bluuebunny/crossref_metadata_2025_split huggingface dataset:
Interference of Light on the Determination of Low Glucose Concentrations with Glucose Oxidase
Authors: ÅBerg Bo 
Published: December 2008

AbstractA method for measuring glucose concentrations down to 10 μM/L is described. This is a modification of a method based on a commercially available glucose‐oxidase reagent. Some factors which are important for good reproducibility were investigated. Most important is the light sensitivity of the chromogenic reaction. The absorbance decrease which results from illumination is, however, reversible in the dark. If the samples are kept in darkness until the absorbance is measured and a suitable photometer is used, the method has a good reproducibility and is simple to perform.
A Possible Role Played by Central Monoamine neurones in Thermo‐Regulation
Authors: Corrodi Hans , Fuxe Kjell , Hökfelt Tomas 
Published: December 2008

AbstractThe effect of a cold and warm environment on the activity of the central catecholamine (CA) and 5‐hydroxytryptamine (5‐HT) neurones has been studied with the help of a combined biochemical and histochemical approach using inhibitors of the tyrosine and tryptophane hydroxylase. The central noradrenaline (NA) and 5‐HT neurones of rats kept at: 40d̀ C were found to increase their state of neuronal activity. whereas the 5‐HT but not the CA neurones of rats kept at ± 3d̀ C showed a decreased neuronal activity. These results indicate that the central NA and 5‐HT neurones participate in thermo‐regualtion.
Effects of Acetylcholine and Biogenic Amines on Pulmonary Smooth Muscle in the African Lungfish, Protopterus Aethiopicus
Authors: Johansen Kjell , Reite Ola B. 
Published: December 2008

AbstractSmooth muscles from the glottis sphineter and pulmonary parenchyma were excised from freshly killed specimens of the African lungfish,Protopterus aethiopicus, and mounted in a bath of Ringer solution while responses to pharmacological agents were studied. Both muscle preparations gave qualitatively similar responses. Acetylcholine caused contraction which was abolished by pretreatment with atropine. Histamine and serotonin also contracted the muscles, their effects being diminshed by mepyramine and methysergide. Adrenaline and noradrenaline relaxed the muscle preparations. Neither regitine nor propranolol affected this response. Isoproterenol had a slight relaxing effect. Anoxia and hypercapnia did not influence the contractile state of the muscles.
Studies on the Time Course of Histamine Release and Morphological Changes Induced by Histamine Liberators in Rat Peritoneal Mast Cells
Authors: Bloom Gunnar D. , Fredholm Bo , Haegermark ÖSten 
Published: December 2008

AbstractThe histamine release process in rat peritoneal mast cells, exposed to histomine liberators, can be terminated by the addition of ice‐cold salt solution. This was taken advantages of for studies on the time course of histamine release and concomitant morphological changes induced by compound 48/80, bee venom and n‐decylamine. After addition of compound 48/80 or bee venom, histamine was released in about 10 sec at 37/dG C and about 30 sec at 22/dG C. independently of the liberator concentration. AT 22/dG C the release was preceded by a lag period, which was shorter with higher liberator concentrations. The enzyme inhibitors potssium cyanide and N‐ethylmaleimide did not alter the duration of the reaction induced by compound 48/80 or bee venom, although they lowered the final release. The release curve showed a different shape when histamine was released by n‐decylamine. The morphological changes, studied both in the light and electron microscope, were found to be correlated to the histamine release.
Histamine Release from Isolated Rat Peritoneal Mast Cells Induced by Adenosine‐5‘‐Triphosphate
Authors: Diamint Bertil , Krüger Per Göran 
Published: December 2008

AbstractHistamine release from isloated rat mast cell is induced by ATP (10‐5— 3 × 10‐5M). The activity found in an ADP‐perepatation was shown to be due to contamination with ATP, purified ADP has no activity. AMP, 3′ 5′ AMP, PCr and PEP were without histamine releasing activity. Histamine release induced by ATP was compared with that caused by compound 48/80 with respect to the influence of Ca++, Mg++, Zn++, ouabain, DNP, oligomaycin and glucose. The results are interpreted to indicate that ATP and compoundf 48/80 release histamine by mechanisms that in certain respects differ from each other. The histamine releasing effect of ATP is discussed in relation to the enery‐requiring mechanism that iis known to be involved in histamine release by compound 48/80.
Degranulation and Histamine Release, Two Consecutive Steps in the Response of Rat Mast Cells to Compound 48/80
Authors: Thon I. L. , Uvnäs B. 
Published: December 2008

AbstractIsolated rat peritoneal mast cells were exposed to compound 48/80 in A isotonic salt solution and in B isotonic sucrose solution. In both cases degranulation and histamine release occurred. In A all the released histamine appeared dissolved in the suspension medium, the discharged granules having lost their histamine. In B the discharged granules were show to retain histamine. These granules released their histamine when suspended in a NaC1‐containing medium. Depleted granules could be refilled with histamine by suspension in a histamine‐containing medium and again depleted of the amine by exposure to sodium chloride. The proposal is made that the histamine release induced by compound 40/80 is a two stage process, a primary energy‐requiring transport of histamine‐containing granules to the outside of the mast cell and a secondary nonenergy‐requiring physico‐chemical process, an extracellular cation exchange in the shed granules between histamine and cations, mainly sodium in the tissue fluid.
Gastric and Duodenal Ulcers in Cats Following Reserpine
Authors: Emås Sverre , Fyrö Bengt 
Published: December 2008

AbstractThe incidence of gastric and duodenal ulcers following reserpine was studied in cats. A single injection of 0.10 mg/kg of reserpine produced the highest incidence of antral ulcers (89 per cent) after 12 hrs and of duodenal ulcers (50 per cent) after 24 hrs. No ulcer was detected 8 days or more after the single injection. Reserpine injected every 24 hr for 2 to 4 days produced a lower incidence of antral ulcers than a single injection. In cats injected daily with reserpine for 6 days or more no ulcer was detected. Reserpine produced no ulcer in the oxyntic gland area. The ulcerogenic effect of reserpine remained after adrenalectomy. Truncal vagotomy or pretreatment with reserpine reduced the incidence of ulcers and also the acid response to reserpine. 0.10 mg/kg of reserpine was more effective to produce ulcer and to stimulate acid secretion than 0.03 mg/kg/. The results suggested that the transient ulcerorgenic effect of reserpine was related to its effect on acid secretion.
A Micromethod for the Determination of Choline Acetylase in Individual Cells
Authors: Buckley G. , Consolo S. , Giacobini E. , McCaman R. 
Published: December 2008

AbstractA micromethod is described for the determination of choline acetylase in single cells. The method involves the use of [14C] acetyl CoA adn choline as suvstrates giving rise to [14C] acetylcholine which is quantitatively precipitated as a reineckate. After washing the reineckate to remove the residual radioactivity of the substrate, the labelled reineckate is dissolved in acetone and counted in a scintillation counter. The method is suitable for the quantitative determination of enzyme activities in 50–100 individual cells per experiment. The sensitivity of the method is 10‐13 moles of [14C] acetylcholine/hour.
Intracellular Variations of Na and K in Isolated Nerve Cells
Authors: Giacobini Ezio , Hovmark Stefan , Kometiani Zurab 
Published: December 2008

AbstractThe variations of intracellular Na and K content in isolated crustacean sensory neurons were examined in different experimental conditions with the help of a sensitive microflamephotometric technique. In the experiments with physiological solution, after the isolation of the sensory neuron, the ionic events can be divided into two periods. During the first period, the initial period, a continuous recovery from the initial distortion of the ionic contents is going on. The intracellular cationic content is influenced during this period by at least two processes acting simultaneously and counteracting each other; one depending on the manipulation of the cell, the other on the active transport. If the active transport mechanism is inhibited, (e.g.under the effect of ouabain or in K free or Na free medium) the recovery does not take place. The second period starts about 1 hr later and is characterized by stationary levels of Na and K which—in Van Harreveld's solution—are close to physiological levels. This period may continue during at least 5 hrs. Tetrodotoxin (0.0167 μg/m1) glucose (1 mM) and shortlasting physiological stimulation (about 30,000 impulses) do not significantly change the intracellular Na or K.
Thermoregulatory Responses to Arm Work, Leg Work and Intermittent Leg Work
Authors: Nielsen Bodil 
Published: December 2008

AbstractNielsen, B. Thermoregulatory responses to arm work, leg work and intermittent leg work. Acta physiol. scand. 1968. 72. 25–32.The increase in esophageal temperature during continuous work on a bicycle ergometer with the arms and with the legs was compared. Also the effect of intermittent leg work (30 sec rest/work intervals) was compared to that of continuous work. At the same rate of metabolic energy production the esophageal temperature in the steady state was about the same independent of the different degree of anaerobicity and the different neuromuscular factors. It is therefore suggested that chemical factors liberated in proportion to the aerobic prosesses is responsible for the temperature setting during work. The sweat rate and the skin circulation expressed as conductance of the peripheral tissues carried in proportion to the total heat production independent of neuromuscular factors.
On the Location of the Line of Gravity in Relation to L5 in Standing
Authors: Klausen Klaus , Rasmussen Birger 
Published: December 2008

AbstractKlausen, K. and B. Rasmussen. On the location of the line of gravity in relation to L5 in standing. Acta physiol. scand. 1968. 72. 45–52.The determination of the location of the horizontal axis in the frontal plane for movements in the sagittal plane between L4 and L5 is based on the observation that the erectores spinae muscles and the rectus abdominis muscles in the upright standing position are acting as antagonists and antigravity muscles. X‐ray pictures were taken in the sagittal plane with the subjects standing a) with slight activity in the erector spinae muscles and b) with slight activity in the rectus abdominis muscles. The location of the line of gravity for the parts of the body above the level of L5 was then determined with the subjects standing in the same positions. These determinations revealed that the activity in the erector spinae muscles ceases and is replaced by activity in the rectus abdominis muscles, when thv line of gravity passes a point about 3 cm dorsally to the center of the inter‐vertebrate disc between L4 and L5. Similarly the location of the line of gravity in the frontal plane was determined in relation to L5. The results are discussed in view of previous findings.
Function of Cholinergic Nerve Fibres in the Cat Iris Dilator
Authors: Ehinger B. , Falck B. , Persson H. 
Published: December 2008

AbstractEhinger, B., B. Falckand H. Persson.Function of cholinergic nerve fibres in the cat iris dilator. Acta physiol. scand. 1968.72. 139–147.The effect of electrical stimulation, noradrenaline, acetylcholine, isoprenaline, tyramine, phenoxybenzamine, dibenamine, atropine, and INPEA was investigated in normal, sympathetically and parasympathetically denervated dilator muscles. High‐frequency stimulation caused the muscle to contract and low‐frequency stimulation caused it to relax. The response to high‐frequency stimulation was blocked by phenoxybenzamine, dibenamine and sympa‐thectomy, while the response to low‐frequency stimulation was blocked by atropine and para‐sympathectomy. Acetylcholine gave an initial relaxation followed by a slow contraction. The latter was blocked by phenoxybenzamine. After sympathetic denervation, acetylcholine in moderate doses elicited relaxations only. Atropine in moderate concentrations depressed the response to noradrenaline and to high‐frequency stimulation. At lower doses, the effect was reversed: atropine potentiated the response to noradrenaline and high‐frequency stimulation. This potentiation was abolished by parasympathectomy. It is concluded that the dilator pupillae is innervated by both adrenergic and cholinergic fibres, and an interaction between the two fibre types is not excluded.
Nervous Control of Urinary Bladder in Cats: I. The collecting phase
Authors: Edvardsen Per 
Published: December 2008

AbstractEdvardsen, P. Nervous control of urinary bladder in cats. I. The collecting phase. Acta physiol. scand. 1968. 72. 157–171.Intravesical pressure under isometric conditions was studied in anesthetized cats after operative canalization of the bladder. Records were obtained after selective transection at the peripheral and at the intraspinal level of the sympathetic and parasympathetic nerves supplying the bladder, after rhizotomy of the thoraco‐lumbar and sacral nerves to the bladder, and after transection of the spinal cord at various levels. With small bladder volumes no change in pressure was observed after the various lesions, but as the volume increased, the concomitant rise in bladder pressure was progressively inhibited by sympathetic nervous impulses. In particular was this inhibition marked during the last one‐third of the cystometrogram. The sympathetic influefice is maintained by a spinal ieflex with the afferent path through the posterior sacral roots, its stimulus being stretching of the bladder wall. The effect of this spinal adaptation reflex is thus to permit increasing bladder volumes with only moderate increases in bladder pressure. ‘Nonspecific’ bladder responses consisted in an increase in motility caused by the laparotomy, and an inhibition of motility caused by any intraspinal procedure. This inhibitory effect was found to be due to discharge through the sympathetic nerves on manipulation of spinal structures, regardless of their relation to the segments supplying the bladder.
Nervous Control of Urinary Bladder in Cats: III. Effects of autonomic blocking agents in the intact animal
Authors: Edvardsen Per 
Published: December 2008

AbstractEdvardsen, P.Nervous control of urinary bladder in cats. III. Effects of autonomic blocking agents in the intact animal. Acta physiol. scand. 1968.72. 183–193.Bladder motility in anesthetized or decerehrated cats was recorded under isometric conditions before and after the administration of graded doses of various agents with peripheral or ganglionic blocking effects on the autonomic nervous system. Direct or indirect cystometry was employed when the effects on the collecting or on the expulsion phase, respectively, were studied.Atropine, which blocks at cholinergic receptor sites, made the micturition contraction inefficient as the ability of the bladder to sustain the initial contraction was abolished.Hexamethonium, which blocks ganglionic transmission, impaired the spontaneous micturition contraction as well:by also preventing, the initial pressure rise from occurring. The drug blocked the sympathetic ganglia at doses smaller than those which blocked the parasympathetic ones. The effects ofpropranololanddibenzyline, which block adrenergic inhibitory and excitatory receptors respectively, suggest that both these receptors are present in the bladder. The former drug increased bladder tone, the latter had an atropine‐like effect on the micturition contraction and an excitatory influence on the micturition reflex. Finally,guanethidine, which blocks the adrenergic neuro‐muscular junction, had an excitatory effect on the bladder and a facilitatory effect on the micturition reflex in addition to its presynaptic blocking effect. These results support previous hypotheses of a sympathetic inhibition and absence of parasympathetic activity during the collecting phase, and of bladder pressure as the determinant of the micturition threshold.
The Mechanical Parameters of Myocardial Contraction Studied zit a Constant Length of the Contractile Element
Authors: Edman K. A. P. , Nilsson E. 
Published: December 2008

AbstractEdman, K. A. P. and E. Nilsson.The mechanical parameters of myocardial contraction studied at a constant length of the contractile element. Acta physiol. scand. 1968.72. 205–219.The time course of the active state, the force‐velocity relation and the series compliance were investigated in isolated papillary muscles of the rabbit.—The force‐velocity curve defined at a precise length state of the contractile element and at a given time after the stimulus could be fitted by Hill's equation. The shape of the curve remained constant during the activity period, indicating that the ability to produce motion and the ability to produce tension undergo parallel changes during a myocardial contraction cycle.—The active state, at a given length of the contractile unit, had a slow onset (1/3–1/2 of the entire activity period being needed for attainment of the maximum) and did not form a distinct plateau. The time course of the active state was critically dependent on the degree of extension of the contractile unit. Evidence is presented that the duration of the active state is not definitely programmed at the start of the contraction; its final outcome is determined by the amount of shortening of the contractile element during the activity period.—The stiffness of the series elastic element, at a given tension, was independent of the intensity of the active state. This fact supports the view that the active. force‐producing structures in the cell do not contribute substantially to the series compliance of the cardiac muscle.
Blood Flow and Flow Distribution in the Small Intestine of the Cat as Analysed by the Kr85Wash‐Out Technique
Authors: Kampp Mogens , Lundgren Ove 
Published: December 2008

AbstractThe blood flow and flow distribution of the small intestine of cat were studied at various levels of vascular smooth muscle tone by means of the Kr85wash‐out technique. At “resting” total intestinal blood flow about 80 per cent of flow was distributed to the mucosa‐submucosa, where the flow rate amounted to 40–80 ml/min × 100 g. Blood flow of the muscularis was then 10–20 ml/min × 100 g. As total intestinal blood flow was increased by constant, intra‐arterial infusions of isopropylnoradrenaline a larger and larger part of intestinal blood flow was distributed to a highly vascularized part of the intestine probably located in the submucosa and adjacent parts of the mucosa. At intense vasodilatation (venous outflow 225 ml/min × 100 g) about 60 per cent of total flow passed through these intestinal structures, the blood flow of which amounted to 800–1000 ml/min × 100 g. The blood flow of the rest of the mucosa‐submucosa increased concomitantly to 150–200 ml/min × 100 g and that of the muscularis to 35–40 ml/min × 100 g.
The Effect of Calcium on the Skeletal Muscle Membrane after Treatment with Phospholipase C
Authors: Albuquerque E. X. , Thesleff S. 
Published: December 2008

AbstractThe effects of phospholipase C on the muscle membrane were studied by the recording of the resting membrane potential, the input resistance and the action potential generation in single fibres of the isolated extensor digitorum longus and soleus muscles of the rat. Incubation with phospholipase C abolished spike generation, depolarized the fibres by 15–20 mV and increased the ionic permeability of the membrane as shown by a fall of about 40 per cent of the “input” resistance. Removal of the enzyme by washing the preparation with Krebs‐Ringer solution did not restore membrane exitability. the resting membrane potential nor the input resistance of the fibres. When the external calcium concentration was raised from the normal 2 mM to 15 mM the muscle fibres repolarized and action potentials with a reduced rate of rise and amplitude were recorded. No recovery of the input resistance occurred. When the calcium concentration was brought back to 2 mM the fibres again depolarized and became inexcitable. Potassium (10 or 15 mM), caesium (10 mM) or rubidium (6 mM) antagonized the aforementioned effects of 15 mM calcium. It was concluded that phospholipase C irreversibly affected the muscle membrane and that an increase in the external calcium ion concentration only functionally restored some of the membrane properties, i.e., spike generation and the resting membrane potential. The results support the view that the hydrophilic head of certain membrane phospholipids is connected with passive ion transport in the electrogenic membrane.
Response of Isolated Muscle Spindles to Single Transient Stretches*
Authors: Jahn Samia Al Azharia 
Published: December 2008

ABSTRACTThe smallest stretch of isolated frog muscle spindles which regularly evoked an afferent discharge was 8 ± 2 μ measured as the displacement of a graphite granule placed above the equatorial region 5–8 mm from the distal tendop of the muscle. The threshold deformation (T) was independent of an increase in the rate of deformation from 0.016 xT/msec to 1.0 × T/msec and of an increase in the initial elongation from 10 to 25 per cent above equilibrium length. The rate below which the spindle did not respond to stretch was 0.01 × T/msec. With low rates of stretch (0.016–0.03 × T/msec) the afferent response occurred before the deformation was completed and with higher rates (0.1–1.0 × T/msec) after it was completed.A second afferent response was elicited when the deformation exceeded 2 times threshold (rate of stretch: 0.1–0.3 × T/msec) or 3–4 times threshold (rate of stretch: 0.6–2.7 × T/msec). The shortest interval between two afferent responses was 2 msec.Depending on the timing of the spontaneous afferent activity and the spontaneous intrafusal contractions the afferent response evoked by a stretch was abolished or its latency was shortened or increased.
Effect of Adrenaline, Noradrenaline, Angiotensin and Renal Nerve Stimulation on Intrarenal Distribution of Blood Flow in Dogs
Authors: Aukland Knut 
Published: December 2008

ABSTRACTThe acute effect of adrenaline, noradrenaline. angiotensin and renal nerve stimulation on intrarenal blood flow was studied in 15 dogs. Local clearance of hydrogen gas measured polarographically with 2–4. needle‐shaped platinum rlectrodes in the outer medulla served as indicator for medullary blood flow. Total renal blood flow was measured simultaneously with electromagnetic flowmeter. Adrenaline, noradrenaline and angiotensin infused i.v. or into the renal artery over a period of 5–15 min reduced outer medullary hydrogen clearance and total renal blood flow to 25–90 per cent of control, and on an average to the same extent. Renal nene stimulation produced the same pattern with flow reduction to 50–75 per cent of control. Since changes in total renal blood flow mainly reflect changes in cortical per‐fusion. it is concluded that resistance to flow was increased proportionately in the cortical and juxtamedullary circulation. Considerable local xrariations in response of outer medullary hydrogen clearance observed with all stimuli suggested local differences in vasoconstrictor response, but no consistent difference between cortex and medulla.