bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Influence of the Nigro‐Neostriatal Dopamine Pathway on Spinal Motoneuron Activity
Authors: Andén Nils‐erik , Larsson Knut , Steg Göran 
Published: December 2008

AbstractReserpine treatment of rats with a unilateral lesion of the nigro‐neostriatal dopamine neurons produced on the unoperated side a rigidity which could be demonstrated electromyographically in the calf muscles. There was also a more marked increase in the a‐ and a decrease in the γ‐motoneuron excitability on the side contralateral than ipsilateral to the lesion indicating that the nigro‐neostriatal dopamine neurons influence muscle tone by causing a shift of the balance between the α‐ and γ‐motoneuron activity.
The Effect of Protriptyline on Uptake and Retention of dl‐3H‐Nor adrenaline in Different Tissues of the Rat
Authors: Almgren Olle , Jonason Jan 
Published: December 2008

AbstractThe inhibition of3H‐noradrenaline (3H‐NA) uptake in submaxillary glands, spleens and heartr of the rat was studied after pretreatment of the animals with different doses of protriptyline (PTP). One μg/kg3H‐NA was administered intravenously 15 min after the intraperitoneal injection of PTP. The duration of the uptake blockade induced by 10 mg/kg PTP was also studied. To circumvent problems due to the blood flow, anin vitrotechnique was also used to compare the uptake and retention of3H‐NA in submaxillary glands and hearts. It was found that the3H‐NA uptake of the heartin vivonormally exceeds several times that of the submrtvillary glands, whilein vitrothe uptake was directly correlated to the concentration of endogenous NA. The data support the view that the greater blood flow through the heart is responsible for the major part of the difference foundin vivo. After PTP pretreatment the uptake inhibition was much stronger in the heart than in the other organs investigatedin vivo. Alsoin vitrothere was a more efficient inhibition of the3H‐NA uptake in the heart than in the submaxillary gland, both when 10 mg/kg PTP was given i.p. lo the animals 30 min prior to death and when 1μg/ml of the drug was present in the incubation medium. The factors deter mining the overall sensitivity of different organs to PTP are discussed.
Fibrinogen Degradation Products in Experimental Intravascular Coagulation Gel filtration and immunological studies
Authors: Zetterqvist Eric 
Published: December 2008

AbstractDogs injected with 125I‐fibrinogen were given: 1. a thrombin infusion during 1 hr, and 2. simultaneous infusions of epsilon aminocaproic acid (EACA) and thrombin, respectively. Platelet number, fibrinogen concentration and radioactivity in plasma, fibrinogen and serum were determined. Special comparative studies were made between one dog given thrombin and one given EACA together with thrombin. Samples obtained before and at 2 hrs after the start of the thrombin infusions were analyzed with respect to the radioactivity distribution in the blood and in plasma after Sepharose and Sephadex flitrations. Trials were made to identify the fibrinopeptides. The immunological behaviour of serum and of eluate fractions was studied. An occurrence of fibrinolysis in the dogs already before the thrombin infusions was indicated. After the thrombin infusions there was in plasma a wide variety of fibrinogen degradation products with the antigenic determinants of fibrinogen. No products with higher molecular weight than that of fibrinogen were demonstrable. When EACA was given together with thrombin there was an inhibition of degradation products. The results give further support for a secondary fibrinolysis in intravascular coagulation. No evidence was obtained for the occurrence of fibrinopeptides.
Effects of Parasympathomimetic Agents and Vagal Stimulation on the Flow in the Pancreatic Duct of the Cat
Authors: Lenninger Sven 
Published: December 2008

AbstractIntravenous injection of methacholine and vagal stimulation increased the amount of juice secreted by the secretin‐stimulated pancreas of the cat. The increase was greater at low rates of secretion than at high. Methacholine and vagal stimulation as well as secretin retarded the flow of a salt solution, perfused through the gland. It is concluded that the cholinergic stimulation causes the gland to secrete but also increases the resistance to the flow in the duct, probably by luminal narrowing and by changes of the fluidity of the juice.
Pulmonary Transcapillary Exchange of 24Na and 51CrEDTA. An Evaluation of Factors Influencing the Extraction of these Tracers during one Passage through an Isolated Lung Preparation
Authors: Nicolaysen Gunnar 
Published: December 2008

AbstractExperiments with the single injection indicator diffusion method have been carried out in an isolated, ventilated and plasma‐perfused rabbit lung preparation. A mixture of two diffusible tracers (24Na, 51CrEDTA) and one intravascular reference tracer (125I‐albumin) were used. Relative concentrations in the first indicator‐containing venous outflow fractions collected indicated that there had been some initial extraction of the diffusible indicators. A small extra‐vascular space of distribution appeared to represent the most important determinator for the extent of this initial extraction during one single passage through the vascular bed. Results from several types of experiments were consistent with there being also some moderate degree of diffusion limitation for the extraction of the diffusible tracers. Extraction of the diffusible tracers appeared to be moderately increased when the intravascular concentrations of both Ca++ and Mg++ were reduced to such low levels that edema was developing in the preparation. It appears unlikely though that the single injection indicator diffusion method in its present form can yield more detailed information on capillary permeability to small solutes in this rabbit lung preparation.
Spatial Specificity of Local Habituation to Cold
Authors: Eide R. 
Published: December 2008

AbstractA series of daily cold exposures of 9 cm of the tail of 6 rats for 50 min for 17 days resulted in a significant reduction in the cardio‐acceleration to the cooling. This is conceived as habituation. When an additional 3 cm of the tail was immersed on the 18th day, the cardiac reaction increased markedly, showing that the habituation was specific to the part repeatedly exposed. A control experiment showed that this return of reaction was not a result of spatial stimulus summation. A smaller group of rats were exposed for 40 days with similar results. In a second series of experiments the ventral half of 3 cm of the tail of 8 rats were exposed to cold one hour a day for 17 days. A reduced cardio‐acceleration was found. Stimulation of the dorsal part of the same segmental area resulted in renewed cardio‐acceleration. This seems to indicate some degree of somatotopic organization of the habituation process.
A Fifth Modality of Taste
Authors: Andersen H. T. , Hartmann Å. O. 
Published: December 2008

AbstractAn analytical search for independent modalities of taste is presented. The correlation matrix between independent stimuli was calculated using data recorded from chorda tympani single fibres in rats (Erickson, Doetsch and Marchall 1965) assuming that specific taste sensations may be explained by an “across fibre pattern” input into gustatory primary afferents. The four main factors were first rotated since this number of factors would correspond to the common idea of four independent taste primaries; bitter, salty, sour and sweet. The corresponding re solution of stimuli on four factors was inadequate. However, by adding one more factor a striking separation on five factors was obtained. The salts used separated distinctly on two of the factors; the lithium and sodium salts on one, and the salts of the larger captions on the other. Sucrose, HCI and quinine‐hydrochloride correlate heavily with one and only one of the three remaining factors. These five main factors account for 92.6 % of the variance in the material. The conclusion may be drawn that an across‐fibre pattern contains taste modulicon sistent with the established concept of taste primaries, the primary referred to as salty, however, seems to consist of two independent moduli.
On the Relation between the Chorda Tympani Nerve Response, Arterial Oxygen Tension and Blood Flow in the Tongue of the Rat
Authors: Hellekant Göran 
Published: December 2008

AbstractThe summated chorda tympani respotise of the rat to taste stimtilation was recorded while, (a) the rat was artificially ventilated with hypoxic mixtures of oxygen‐nitrogen, (b) the blood flow through the ipsilateral coninion carotid artery and the intra arterinal tension were measured and (c) the tongue was pelfusrd with blood from one femoral artery The technique applied in (a) indicated that the animal was able to maintain its taste sensitivity until circulation collapsed. the methods of (b) showed tliat a decrease of taste response could be recorded even if the blood oxygen tension rose when the blood flow to the tongue dimmished. The results of (c) demonstrated that the taste response could be increasrd, maintained and decreased by changes of the blood flow to the tongue.
Antagonism of Slow Reacting Substance by Polyphloretin Phosphate on Isolated Human Bronchi
Authors: Mathé A. A. , Strandberg K. 
Published: December 2008

AbstractPurified slow reacting substance (SRS) induced a marked and long lasting constriction of isolated human bronchi. No signs of tachyphylaxis in the response to SRS were observed. Blockade of adrenergic, cholinergic, histaminergic and 5–hydroxytryptaminergir receptors did not effect the bronchoconstricting action of SRS. Adrenaline, theophylline and dibutyryl cyclic AMP counteracted the bronchoconstriction induced by SRS. Polyphloretin phosphate (PPP) antagonized the action of SRS, both on isolated human bronchi and on isolated guinea‐pig ileum. Antagonism by PPP could be surmounted by higher doses of agonist, and there was a parallel shift of the dose response curves of the agonist indicating a cormpetitive antagonism. PPP did not modify the bronchoconstriction induced by acetylcholine and histamine.
Postnatal Excitability Changes of the Ankle Monosynaptic Reflexes in the Cat
Authors: Mellström Anders 
Published: December 2008

AbstractThe effects of repetitive stimulation on the amplitude of ankle extensor and flexor mono synaptic reflexes were studied under various experimental conditions in high spinal cats during postnatal development. The extensor monosynaptic reflex elicited from a dorsal root at 1/9 sec decreases initially when the stimulus rate is increased to 2/sec. This depression increases with age and is more pronounced in the flexor monosynaptic pathway than in the extensor one in the newborn kitten. This latter observation and the demonstration of a subliminal fringe in the flexor motoneurone pool of the newborn kitten indicate an earlier maturation of the flexor monosynaptic pathway. In young kittens the extensor monosynaptic reflex decreases less with increasing rate of stimulation when elicited from a dorsal root than from a peripheral nerve. In older kittens the reverse is true. Prolonged stimulation reduces the differences between dorsal root and peripheral nerve stimulation. In young kittens prolonged dorsal root stimulation at 2/sec causes a decrease of the extensor monosynaptic response. In adult animals on the other hand it increases. The flexors show a passing increase and subsequent decrease in young kittens during prolonged stimulation and in the adult there is only a decrease. Nembuta® depresses the extensor monosynaptic potential and accentuates frequency‐dependent depression variably with age.
Recurrent and Antidromic Effects on the Monosynaptic Reflex during Postnatal Development in the Cat
Authors: Mellström Anders 
Published: December 2008

AbstractThe recurrent effects on the amplitude of the ankle extensor and flexor monosynaptic reflexes were studied at different rates of stimulation during postnatal development in high spinal cats. The recurrent + antidromic effects on the ankle extensor monosynaptic reflex were also in vestigated. Recurrent inhibition of extensors was observed in the youngest kittens but disappeared more or less during the first postnatal month to reappear during the first part of the Second month. At that time, recurrent inhibition of flexors also appeared as did recurrent facilitation. All recurrent effects were found to increase with stimulation frequency and, with the exception of the extensors during the first month, they also increased in both magnitude and duration with age, reaching adult values during the second postnatal month. It was concluded that the increased recurrent effects are partly due to a reduction of the excitability in the monosynaptic pathway, although a postnatal change in the recurrent effects per se can not be excluded. Recurrent + antidromic effects on the extensors were also found to increase in magnitude and duration with increasing age.
Electrolyte Distribution and Renal Function in the Hibernating Hedgehog
Authors: Clausen Gunnar , Storesund Asbjörn 
Published: December 2008

AbstractThe concentrations of Na, K, Mg and CI were determined in muscles and liver, various zones of the kidney, plasma, red blood cells, and bladder urine in active and hibernating hedgehogs. Freezing point depression and urea concentration were determined in the kidney, plasma and urine. Unaltered tissue water concentration and 15 to 20 per cent decreased CI and Na space suggest a shift of water from the interstitium to the cells during hibernation. Hibernation tended to alter the partition of electrolytes, between tissues and plasma, similarly to in vitro cooling of mammalian tissues. The bladder urine to plasma ratios of solute concentrations during hibernation, were: Na = 0.18, CI = 0.11, K = 6.4, Mg = 3.7, urea = 28, osmolarity = 3.4. Thus the extracellular ions Na and CI are conserved relative to the intracellular ions during the hibernating season. The osmolarity and the concentrations of urea, Na and CI did not increase from cortex to papilla in the kidneys of hibernating hedgehogs. Since the renal counter current mulitiplier system therefore is practically inoperative, the hyperosmotic bladder urine (1.1 Osm/l) sampled during hibernation must be produced during the intermittent arousal periods and not during hibernation.
Specificity of Sensory Messages Mediated through Chorda Tympani Fibres with Multiple Sensitivity to Gustatory and Thermal Stimuli
Authors: Andersen H. T. , Hartmann Å. O. 
Published: December 2008

AbstractSensory messages about taste and temperature transmitted through single chorda tympani fibres have been studied by means of factor analysis using the varimax criterion for factor rotation. Our analysis indicate that all sensory qualities studied, i.e. varm, cold, salty, sour, sweet and bitter are conveyed to the brain as separate sensory modalities. No groups of interacting stimuli could be identified at the level of the primary afferent neuron. It seems particularly important that the pattern of neural activity elicited by gustatory qualities may change over time so that the dynamic properties of the transmission system emerges as a possible mechanism of sensory discrimination. Moreover, this time dependent shift in the input of information to the central nervous system may give a clue to the phenomenon of aftertaste.
The Effect of Glucagon on Intestinal Motility and Blood Flow
Authors: Fasth S. , Hultén L. 
Published: December 2008

AbstractThe mechanism by which glucagon inhibits intestinal and vascular smooth muscle tone was studied in anesthetized cats. The intestinal motility was recorded by a volume recording device and the intestinal blood flow by connecting the left carotid artery via a drop recording unit with the superior mesenteric artery by a wide bore polyethylene tube. A femoral artery was used for recording of arterial pressure. Glucagon was administrated close intraarterially at different rates. In animals where the adrenals were left intact glucagoninfusion was followed by a considerable and immediate increase of intestinal blood flow and a somewhat delayed motility inhibition and blood pressure increase. When the adrenals were excluded glucagon still induced a blood flow increase. The motility inhibition and the blood pressure increase were both abolished, however. It is therefore suggested that glucagon exerts its action on the splanchnic area in two different ways, on the one hand by a direct effect on the vascular smooth muscles on the other hand by a release of catecholamines from the adrenal medullae which, in turn, inhibits intestinal smooth muscles.
Unidirectional Fluxes in Isolated Splenic Nerve Vesicles Measured by a Millipore Filter Technique:
Authors: Klein Richard L. , Lagercrantz Hugo 
Published: December 2008

AbstractIsotopically labelled noradrenaline (NA) exchange was determined in an improved preparation of NA storage vesicles isolated from bovine splenic nerve trunk. A Millipore filter technique was used which permitted analyses of unidirectional fluxes. In a Mg‐ATP supplemented medium at 30 and 20° C, vesicle NA is completely exchangeable with 0.5 to 3.0 μg l‐NA/ml in the medium. The kinetics are compatible with a single exponential component of exchange, and the data suggest a fully saturated Mg‐ATP complexing under these conditions.Reserpine in a concentration range between 2 × 10‐8 and 2 × 10‐7 M causes more pronounced inhibition of the transfer coefficient for NA influx than for efflux. However, no net loss of vesicle NA occurs because the drug inactivates a proportional amount of the readily exchangeable NA pool. Within the concentration ranges of NA and reserpine tested, virtually complete inhibition of NA exchange can be achieved and reversal of this inhibition by elevating the NA concentration in the medium can be demonstrated. The data is consistent with the suggestion that reserpine acts via transport sites in the vesicle membrane, rather than on the intravesicular NA complex per se.This membrane stabilizing concentration range of reserpine causes no obvious deleterious effects on the vesicles at the electron microscopic level.
Efferent Impulses in the Chorda Tympani Nerve of the Rat
Authors: Hellekant Göran 
Published: December 2008

AbstractEfferent impulses in the chorda tympani nerve of the rat could be recorded under neuroleptic analgesia but not under barbiturate anesthesia. The number of impulses recorded from the whole nerve ranged from 10 to about 120 imp/s. Recordings from branches of the combined chorda‐lingual nerve suggest that most of the observed activity was directed to structures inside the tongue.
The Disappearance of Acetylsalicylic Acid (ASA) in Aqueous Solution from the Cat Stomach and its Influence on the Transmucosal Ion Transport in the Innervated Non‐secreting Stomach
Authors: Frenning Bertil 
Published: December 2008

AbstractDuring instillation of aqueous solutions of acetylsalicylic acid (ASA) into innervated, non‐secreting whole stomach pouches in the cat, parallel decreases in the salicylate and hydrogen ion concentrations took place. There was a decrease in volume by an average of 20–25%. Secretion did not affect the absorption of ASA. To study the effect of ASA in aqueous solution on the ionic permeability of the gastric mucosa, HC1 was instilled before and repeatedly after an instillation of ASA. The gastric mucosal permeability for ions was increased after an instillation of ASA. A study of the changes in electrolyte concentration in the instilled HC1 solutions showed that a significant effect on the decreases in hydrogen and chloride ion concentration persisted 90 and 60 min respectively after an ASA instillation. The net effluxes of hydrogen and chloride ions and the net influx of sodium ions were, however, significantly increased only during 30 min. After an instillation of ASA a 2‐fold increase in the pepsin output was obtained during instillations of HC1. In no case was hemorrhage observed during instillation of ASA, and only in 1 expt. during the immediately following instillation of HC1. In all but 1 expts. hemorrhages occurred during the subsequent HC1 instillations. It is suggested that the permeability‐increasing effect of ASA is due to loosening of the mucosa with a consequent increase of the extracellular space.
Effects of Pilocarpine on L‐Dopa Turnover in the Exocrine Rat Pancreas
Authors: Alm P. 
Published: December 2008

AbstractThe turnover of L‐DOPA was microscopically and chemically studied in rats after pretreatment with pilocarpine alone or in combination with nialamide. Whenever pilocarpine was given, there was an almost complete extrusion of fluorescent (i.e.dopamine containing) zymogen granules from the exocrine cells. In such cases, specific fluorescence frequently appeared in the acinar duct lumina and the secretory duct system. Compared with animals given L‐DOPA, pretreatment with pilocarpine resulted in higher initial concentrations of DOPA but unchanged levels of DA. These were then eliminated faster than in non‐pilocarpine pretreated animals. In animals pretreated with pilocarpine and nialamide the DA elimination was faster than in animals pretreated with only pilocarpine. The result of the present work indicate that the L‐DOPA turnover is influenced by changes in the pancreatic secretory activity.
Studies on Tetrodotoxin Resistant Action Potentials in Denervated Skeletal Muscle
Authors: Harris J. B. , Thesleff S. 
Published: December 2008

AbstractIn this study it is shown that action potential generation in rat, mouse and cat muscles is blocked by tetrodotoxin (TTX, 10‐6M) but that the chronically denervated muscles of these species are partially resistant to TTX. In denervated rat muscles the development of the TTX resistant action potential during the first four days of denervation is paralleled by the spread of extrajunctional cholinergic sensitivity. However, the extrajunctional cholinergic receptor and the TTX resistant action potential can be selectively blocked by drugs, indicating that the action potential site and the cholinergic receptor are not identical structures. Denervated muscles are also partially resistant to saxitoxin, although less so than to TTX.
A Standardized Technique for Drainage and Collection of Cardiac Lymph
Authors: Kluge Trond , Ullal Shiv R. 
Published: December 2008

AbstractA standardized method for cannulation of cardiac lymphatics and drainage of cardiac lymph in dogs is presented. The technique comprises visualization of lymph vessels by myocardial injection of T 1824 dye and cannulation of an afferent lymphatic to the cardiac lymph node. A stable drainage is ensured by traction and countertraction on sutures adjacent to the cannula. Sucessful collection of lymph has been obtained in about 85 per cent of the experiments, and for periods lasting more than 6 h. The method may prove a useful tool for further investigations in cardiac physiology.
The Action of Progesterone on the Sodium Transport of Isolated Frog Skin
Authors: Tomlinson R. W. S. 
Published: December 2008

AbstractIt has been shown that progesterone at concentrations greater than 10‐5 M in the medium bathing the outside surface of the isolated frog skin causes an inhibition of the short‐circuit current within a few minutes. The inhibition is due to a decreased influx of sodium with no effect on sodium efflux or chloride influx. The inhibition is readily elicited when the progesterone is added to the outside bathing medium as opposed to the inside bathing medium although progresterone transfer across the skin is the same in both directions. The adenosine triphosphate concentration of the progesterone treated skins was not significantly different from the controls. It is suggested that progesterone interacts with the lipid moeity of an outward‐facing membrane preventing sodium influx.