bluuebunny/crossref_metadata_2025_split huggingface dataset:
EEG Synchronization and Sleep Induced by Stimulation of the Medial and Orbital Frontal Cortex in Gat
Authors: Alnæs E. , Kaada B. R. , Wester K. 
Published: December 2008

AbstractElectrocortial synchronization, associated behaviourally with light sleep, was induced by low‐frequency stimulation of the subcallosal region and the orbital gyrus of the frontal lobe in unanesthetized cats. The effect was weaker than that obtained with basal forebrain stimulation. The above cortical areas have previously been shown to exert strong inhibitory influences on a variety of somatomotor and autonomic activities. High‐frequency stimulation of the same areas produces electrocortical desynchronization and behavioural arousal. It is suggested that the subcallosal and orbital portions of the frontal cortex give origin to.a descending system capable of modulating the excitatory state of sleep‐producing mechanisms in the brain stem or diencephalon.
Metabolism of Fracture Callus of Rat in vitro: I. Oxygen Consumption and Lactic Acid Production
Authors: Penttinen R. 
Published: December 2008

AbstractCompared with the rat bone the oxygen uptake by the slices of callus is low during the proliferation of the cartilage in the callus and even lower during the active ossification. The production of lactate by the slices is equal to that of rat bone. These two parameters of the energy metabolism, expressed per whole callus, are maximal on the 9th day after the fracture, corresponding to the degeneration and calcification of the cartilage. Calculated on the weight basis, both parameters decline during the healing. The transition from cartilaginous to ossifying callus is characterized by a drop in the ratio of lactate produced to oxygen consumed. It is concluded that the energy metabolism in regenerating bone is mainly anaerobic thus resembling the granulation tissue.
Transcapillary Transport of D‐and L‐Glucose in Isolated Skeletal Muscle
Authors: Crone C. 
Published: December 2008

AbstractThe study was performed to clarify whether D‐glucose traverses muscle capillary walls faster than L‐glucose. The transcapillary transport of D‐glucose was slightly faster than that of L‐glucose in experiments at 37° C. The difference in transport rate persisted when the experiments were carried out at 4° C. This indicates that the faster transport of D‐glucose is not due to facilitated transport involving enzymatic steps. It is proposed that the ground matrix of the interendothelial cleft (and of the extravascular space) gives the D‐form of glucose a slight diffusional advantage over the L‐form. A pore effect cannot be completely ruled out.
An Attempt to Explain Nervous Transmitter Release as due to Nerve Impulse‐Induced Cation Exchange
Authors: Uvnäs Börje 
Published: December 2008

AbstractAn attempt is made to explain the storage and release of transmitters—particularly in the functional pool—at adrenergic and cholinergic nerve terminals as due to a cation exchange between amines bound to a sulphomucopolysaccharide‐protein complex in transmitter‐containing structures and inorganic ions in the neuro‐effector junctional gap. It is proposed that the exchange occurs at the nerve terminal membrane‐vesicle contact area during the period of nerve impulse‐induced depolarization and increased cation permeability (Fig. 2). The theory allows for a total or fractional release of the granule amine stores with or without a concomitant expulsion of the granule matrix. Such phenomena as reuptake, release by miniature end potentials, by amines and by drugs, fatigue etc. might also be explained on an ion exchange basis.
Circulatory Control via Vagal Afferents: III. Control of arterial blood pressure by afferents via the laryngeal communicans with special regard to the restitution after hemorrhage
Authors: Castenfors Jan , Knutsson Evert , Sjöstrand Torgny 
Published: December 2008

AbstractThe effect of afferent discharges via the laryngeal communicans on the control of the blood pressure has been studied in selected Sprague‐Dawley rats by cutting the inferior or/and superior laryngeal nerves at varying blood volumes. The subsequent changes can be divided into three phases: a brief excitatory phase, an intermediate and a late phase. The intermediate phase is characterized by an increase of heart rate and blood pressure, especially marked after hemorrhage. The late phase appears after a latency of about 20 min, is fully developed in one hour or more and consists, at ordinary or decreased blood volume, in a lowering and unbalance of the blood pressure. If the laryngeal pathway is excluded before or briefly after a blood loss of 30–40 % of the blood volume, the pressure is first restored to about 80 % of the initial level but then drops successively until the death of the animal in circulatory insufficiency. The effect of laryngeal deafferentation has been compared to the acute effect of hypophysectomia. The similarity of the delayed pressure regression at ordinary and decreased blood volume indicates that the laryngeal nerves act as a pathway for the stimulation of release of ADH vasopressin from the low pressure side.
Circulatory Control via Vagal Afferents: IV. Integration of the central control mechanisms in the circulatory‐adaptation to variations of blood volume
Authors: Castenfors Jan , Sjöstrand Torgny 
Published: December 2008

AbstractThe interrelations of receptor mechanisms localized to the central part of the cardiovascular system have been studied by alternative exclusion of afferent discharges via the laryngeal pathway, vagus trunk and sinus nerve in Sprague‐Dawley rats. An initial increase of arterial pressure followed by a lasting decrease, usually coincident with the appearance of pressure waves, was found in most animals on laryngeal deafferentation but in others on vagotomy. A preceding or subsequent exclusion of afferents via, respectively, the vagus trunk and laryngeal nerves exerted no or only small effects. The pressure response to occlusion of the common carotid arteries was decreased after blood infusions, also after hemorrhage to 60 mm Hg. On a further blood loss to a level of 25 mm Hg the response increased. Occlusion exclusively of the internal carotids provoked practically the same effect under these conditions. On laryngeal deafferentation and vagotomy, respectively, the pressure response increased. Deafferentation after blood infusion, especially combined with carotid occlusion and vagotomy, provoked forced respiration and in 3 of 6 animals signs of pulmonary edema, fatal in two. It was concluded that in hypervolemia the circulation is adapted wholly and in hypovolemia in part via afferents running in the laryngeal communicans and/or vagus trunk.
Degeneration Activity in the Rat Urinary Bladder
Authors: Elmér Mats 
Published: December 2008

AbstractPeriods of increased activity were found in the urinary bladder of the rat in situ 50–90 h after postganglionic parasympathetic denervation. The activity was not affected by hexamethoniuni, eserine produced an increase of the activity, and atropine and Hoechst 9980 totally abolished it. It is concluded that the activity is due to transmitter leaking from degenerating postganglionic nerve terminals and that the transmitter probably is acetylcholine.
Prostaglandins in Human Burn Blister Fluid
Authors: Arturson Gösta , Hamberg Mats , Jonsson Carl‐Evert 
Published: December 2008

AbstractAcidic lipids with smooth muscle stimulating activity were isolated from human burn blister fluid. Analysis by silicic acid chromatography and thin‐layer chromatography indicated the presence of prostaglandin E and F compounds. Prostaglandin E2(about 1.9 ng/ml of blister fluid) was identified and quantitatively determined by gas‐liquid chromatography—mass spectrometry. No metabolic conversion of tritium‐labelled prostaglandin E1incubated with blister fluid was observed.
On the Regional Metabolism of Beef Heart Ventricles
Authors: Tota B. 
Published: December 2008

AbstractThe concentrations of some oligoelements (iron, copper, zinc) and electrolytes (calcium, magnesium, potassium) and the activity of the succinate‐cytochrome c reductase system were determined in various regions of the ventricles of beef heart. In the subepicardial layers of the ventricles and in the upper part of the septum a higher content of iron and copper and a greater succinate‐cytochrome c reductase activity were observed. These findings were consistent with a decreasing oxidative metabolic gradient both from the epicardium to the endocardium in the free ventricular walls and from the upper to the lower part of the septum. A higher content of potassium was demonstrated in the subendocardium of the ventricles. Significant differences in the concentrations of zinc, magnesium and potassium were found between the right and left papillary muscles.
A Study of the Effects of Some Chemically Welldefined Lissamine Greens on Tubular and Overall Renal Function in the Rat (with an evaluation of the validity of lissamine green transit time measurements in studies of tubular function)
Authors: Elmer Mogens , Leyssac Paul P. 
Published: December 2008

AbstractChemically different Lissamine greens were investigated for their immediate and late effects on renal functional parameters. The data indicate (1) that there was no consistent change in transit times (TT) in series of up to four repeated single injections with different LG completed within 8 min. (2) proximal and distal intratubular pressure responded to a single i.v. injection of LG with two distinct pressure increments, similar for all dyes tested. The first increase (prox.: 1–3 mm Hg; dist.: 1–2 mm Hg) coincided with a blood pressure response; the second increase (prox.: 1–2 mm Hg; dist.: 0.5–1.5 mm Hg) started when LG appeared in distal convolutions. The changes in flow velocity resulting from such pressure changes would not cause any significant error in the measured TT. (3) the late effects of LG were an increase in overall reabsorption capacity (predominatly in the loop of Henle) a parallel increase in glomerular filtration rate, and an increase in urine flow and osmotic excretion rate. Proximal reabsorption rate was unaffected. No difference in response was observed between different LG. Neither GFR nor urine flow changed significantly in control experiments in which a similar osmotic activity of mannitol was injected. It is concluded that TT measurements with LG may provide valid information on tubular function; but the late effects of LG would limit its use to a single measurement at the end of an experiment.
Oxygen Uptake, Muscle High‐Energy Phosphates, and Lactate in Exercise under Acute Hypoxic Conditions in Man
Authors: Knuttgen Howard G. , Saltin Bengt 
Published: December 2008

AbstractThe relationships among muscle metabolite concentration, exercise intensity, and oxygen utilization were studied under simulated altitude conditions (decompression chamber, 462 mm Hg b.p.). 5 male subjects exercised in 4 min bouts on a cycle ergometer at a wide range of exercise intensities (range 20–114% altitude max Vo2). Oxygen uptake was determined throughout exercise and recovery. Muscle biopsies (vastus lateralis) and fingertip blood samples were taken at rest and during recovery. Muscle ATP and creatine phosphate concentrations became reduced during exercise at all intensities. Little or no increase in lactate was observed below apprpx. 60% altitude max Vo2. The hypoxic condition caused a decreased acceleration from resting Vo2 and an increase in O2‐deficit at each absolute intensity as compared with normoxia. Close relationships were observed between level of high‐energy phosphate depletion and both O2‐deficit and fast component of O2‐debt not different from the same relationships under normoxic conditions. Virtually all differences in physiological response to identical exercise intensities at altitude as compared to normoxia were appropriately adjusted by expressing exercise intensity relative to the respective aerobic power capacities in the two conditions. Physiological responses to this type of exercise appear determined in great part by the availability of oxygen.
A Two‐Phased Change in Dynamic Lung Compliance during Hemorrhagic Hypotension
Authors: Bø Gunnar , Hauge Anton 
Published: December 2008

AbstractProlonged hemorrhagic hypotension and multiple trauma not involving the lungs can, in patients, induce respiratory failure with a fall in lung compliance and a concomitant increase in the work of breathing (Moore et al. 1969). However, animals experiments have revealed conflicting results concerning the magnitude and direction of change in lung compliance after a hemorrhage. We have studied the effects of 3 hr of hypovolemic systemic hypotension (femoral a. pressure: 50 to 60 mm Hg) on lung mechanics in open chest cats ventilated by positive pressure.Mean dynamic lung compliance (CL) rose during the first 30 min post‐bleeding by 13 ± 5 per cent whereafter CL gradually fell to 26 ± 6 per cent below its initial value, in the third hr of observation. On the basis of our monitoring of vascular parameters and alveolar‐arterial PO2 differences we suggest that the early rise in CL is due to reduced pulmonary blood volume and vascular distending pressure, whereas the later fall in CL is caused by collapse and narrowing of peripheral airways. No signifiant changes in nonelastic (frictional) resistance could be detected during the 3 h observation period.
The Effects of Amytal and Inactin on Isosmotic Net Fluid Transport in the Rabbit Gall‐Bladder In Vitro
Authors: Christensen P. , ØStergaard Kristensen L. , Leyssac P. P. 
Published: December 2008

AbstractThe effects of the oxybarbiturate Amytal and the thiobarbiturate Inactin on isosmotic fluid absorption by the rabbit gall‐bladder in vitro sac‐preparation was studied. Both barbiturates inhibited net fluid transfer rate. The effect was dose‐dependent. Inactin was a more potent inhibitor than Amytal with effect from the serosal side at concentrations down to 1 × 10‐4M (i.e.below concentrations obtained in plasma of anesthetized rats); inhibition by Amytal unilaterally was not observed at concentrations below 1 × 10‐3M (a concentration above that of plasma of anesthetized rats). Amytal depressed oxygen consumption in parallel with net fluid transport rate, while Inactin was without any significant effect on oxygen consumption in spite of severe inhibition of net fluid transport rate. The inhibitory effect of Amytal applied bilaterally was reversible after exposure to the drug for more than 60 min. The effect of brief exposure (20 min) to Inactin bilaterally was reversible; after exposure for 60 min or more the effect was irreversible in recovery periods of up to 60 min duration. Both barbiturates accumulated in the gall‐bladder tissue with a concentration factor of about 1.5. After washing in barbiturate‐free Ringer solution (recovery periods) for 45–60 min, neither Amytal nor Inactin were detectable in the tissue. The sensitivity of the method allowed detection of 0.2 mM Inactin per kg wet weight,i.e.no more than 2% of the Inactin accumulated during the experimental period. The data suggested that the effects of the two barbiturates were additive.
Effects of Ionic Concentration on Permeability Properties of Nodal Membrane in Myelinated Nerve Fibres of Xenopus laevis. Potential Clamp Experiments
Authors: Brismar Tom 
Published: December 2008

AbstractThe specific sodium and potassium permeability mechanisms in the nodal membrane were analysed. The current to potential relations were measured with various external concentrations of NaC1, KC1 and CaC12. PNa and PK were calculated. The measurements showed that the permeability to potential curve was shifted along the potential axis and in the same direction for changes in the uni‐univalent salt concentration as well as for changes in [Ca]. The shift caused by changes in [Ca] was larger at low uni‐univalent salt concentrations and the shift caused by [K] and [Na] increased with decreased [Ca]. It was assumed that the membrane has negative charges fixed to its outside surface. The permeability shifts were approximately predicted by a charge density of‐5.5 μC μ cm‐2. A decrease in [Na], but not in [Ca] caused a decrease in PK. This behaviour was not predicted.
Muscle Metabolism and Enzyme Activities after Training in Boys 11–13 Years Old
Authors: Eriksson Bengt O. , Gollnick Philip D. , Saltin Bengt 
Published: December 2008

AbstractThe effect of training on the skeletal muscle metabolism of 11‐to 13‐year‐old boys was examined. In one experiment changes in blood lactate, and muscle lactate, CP, ATP, and glycogen were determined at rest and following exercise before and after 4 months of training. The concentrations of glycogen, CP and ATP at rest were higher (P<0.01) following training. Blood and muscle lactate were 23 and 56 % higher after maximal work following training. A greater reduction in muscle glycogen occurred during maximal work after training but the pattern for ATP and CP depletion was unchanged. In a second experiment boys trained by pedalling a bicycle ergometer an average of 30 min 3 times a week for 6 weeks. Biopsy samples of the vastus lateralis were examined for oxidative (succinate dehydrogenase) and anaerobic (phosphofructokinase) capacity before and after training. The fiber composition and relative oxidative capacity in the fibers was determined histochemically. Succinate dehydrogenase and phosphofructokinase activities increased 30 and 83 %, respectively, following training. Fiber distribution was unchanged by training but the oxidative capacity of both fiber types appeared to increase.
A Respiratory Reflex Elicited by Hemorrhage and Mediated by Vagal Afferents
Authors: Sjöstrand Torcny 
Published: December 2008

AbstractVentilation, heart rate and arterial pressure were recorded in rats on blood losses from 1 to 6 ml (6–36 % of blood volume). About 15 s after the onset of the blood drawing and the coincident decrease of arterial pressure, the tidal volume increased on a loss of 1–3 ml. This was regularly observed in 10 rats. On larger hemorrhages the tidal volume decreased. The respiratory rate decreased in some animals already at a blood loss of 1 ml, in others at losses above 2 ml. The increase of the tidal volume was totally inhibited in 5 rats by exclusion of afferents in the recurrent nerves by cold block or section. In three other rats the increase of the tidal volume was inhibited on cutting also of the right or both vagal nerves. The decrease of tidal volume and of respiratory frequency on large blood losses was not inhibited by vagotomy. It is presumed that the increase of the tidal volume on a small to moderate blood loss is provoked by a vagal reflex elicited by receptors on the low pressure side and that the decreased ventilation on larger hemorrhages is elicited from the respiratory centres by the change of the cerebral blood flow.
Intestinal Vascular Responses to 5‐Hydroxytryptamine
Authors: Biber Björn , Fara John , Lundgren Ove 
Published: December 2008

AbstractThe in vivo and in vitro effects or 5‐hydroxytryptamine (5‐HT) were investigated on the mesenteric vasculature of the cat. Close i.a. injections (10 μg) or infusions (10–15 μg/min) into the superior mesenteric artery of chloralose anesthetized cats generally induced an intestinal vasodilatation of 60–150 % above control which was unaltered by α‐or β‐adrenergic or cholinergic receptor blockade, and which after its development was unaffected by intestinal motility responses. Following nerve blockade by tetrodotoxin, the vasodilator response to 5‐HT was changed to vasoconstriction. During 5‐HT infusions of 20–50 μg/min intestinal blood flow and intestinal capillary filtration coefficient (CFG), measured plethysmographical‐ly, increased significantly above control, while at infusions of 10–15 μg/min 5‐HT increased CFC without increasing intestinal blood flow. In in vitro studies on strips or segments of mesenteric arteries and veins from the cat and rat, 5‐HT constantly increased isometric tension in all vessels studied. The response was unaltered by adrenergic or cholinergic receptor blockade and was not related to passive tension applied to the vessels nor to the presence or absence of noradrenaline in the bath. The divergent in vivo and in vitro response are discussed in terms of the following possible mechanisms: 1. A differential effect of 5‐HT with constriction of large vessels and dilatations of smaller ones; 2. A direct constrictor effect on the vascular smooth muscle via specific serotonic receptors, as well as an indirect dilator effect, perhaps mediated through local nervous pathways.
Metabolism of14C‐Histamine in Goats and Pigs Treated with Aminoguanidine
Authors: Eliassen Knut Arnet 
Published: December 2008

AbstractThe effect of aminoguanidine, an inhibitor of diamine oxidase (E.C. 1.4.3.6.) on the catabolism of14C‐histamine has been studied in goats, a species in which oxidative deamination dominates, and pigs, a species in which methylation is the most important route of inactivation. In aminoguanidine treated goats the total14C‐imidazoleacetic acid (14C‐ImAA) in urine was reduced from about 70% to about 4% and in pigs from 18% to 2%. In goats the decrease in the formation of14C‐ImAA was partly compensated by an increased methylation though the fraction of14C‐histamine excreted unchanged was increased tenfold in the last‐mentioned species. In pigs the decrease in14C‐ImAA seemed to be fully compensated by increased methylation of histamine. The decrease in the excretion of non‐radioactive 1.4‐MeImAA in pigs and the change in the ratio:14C‐1.4‐MeImAA/14C‐1.4‐MeHi in both pigs and goats during aminoguanidine treatment indicated that oxidation of 1.4‐MeHi to 1.4‐MeImAA is partly catalyzed by enzymes sensitive to aminoguanidine. The incomplete inhibition of the14C‐ImAA formation during aminoguanidine treatment indicates that enzymes other than diamine oxidase might participate in the oxidation of histamine to ImAA.
Lateral Line Input to the Crista Cerebellaris in the Eel. Field Potentials and Histology
Authors: Alnæs Egil 
Published: December 2008

AbstractThe central nervous effects of electrical stimulation of the Nn. lat. posteriores have been investigated. Maximal field potential amplitudes were found in the medial part of the ipsilateral crista cerebellaris. The field potential evoked from stimulation of fast conducting nerve fibres consisted of an afferent pre‐synaptic volley and a post‐synaptic complex wave. The latter is shown to consist of a population EPSP and a population spike in subcristal neurones. Excitatory activity from the contralateral nerve impinges on the same neurones, and bilateral summation occurs. The contralateral field potential reverses more superficially than does the ipsilateral field. Post‐excitatory reduction of population spike can be explained by refractoriness. The crista region was investigated with conventional light and electron microscopical methods. Myelinated primary afferent axons from the R. lat post. N. X. terminate in the subcristal region on the ipsilateral side. Subcristal cells have dendritic ramifications in the molecular layer. Unmyelinated axons in this layer partly consist of lateral line primary afferents. These axons differ from the cerebellar parallel fibres by their extensive branching and irregular directional architecture. Fusiform swellings of these axons establish abundant isomorphous synapses with dendritic spines. The distribution of field potential negativity in depth corresponds to the distribution of subcristal neurones.