bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Influence of Adrenaline, Nor‐adrenaline, and Acetylcholine on the Electrocardiogram of the Isolated Perfused Guinea‐pig Heart
Authors: JOHANSSON BENGT , VENDSALU AADO 
Published: December 2008

Summary.

The effect of increasingly large doses of adrenaline, nor‐adrenaline, and acetylcholine on the electrocardiogram of the isolated, perfused guinea‐pig heart was studied before and after administration of dibenamine and atropine, respectively.
The threshold value for nor‐adrenaline to cause electrocardiographic changes was lower than that for adrenaline. The chronotropic effect seemed to be the same for the two substances at low doses, while at higher doses nor‐adrenaline seemed to be the more effective positive chronotropic agent. Cardiac arrhythmias were observed in about one‐third of the experiments and nor‐adrenaline appeared to be as potent as adrenaline in developing conduction disturbances and evoking ectopic discharges. Adrenaline increased the amplitude of the P wave, while nor‐adrenaline had no effect on the amplitude. There was no difference between the two substances as to the changes in the P—R interval, Q—T duration, S—T segment, or on the T waves. At lower doses the P—R interval was shortened; a prolongation was seen at high doses. The Q—T duration was first prolonged, but 30 to 60 secs later a shortening appeared. The T waves showed reduction in amplitude, so that a previously positive or negative T wave became less positive or less negative, respectively. In some hearts the opposite results were seen. At high doses a previously positive T wave could become negative and vice versa.
After dibenaminization, slightly higher threshold values of adrenaline and nor‐adrenaline were necessary in order to produce electrocardiographic changes. At higher doses of the two substances, dibenamine could not abolish or decrease the chronotropic effect or electrocardiographic contour changes.
At lower doses acetylcholine produced decreased auricular rate, with increasing doses heart block occurred, partial or complete. A propensity to evoke auricular fibrillation was evident. Ectopic auricular or ventricular discharges occurred. The P wave often became notched, its amplitude and duration decreased. In some experiments the Q—T duration was shortened and was followed by a lengthening. The T wave amplitude increased so that a previously positive or negative T wave became more positive or more negative, respectively.
The inhibitory effect of acetylcholine was abolished by atropine. High doses of acetylcholine caused acceleration of the heart rate in atropinized hearts.
Enzymic Oxidation of Some Substances Related to Histamine
Authors: LINDELL S.‐E. , WESTLING H. 
Published: December 2008

Summary.

The action of histaminase and amine oxidase preparations on seven histamine‐like substances was examined. The enzyme preparations were obtained from pig and cat kidney and from guinea‐pig and rabbit liver.
Some of the substances studied were found to be oxidized by amine oxidase preparations but not by histaminase.
1‐methyl‐4βaminoethyl imidazole was found to be a good substrate of histaminase. It was also oxidized by amine oxidase preparations
The Mechanism of Establishment of Secretory Potentials in Sublingual tiland Cells.
Authors: LUNDBERG ANDERS 
Published: December 2008

Summary.An attempt has been made to analyse the mechanism of establishment of the secretory potential over the outer gland cell membrane in the sublingual gland of the cat, as well as its importance for the secretion of salt and water.Double‐barrelled microelectrodes were inserted into gland cells permitting recording of the intracellular potential with current flow through one channel to change the membrane potential. The secretory potential over the outer membrane could still be evoked when the membrane potential had been raised to more than 100 mV. It is concluded that this secretory potential is due to an active transport of ions over the outer membrane and assumed to be an inward transport of anions.The resistance between the cell interior and the external medium measured with this technique was about 2 Mω in the resting state and 1.8 Mω during activation. Measurement has also been made of the resistance between the external medium and the lumen of the gland cell tubule and of the ratio of the resistances offered by the inner and outer gland cell membranes to a current passed between the external medium and the lumen. On the basis of these measurements and the assumption that the gland cell tubule can be considered as a core conductor the specific resistances of the outer and inner gland cell membrane were derived to 18 respectively 11 ohm cm2 in the resting cell. With activation there was no significant change in the resistance of the inner cell membrane, whereas the resistance of the outer membrane decreased by about 50 per cent.The anionic content of the saliva secreted by a number of gland cells with a certain area of outer membrane has been compared with the amount of current needed from an external battery to equal the secretory potential over this area of outer gland cell membrane. The probable order of magnitude of the active anionic transport is discussed in view of these findings.The hypothesis is forwarded that secretion of salt and water largely is caused by active transport of anions (mainly or exclusively chloride) over the outer gland cell membrane.
Effect of Tributyrin on Circulation and Respiration.
Authors: WRETLIND ARVID 
Published: December 2008

Summary.The effects of tributyrin on circulation and respiration have been studied by injection of a tributyrin emulsion.On intravenous injection, the effect of tributyrin on circulation is characterized by rapidly appearing bradycardia and a fall in blood pressure, followed by a rise in blood pressure.Bradycardia and the fall in blood pressure are inhibited by vagotomy and procaine. They do not appear with injection into the left ventricle, aorta or large arteries. The effect is probably‐elicited through receptors with afferent pathways in the vagus, and located to the right side of the heart or the lungs. The rise in blood pressure is largely due to contraction of peripheral blood vessels. This rise is not inhibited by tetraethylammonium, hexamethonium, dihydroergotamine, ergotamine or procaine.In the heart‐lung preparation, tributyrin decreases the heart action. The blood flow in the abdominal aorta is reduced, together with a rise in blood pressure after injection of tributyrin.The effect on respiration is characterized by apnoea with a rapid onset, followed by hyperpnoea. Apnoea is not elicited after vagotomy, but appears after administration of atropine or procaine. Injection into the left ventricle, aorta or large arteries does not produce apnoea. Apnoea is probably evoked via receptors in the right side of the heart or the lungs. The hyperpnoea is considered to be produced by central stimulation.Bradycardia, the fall in blood pressure and apnoea associated with injection of tributyrin seem to be elicited in the same way as the Bezold‐Jarisch reflex described earlier.Tributyrin is found to have neither an inhibitory nor a stimulating effect on the superior cervical ganglion.The LD50 of tributyrin on intravenous injection into mice is 320 ± 11 mg/kg.
Eine oximetrische Methode zur Kreislaufzeitmessung am menschlichen Gehirn.
Authors: NILSSON NILS JOHAN 
Published: December 2008

Zusammenfassung.Eilie Methode zur Messung der Kreislaufzeit durcb das menschliche Gehirn unter Verwendung von zwei Oximetereinheiten wird besehrieben.Die Sauerstoffsättigung des arterialisierten Ohrblutes und die des venösen Blutes im Bulbus jugularis werden gleichzeitig registriert mit Hilfe einer Ohreinheit bzw. einer Cuvetteneinheit, die auf der Punktionskanüle des Bulbus jugularis montiert ist. Das Jugularisblut wird von einer Rekordspritze mit Synchronmotorantrieb gleichmässig durch die Einheit gesogeu.Durch kurzdauerndes Stickstoffatmen werden rasche Änderungen der Sättigung des Blutes hervorgerufen. Die kürzeste Kreislaufzeit wird als Abstand zwischen korrespondierenden Punkten der Arterien‐ und Venenkurve gemessen.Nach Injektionen von NaCl oder Evans blue in die A. carotis communis wurden Befunde erhoben, die darauf deuten, dass die Gehirndurchblutung unmittelbar naeh einer intraarteriellen Injektion vorübergehend zunimmt.
Der Off‐Effekt im menschlichen Elektroretinogramm.
Authors: HECK J. 
Published: December 2008

Zusammenfassung.Nach Helladaptation findet man im menschlichen ERG bei intermittierender Belichtung neben einer komplexen On‐Antwort, die dem Einzelreiz‐ERG von congenital Nachtblinden entspricht, einen doppelten positiven Off‐Effekt. “On” und “Off” weisen spiegelbildliches Verhalten auf. Die Abhangigkeit des Off‐Effektes vom Adaptationszustand und von der Lichtintensität wird untersucht, und das Zustandekommen seiner doppelten Konfiguration diskutiert.
The Respiratory Gaseous Exchange After a Short Burst of Exercise.
Authors: ERIKSON. H. 
Published: December 2008

Summary.Spirometric investigations of the respiratory gaseous exchange during resting, not basal, conditions and the recovery after a 70 yard sprint are reported.It is shown that around 10 minutes after connection with the spirometer fairly constant values for oxygen uptake and carbon dioxide output were obtained. These resting values were regained shortly after the exercise. The time used for elimination of excess carbon dioxide was longer and more constant, and showed greater interindividual differences than the time required for covering the oxygen debt.Well trained subjects with good results in track competitions showed the shortest recovery times. Trained subjects with fair to poor results had recovery times overlapping the recovery times of untrained subjects in good physical condition.
Lactic Acid Content in Human Venous Blood During Hypoxia at High Altitude.
Authors: HARBOE M. 
Published: December 2008

Summary.The concentration of lactic acid in human venous blood has been determined during hypoxia — the subjects breathing atmospheric air at high altitudes. Lactic acid concentration increases, depending on the degree and duration of hypoxia.Apart from heights of 15,000 to approximately 20,000 feet, where the lactic acid concentration increases simultaneously with increasing disability, such concentration is poorly correlated to the functional disability during hypoxia.
The Effect of Atropine on the Acidity of a Denervated Gastric Pouch.
Authors: NORDGREN BENGT , ÖBRINK KARL JOHAN 
Published: December 2008

Summary.In experiments in pouch dogs it was shown that after administration of atropine the volume secretion rate declines much sooner than the acidity. The time lag was mainly due to the remaining volume in the gastric pouch (The ‘lake hypothesis’ of Öbrink1948). Earlier observations of other authors that atropine could cause an increased acidity were, however, confirmed especially in cats where HC1 was instilled and a permeability coefficient for the hydrogen ions calculated. Atropine caused a slower decrease in acidity, which could be explained by a decreased permeability for the hydrogen ions. (The diffusion theory of Teorell1933, 1947.) The action of atropine on the acidity regulation was thought to depend on its effect on the vascularisation of the gastric mucosa.
The Available Glycogen in Man and the Connection between Rate of Oxygen Intake and Carbohydrate Usage.
Authors: HEDMAN RUNE 
Published: December 2008

Summary.The type of work was ski running at a constant speed on a 750 m circular track set up on level ground. Four well trained male subjects performed this work to the point of exhaustion. During 150–160 min three of the subjects were able to run at a work intensity which corresponded to an oxygen intake of 3.6‐4.1 l/min. (The oxygen intake for the fourth subject was 3.4‐3.9 l/min during 120 min.) The total energy expenditure during this time was 2,000–3,000 Cal; the pulmonary ventilation rose to a mean of 90 l/min and the heart rate was 160–190 beats/min. By determination of the respiratory metabolism the quantity of oxidized carbohydrates was calculated.The RQ values remained during the whole run at a practically constant level. One subject, who had reduced his glycogen depot by 445 g, continued to get 55 % of his calorie need from carbohydrates, although hypoglycemic symptoms were present.The blood lactic acid concentrations at the end of these long periods of work were slightly increased (20 mg %).
A Modification of the Thiocholine Method for the Determination of Cholinesterase. I. Biochemical Evaluation of Selective Inhibitors.
Authors: HOLMSTEDT BO 
Published: December 2008

Summary.Biochemical controls of the thiocholine method for the determination of cholinesterase have been performed both with partially purified enzyme and with enzymes from the cat.The electrometric method that has been used for the determinations permits the use of the same pH and the presence of all the reagents used histochemically. The inhibition curves of aceto‐and butyrocholinesterase activity using DFP, Mipafox, BW 284c51, 302 IS and 306 IS have been determined. Of these inhibitors BW 284c51 and Mipafox were shown to be the most selective in the histochemical incubation solutions. The compounds were also tested against the crude enzymes from the cat, and showed equally good inhibitory properties.The use of selective substrates and inhibitors is discussed. It is concluded that if biochemical controls of the thiocholine method are to be of value they must be made in exactly the same solution as used histochemically. The pH and the concentration of inhibitor in the solution must be based on controls run in vitro or erroneous localisation of the two types of cholinesterases may result.
The Mechanism of the Vasodilator Effect of Adrenaline. II. Influence of Anesthetics on the Depressor, Pressor and Lactic Acid Stimulating Effects of Adrenaline.
Authors: LUNDHOLM LENNART 
Published: December 2008

Summary.The influence of different anesthetics on the depressor and pressor as well as the lactic acid stimulating effects of adrenaline were investigated in cats and compared with the corresponding effects in unanesthetized animals. Adrenaline was infused intravenously for 5 minutes in increasing doses ranging from 0.1 to 24.3 μg per kg body weight per minute.In unanesthetized animals the depressor effect was very slight, although adrenaline reduced the total peripheral resistance; this probably because the blood‐pressure regulation was better than in the anesthetized animals. In most of the latter the depressor effect emerged, but its magnitude varied considerably according to the anesthetic employed. Broadly speaking, the depressor effect showed a statistically significant correlation both to adrenaline's ability to increase the lactic acid content of the blood and to the basal blood‐pressure level.The same factors that amplified the depressor effect of adrenaline weakened its pressor effect. The latter was negatively correlated to the basal blood‐pressure level and to the lactic acid producing capacity of adrenaline. Further, the anesthetic had a direct inhibitory effect on adrenaline's vasoconstrictor action.In the individual cases the influence of the different anesthetics on adrenaline's circulatory effect was explained as follows. Ether amplified the lactic acid production and raised the basal blood pressure in relation to adrenaline's effect on unanesthetized animals, the depressor effect was very pronounced and the pressor effect greatly weakened. Urethane did not influence the lactic acid production, but elevated the basal blood pressure; the depressor effect was distinct but the pressor effect weakened. Evipan did not demonstrably influence either the lactic acid production or the basal blood pressure; the depressor effect was somewhat greater and the pressor effect somewhat less than in unanesthetized animals. Dial inhibited the lactic acid production without definitely influencing the basal blood pressure; the depressor effect was weak but the pressor effect amplified. Chlo‐ralose inhibited the lactic acid producing action of adrenaline but concurrently raised the basal blood pressure; these effects on adrenaline's action tended to counterbalance each other.Noradrenaline had neither a lactic acid stimulating nor a depressor effect on ether‐anesthetized cats.
Supersensitivity Caused by Denervation and by Cholinesterase Inhibitors.
Authors: STRÖMBLAD B. C. R. 
Published: December 2008

Summary.Experiments on the cholinesterase activity of homogenates of normal and denervated salivary glands are described.The percentage decrease after various types of denervations was the same as found earlier (Strömblad 1955 b) when the supernatant of the homogenate was estimated.The changes in enzymic activity after denervations were compared with those found when mintakol (or TEPP) was injected into the glands via the secretory duct in amounts causing supersensitivity.It was inferred that the supersensitivity found after denervations could not be wholly due to a decrease in cholinesterase activity. In case of preganglionic denervation it is doubtful if enzyme decrease could play any part in the supersensitivity, while in case of postganglionic parasympathetic denervation it was very suggestive. Experiments are also described which are in accord with a suggestion previously proposed that the difference in sensitivity between a pre‐and postganglionically denervated parotid gland is due to the greater fall in cholinesterase after postganglionic as compared with preganglionic denervation.The supersensitivity caused by excision of the superior cervical ganglion could hardly be attributed to a decrease in cholinesterase activity of the gland.
The Albumin/Globulin Ratio in Plasma and Exudate of Chicks Suffering from Exudative Diathesis.
Authors: DAM HENRIK , HARTMANN S. , JACOBSEN JOHANNE E. , SØNDERGAARD EBBE 
Published: December 2008

Summary.Tiselius‐electrophoresis was carried out on plasma from chicks on a normal commercial chicken ration, on a torula yeast containing artificial diet with or without vitamin E, and on exudate from chicks on the last mentioned diet.The albumin/globulin ratios were found to be largely the same for plasma of chicks on the normal diet, on the diet with torula yeast supplemented with vitamin E, and for the exudate. Lower albumin/globulin ratios were found only for plasma of chicks having exudate.The mobilities of the various plasma protein fractions were not influenced by the dietary regimen.The protein fractions in the exudate had the same mobilities as the corresponding fractions in the plasmas.
Effects of Histaminase Inhibitors on the Blood Pressure Responses in Dogs to Histamine Injected into the Renal Artery.
Authors: LINDELL SVEN‐ERIC 
Published: December 2008

Summary.1. The effects on the dog's blood pressure of histamine injected by vein or into the femoral or renal artery have been studied.2. The effects of two histamine analogues, which were not oxidized by histaminase in vitro were also studied under the same conditions.3. As judged from the relative effectiveness of histamine injected by these routes the kidney had a considerable capacity to remove injected histamine from the circulating blood.4. Histaminase‐resistant histamine analogues were not removed as effectively as histamine by the kidney.5. Histaminase inhibitors, such as aminoguanidine, B1‐pyrimidine and isonicotinylhydrazine potentiated the depressor responses to histamine given into the renal artery but not those to histamine given into the femoral artery or by vein.6. The depressor responses to the histaminase‐resistant histamine analogues were not potentiated by the inhibitors.
Fibrinolytic Activity Derived from Guinea Pig Serum by Peptone.
Authors: OLESEN E. S. 
Published: December 2008

Summary.1) Peptone, in combination with an isoelectric precipitation, releases fibrinolytic agents in normal guinea pig serum. These results confirm, with a different method, the finding of Ungar et al.2) The formation of a plasminogen activator and an active protease is demonstrated.
Life Cycle of Granulocytes and Lymphocytes Determined by Making Use of 59Fe Labelled Haemin as a Tracer
Authors: RESEGOTTI LUIGU 
Published: December 2008

Summary.In granulocytes and lymphocytes separated from the blood of the rabbit the incorporation of radioactive 59Fe into the haemin fraction was investigated.Evidence is presented that the iron is incorporated into the haemins during the formation of these cells and remains in them during their life time. From the change of the specific activity of the haemin iron with time the average life span of both lymphocytes and granulocytes can thus be calculated.The mean age of the granulocytes was found to be 8.8 days. It is presumably composed of two populations of about the same frequency but varying life time, one having a life span of 4.4, the other of 13.2 days. The mean age of 8.8 days is identical with the result obtained by Ottesen from 32P data of DNA isolated from granulocytes.A very appreciable part of lymphocytes has a life span amounting to 145 days; 10 % only having one of 3 days. An almost identical result was arrived at by Ottesen in his DNA studies. A part of the lymphocytes entering the blood stream is still going on to incorporate haemin iron, thus to build up haemin.
Further Studies on the Intestinal Glucuronide Synthesis
Authors: HARTIALA K. J. V. , LEIKKOLA P. , SAVOLA. P. 
Published: December 2008

Summary.Intragastric feeding of cinchophen in dog results in a significant increase in the portal blood glucuronide concentration in addition to the rise in hepatic and femoral blood glucuronide contents. Ligation of the common bile duct does not prevent the increase in portal blood glucuronide concentration.These observations are taken as a further evidence to support our in vitro studies with tissue slices. These have shown that the mucous membrane of the gastrointestinal tract participates in the detoxication mechanisms and is capable to conjugate glucuronides with suitable substances present in the environment.
Blood Volume in Albino Rats Determined by the Plasma Dye Method
Authors: JØRGENSEN MOGENS , VOIGT JØRGEN , JENSEN ELSE M. 
Published: December 2008

Summary.The average value of 31 determinations of circulating blood volume in adult albino rats by a simple plasma dye method using Evans' dye was found to be 5.92 ± 0.21 ml/100 g body weight with a variation from 3.68 ml/100 g to 8.24 ml/100 g.
Co‐ordinated Changes in Temperature Thresholds for Thermoregulatory Reflexes
Authors: von EULER CURT , SÖDERBERG ULF 
Published: December 2008

Summary.1. In lightly anaesthetized cats and rabbits the threshold temperatures for several temperature regulating reactions, i. e., onset and cessation of shivering and cutaneous vasoconstriction, were repeatedly determined when stimulating the animals in different ways2. It was found that various stimuli, such as nociceptive stimulation, pinna reflex, and electrical stimulation of the midbrain tegmentum which all activated the electroencephalogram and the gamma motor system, tended to raise the temperatures at which both heat‐producing and heat‐dissipating reflexes are brought into action with a rise in body temperature as a consequence.3. Similar shifts of the temperature for thermo‐balance were obtained by systemic infusion of adrenaline and noradrenaline. Changing the composition of the inspired gas was also found to influence thermoregulation.4. Stimuli which inhibited the activity of the gamma motor system and evoked a synchronized cortical activity, e. g. stroking the back of the animal, lowered the threshold temperatures with as light fall in body temperature as a result.5. The results support the view that the body temperature is set at different levels in different states of activity.