic pressor reflex” elicited constriction of resistance and capacitance vessels and increased the pre‐/postcapillary resistance ratio while precapillary sphincter tone was unchanged. In the intestine there was reflex constriction of capacitance and precapillary sphincter vessels but only transient changes in the resistance function. In a situation of increased vasoconstrictor fiber activity produced by carotid occlusion stimulation of “somatic depressor afferents” elicited dilatation of resistance and capacitance vessels in both skeletal muscle and intestine. Carotid occlusion produced continuous absorption of fluid from the extravascular space in skeletal muscle due to a fall in capillary pressure. A superimposed stimulation of somatic depressor afferents was able to restore capillary pressure to the control level despite incomplete restoration of total resistance and capacitance functions. A dilatation of precapillary sphincters occurred in intestine but apparently not in skeletal muscle during the somatic depressor reflex.
STUDIES ON 5‐HYDROXYTRYPTAMINE STORES IN PINEAL GLAND OF RAT
Authors: BERTLER ÅKE , FALCK BENGT , OWMAN CHRISTER 
Published: December 2008

Summary— The pineal gland of the rat has been studied using a highly specific and sensitive fluorescence microscopical method for the cellular localization of certain biogenic monoamines, in combination with fluorimetric determinations of 5‐hydroxytryptamine (5‐HT) levels under normal and experimental conditions. Exceptionally large amounts of 5‐HT have been found in the gland. This amine is located partly in the parenchymal cells and partly in the pineal sympathetic nerves. There is strong evidence to support the view that the sympathetic nerves are noradrenergic, but take up 5‐HT from the parenchymal cells into their terminal portions, which run within the gland. A unique feature thus exists in the sympathetic nerves of the rat's pineal in that they contain two different monoamines.The experiments have shown that half of the pineal 5‐HT is located in the sympathetic nerves, and that the rest is stored in the parenchyma. A small portion of this parenchymal pool is dependent on an intact innervation and is lost on denervation. After the injection of noradrenaline, the fluorescence of the pineal nerves changes to show the characteristics of a catecholamine. Half of the pineal 5‐HT is then depleted, showing that the neuronal 5‐HT is replaced by the administered noradrenaline. No change can be registered in pineal 5‐HT levels 22 hours after the administration of α‐methyl‐m‐tyrosine. However, metaraminol causes a pronounced depletion of pineal 5‐HT. A reaccumulation of the 5‐HT fluorescence in the pineal nerves can be brought about by the injection of nialamide to reserpinized animals, as it occurs in the cerebral nerves containing 5‐HT.
Range of Sympathetic Discharge and Reflex Vascular Adjustments in Skeletal Muscle during Hemorrhagic Hypotension
Authors: Lundoren Ove , Lundwall Jan , Mellander Stefan 
Published: December 2008

AbstractLundgren, O., J Hemorrhage is associated with an increase in the sympathetic vasoconstrictor fiber discharge to skeletal muscle, ranging from values below 1 imp/sec up to about 7 implsec, the rate of discharge being related to the extent of bleeding. The reflex increase in sympathetic activity is, as a rule, fairly well maintained during prolonged hemorrhage. Normally, this elicits a reflex constriction of resistance and capacitance vessels and an increase in the pre‐/post‐capillary resistance ratio leading to decreased capillary pressure and absorption of extravascular fluid. The constriction of the capacitance vessels and the fluid absorption both tend to compensate for the reduction of intravascular fluid volume in the early phase of hemorrhage. However, there is a gradual decline in the reflex vascular response, despite maintained vasoconstrictor fiber discharge, evidently due to competitive action of locally produced dilator factors. This decline is more pronounced the more severe the reduction in muscle blood Row accompanying hemorrhage. The decline is more pronounced in the precapillary vessels than in postcapillary vessels. Therefore, in the later stages of hemorrhage the pre‐/postcapillary resistance ratio may decrease to such an extent that fluid escapes from the circulation by filtration, leading to further derangement of cardiovascular function.
The Effect of Parathyroid Hormone and Vitamin D on Serum Calcium in Rats
Authors: Toverud Svein Utheim 
Published: December 2008

AbstractConflicting evidence exists regarding the hypothesis that vitamin D is essential for the calcium‐mobilizing action of parathyroid hormone. A re‐investigation was undertaken by feeding weanling vitamin D‐deficient rats a vitamin D‐free diet containing 0.7 % calcium and 0.6 % phosphorus (diet D,) for 3 weeks. At day I, when the mean serum calcium level was 7.1 mg/100 ml, the diet was replaced by 10 % glucose in saline. Different groups received either A) 100 I.U. vitamin D on day 2; B) injections of 200 and 100 units parathyroid extract (PTE) on days 4 and 5, respectively; C) a combination of treatments A and B; or D) saline injections. The serum calcium levels, determined 6 hours after the last PTE injection, permitted calculation of mean individual increase expressed in mg/100 ml: A) + 1.04, B) + 0.86, C) + 2.58, D) – 0.57.Continuous feeding with diet D, or one containing less protein resulted also in a significant response to PTE. Parathyroidectomy, but not sham operation, resulted in a substantial fall in serum calcium in rats fed diet D.,The conclusions are: 1) The calcium‐mobilizing action of parathyroid hormone in the rat is either independent of, or requires only minute amounts of, vitamin D. 2) At the one dose level investigated, no evidence for interaction between the effects of vitamin D and parathyroid extract was found when intestinal calcium absorption was minimal.
Renal Vasoconstriction and the ‘Defense Reaction
Authors: Feigl Eric , Johansson Börje , Löfving Birger 
Published: December 2008

AbstractUsing 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

AbstractThe 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

AbstractThe 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

AbstractDepolarization 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

AbstractThe 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

AbstractIn 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

AbstractThe 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

AbstractIn 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.