bluuebunny/crossref_metadata_2025 huggingface dataset:
The Effect of Noradrenaline and Adrenaline on Hepatosplanchnic Hemodynamics, Functional Capacity of the Liver and Hepatic Metabolism
Authors: Krarup Niels
Published: December 2008

Cats in the postabsorptive state and anesthetized with chloralose were used for the experiments. Following a control period noradrenaline and adrenaline at doses of 0.5, 1.0, 2.0, and 5.0 μg/kg/min were infused continuously for about an hour into a femoral vein. Noradrenaline caused a pronounced constriction of the hepatic artery and a slight increase in the mesenteric vascular resistance. Small doses of adrenaline had a slight dilatory effect on the hepatic artery and mesenteric vessels whereas the largest dose caused a slight constriction in both these vascular beds. Neither of the drugs changed the portal venous resistance. The catecholamine infusions resulted in hepatic glycogenosis and glycolysis, but neither the splanchnic elimination of ethanol, the secretion and composition of bile, excretion of Indocyanine Green nor the splanchnic oxygen consumption were affected, indicating that the number of sinusoids perfused was not changed. A slight effect on the hepatic clearance and extraction ratio of Indocyanine Green was, however, observed. The results indicate that although the infusion of catecholamines in the present doses is accompanied by marked changes in hepato‐splanchnic hemodynamics and liver metabolism, the intrahepatic distribution of blood flow is not subject to gross alterations. The existance of catecholamine dependent sphincter activity in the hepatic sinusoids observed in transillumination studies have not been confirmed by the present experiments.
An Investigation of the Action of Ouabain on the Sodium Efflux in Barnacle Muscle Fibres
Authors: Bittar E. Edward , Chen Stephen S. , Danielson Bo G. , Tong Edmund Y.
Published: December 2008

Measurements of radiosodium efflux were carried out on single fibres from the barnacleBalanus nubilusorB. aquila, using the micro‐injection technique. 10‐4M ouabain caused an average fall of 68% of the Na efflux, the minimal effective concentration beingca.10‐7M. Internal application of 4 × 10‐3M ouabain was without effect. Abolition of the ouabain‐sensitive component with ouabain, followed by raising the external K concentration to 30 mM, resulted in a marked rise in the residual Na efflux. Stimulation of the ouabain‐insensitive Na efflux was also seen after reducing the external pH, as well as after microinjecting CaCl2but not MgCl2. Uncoupling of the active transport system by K removal, followed by external application of ouabain, and subsequent acidification of the bathing medium, led to stimulation which was considerably greater than that taking place when the Na efflux was uncoupled by K removal and then stimulated by external acidification.
Nervous and Humoral Control of Vascular Resistance during Acute Hemorrhagic Hypotension in Rabbits
Authors: Aars H. , Akre S.
Published: December 2008

Peripheral vascular resistance in anesthetized rabbits quickly increased during hemorrhagic hypotension, despite almost unchanged sympathetic nerve activity. Simultaneous measurement of blood flow to denervated and innervated kidneys showed that the acute rise of renal vascular resistance during hypotension was independent of innervation. In other animals, the left, innervated kidney was perfused with blood from either the host or a donor rabbit, by means of a pump. Renal vascular resistance invariably rose during systemic hypotension when the kidney was perfused with blood from the rabbit subjected to hemorrhage, but not when perfused with blood from a normovolemic animal. The results support the view that increased peripheral vascular resistance during the first minutes of hemorrhagic hypotension is caused by humoral agents, rather than by increased sympathetic activity.
Oxygen Uptake during Maximal Work at Lowered and Raised Ambient Air Pressures
Authors: Fagraeus L. , Karlsson J. , Linnarsson D. , Saltin B.
Published: December 2008

The maximal aerobic power (Vo2max) was measured in 12 subjects exercising on a bicycle ergometer breathing air at 0.68, 1.0 and 1.40 ATA ambient pressures. Seven of the subjects were also investigated at 2.0 and 3.0 ATA. Vo2max averaged 3.67 1·min‐1 STPD at 1.0 ATA and was reduced by 14 per cent at 0.68 ATA (p < 0.001), while at 1.40 ATA Vo2max was increased by 9 per cent (p < 0.001). The increased PIO2 at the two highest pressures did not result in any further improvement of vo2max compared to 1.40 ATA. At all pressures changes in endurance time parallelled those of Vo2max. Ventilation decreased markedly as ambient pressure increased with a concomitant rise of PACO2 up to a mean value of 43 mm Hg at 3.0 ATA as compared to 32 mm Hg at 1.0 ATA. It is concluded that moderate hyperoxia produced by increased ambient air pressure enhances circulatory transport of oxygen in maximal exercise, and that the working muscles have an aerobic potential exceeding what the circulation normally can offer.
An Indicator‐Dilution Method for Studying Intestinal Hemodynamics in the Cat
Authors: Blber Björn , Lundgren Ove , Stage Lars , Svanvik Joar
Published: December 2008

An indicator‐dilution technique is described for studying intestinal mucosal red cell and plasma flow and volume quantitatively and muscularis red cell and plasma flow and volume qualitatively. The technique involves a close intra‐arterial injection of an intravascular β‐radiating tracer and its detection with sensoring devices placed in the gut lumen and outside the intestine at the antimesenteric border. Knowing the amount of tracer injected and total venous outflow, it is possible to estimate regional flow from the height of the registered curve and regional blood volume from its area. Since the volume of the region monitored by the detector depends on the energy level of the β‐radiation, 32P‐labelled red cells and plasma colloids, used in this study, were monitored from the whole mucosa, while 108Au‐labelled plasma particles were registered only from the villi. This paper presents the theoretical background of the technique and some model experiments.
Effect of Hemorrhagic Hypotension on the Distribution of Renal Cortical Blood Flow in Anesthetized Dogs
Authors: Aukland K. , Kirkebö A. , Löyning E. , Tyssebotn I.
Published: December 2008

The distribution of renal cortical blood flow was studied in seven Nembutal anesthetized dogs in control periods, during hemorrhagic hypotension and after retransfusion. Local cortical blood flow was measured as hydrogen clearance recorded simultaneously from 3 to 6 platinum electrodes inserted into inner and outer half of the cortex. Total renal blood flow (RBF) was measured by electromagnetic flowmeter. In control periods flow averaged 3.47 ± 0.83 ml/min×g in outer cortex and 3.61 ± 0.86 ml/min × g in inner cortex. Bleeding to mean arterial pressure of 50 mm Hg in the course of 5–36 min in 5 expts. caused a proportional reduction of RBF and average flow in outer and inner cortex to 40–60 % of control, with further reduction to 10–30 % with maintenance of hypotension for 2 h. Bleeding to 70 mm Hg in 2 expts. gave princpially the same response. All electrodes showed a similar response and the percentual deviation between electrodes did not increase during hypotension. Thus no evidence was obtained for patchy or segmental ischemia or for regional redistribution of cortical blood flow. Retransfusion gave only incomplete restoration of flow.
Two Types of Lateral Line Afferents in the Eel (Anguilla anguilla)
Authors: Alnæs Egil
Published: December 2008

The spontaneous and evoked discharges of eel lateral line sensory organs have been investigated. Each afferent nerve fibre has a well defined punctate receptive field, corresponding to a single canal organ. No axons were found to innervate more than one of these. All afferents pass through the Rarnus lat. dors. N.X. to the medulla oblongata. No peripheral unidirectional synapses exist in the nerve. Afferent axons are myelinated and belong to a large calibre (mode 12 μm) and a small calibre (mode 3 μm) axonal population in the nerve. The nerve contains about 800 myelinated axons at the level of its medullary entry, subserving approximately 100 sensory organs. In both groups rates of spontaneous discharge range from 0 c/s‐50 c/s. Both groups include extremely mechano‐sensitive units, and less sensitive units. The main difference between the slowly and rapidly conducting units is the more regular spontaneous firing pattern of the former group.
Effect of Spinal Transection on the Metabolism of 5‐Hydroxyindoles Formed in vivo from3H‐Tryptophan in the Rat Spinal Cord
Authors: Schubert Johan
Published: December 2008

The nerve impulse flow in 5‐hydroxytryptamine (5‐HT) neurons descending to the caudal part of the spinal cord of rats was interrupted by a spinal transection. At various time intervals after the operation3H‐tryptophan was administered i.v. and the accumulations of labelled 5‐HT and 5‐hydroxyindoleacetic acid (5‐HIAA) in the cord were determined. 6–8 days after the section the cord caudal to the lesion was almost depleted of 5‐HT and very little3H‐5‐HT was formed from the labelled precursor. Between 8 and 24 h post‐lesion the level of 5‐HT was increased by 20 % below the lesion, whereas the accumulation of3H‐5‐HT was markedly reduced. Immediately after the transection the endogenous 5‐HT level as well as the3H‐5‐HT accumulation were unchanged in the caudal cord. The accumulation of3H‐5‐HIAA below the section was reduced at all time intervals after the operation. The specific activity of tryptophan seemed to be increased following nerve section. The results indicate that 5‐HIAA synthesis is controlled by nerve impulse activity. The synthesis of 5‐HT was not directly dependent on neuronal activity or tryptophan levels but seemed to be inversely correlated to the endogenous 5‐HT level.
Peripheral Inhibition of Eel Lateral Line Receptors as Caused by Antidromic Sensory Terminal Invasion
Authors: Alnæs Egil
Published: December 2008

No evidence of efferent inhibitory activity on eel lateral line sensory cells has been found in a number of different types of experiments. Proximal transection of the lateral line nerve induces no changes in the ongoing activity from the sensory cells, even in the uncurarized, un‐anesthetized animal. Stimulation of peripheral nerve filaments induces no inhibition of afferent spontaneous and/or evoked activity, either ipsilaterally or contralaterally. No spontaneous or evoked efferent activtiy could be recorded from proximal nerve filaments. Antidromic invasion of sensory terminals resets the ongoing spontaneous activity. In the intervening interval the mechanical and electrical thresholds of these sensory units are similarly elevated. Antidromic invasion is suggested to be the phenomenon reported as peripheral inhibition by Hashimoto et al. (1970).
On the Relative Importance of Extra‐Neuronal Uptake of Noradrenaline Released by Nerve Stimulation in the Rabbit Heart
Authors: Junstad Marianne , Stjärne Lennart , Wennmalm ÅKe
Published: December 2008

Drugs known to inhibit the extra‐neuronal uptake of noradrenaline were given to the sympathetically stimulated, perfused rabbit heart, and the subsequent change in the overflow of transmitter was studied. Normethanephrine (10‐5M) increased the outflow of noradrenaline on nerve stimulation by about 25%, while lower doses were ineffectual. However, in the dose mentioned, the drug did not potentiate the earlier reported increase in overflow caused by desmethylimipramine (5.5 × 10‐7M). On nerve stimulation, intact noradrenaline made up 83% of the increase in radioactivity in the perfusate before, and 94% after, inhibition of the extra‐neuronal uptake of noradrenaline. It is concluded that extraneuronal uptake of noradrenaline, released by sympathetic nerve stimulation, plays a small but significant role in the inactivation of the transmitter from the neuro‐effector junctions. The findings are discussed with regard to earlier observations where phenoxybenzamine, another potent inhibitor of extra‐neuronal uptake, was found to increase the overflow of transmitter on nerve stimulation more than could he expected from its uptake‐inhibiting properties alone.
The Effect of Stimulation of the Cervical Sympathetic Chain on Retinal Oxygen Tension and on Uveal, Retinal and Cerebral Blood Flow in Cats
Authors: Alm Albert , Bill Anders
Published: December 2008

The effects of stimulation of the cervical sympathetic chain on blood flow through the retina, the different parts of the uvea, different parts of the brain and some other tissues were studied in cats. 5 Hz reduced the oxygen tension in the vitreous body close to the retina in 5 expts. of 6. 15 μm labelled microspheres were used for quantitative determinations of blood flow. Unilateral stimulation at 10 Hz was performed for 1 min in 9 normocapnic and in 4 hypercapnic cats and for 15–30 min in 5 normocapnic cats. The results suggest that blood ffow through the innermost layers of the retina is influenced by sympathetic stimulation. The vascular resistance within the uvea was much increased in all three groups with no indications for “autoregulatory escape”. The effect was most pronounced in the ciliary processes and least in the ciliary muscle. “Autoregulatory escape” was seen in the parotid gland, the tongue and the masseter muscle, where 1 min stimulation caused mean reductions in blood flow by 82–99% compared to 6–56% after 15–30 min stimulation. Cerebral blood flow showed no statistically significant reductions in either group indicating a quantitatively minor role for the sympathetics in regulation of total cerebral blood flow in cats.
Influence of Fixation on Physiological Properties of Frog Gastric Mucosa
Authors: Helander Herbert F. , Rehm Warren S. , Sanders Sue S.
Published: December 2008

Functional properties of the in vitro frog gastric mucosa were studied during fixation with glutaraldehyde (G4) or OsO4. The acid secretory rate dropped quickly and was completely absolished within 5–15 min. When fixative was added to either the serosal or mucosal surface of the mucosa the potential difference decreased rapidly within the first minute and frequently became temporarily inverted. The electrical resistance changes almost always included an initial drop. With GA added to either side and with OsO4 added to the serosal side the resistance then rose to values above the controls, again returning to very low values after intervals usually between 15 min and 2 h. With OsO4 added to the mucosal side the resistance decreased rapidly to low levels and did not recover. The selective permeability of the nutrient membrane of K+ over Na‐ was decreased within 5 to 10 min, but was not abolished until about 35 min after the addition of the fixatives, at which time the mucosal resistance was still high. It is concluded that the ion‐conducting pathways in the plasma membranes are greatly changed by the fixatives, which should be taken into consideration when interpreting electron micro‐graphs.
Noradrenaline Depletion in the Kidney Vessels in Experimental Ascites
Authors: Penttilä Antti , Tallqvist Gustav
Published: December 2008

Noradrenaline depletion in experimental ascites originally observed by the authors could hypothetically be attributed to the ascites formation or to the tumour by which the ascites wits induced. Therefore mice were injected intraperitoneally or subcutaneously with Ehrlich ascites carcinoma. Noradrenaline was assayed histochemically and biochemically in the kidney at various times after injection. Mice with intraperitoneal tumour and ascites had significantly less noradrenaline than controls both histochemically and biochemically. Mice with subcutaneous tumour (without ascites) had depletion that was significant, by biochemical tests, only on the iifth and seventh days but was not detectable histochemically. It is concluded that noradrenaline depletion seems to be associated with the tumour growth per se but more particularly with ascites formation.
Renal Medullary Red Cell and Plasma Flow as Studied with Labelled Indicators and Internal Detection
Authors: Wolgast Mats
Published: December 2008

Regional renal medullary red cell and plasma flow has been investigated on 8 dogs using 32‐P labelled red cells and plasma and detection with small needle‐shaped semiconductor detectors put into the parenchyma. The transit times were determined by dividing the area with the height of the indicator‐dilution curves obtained after slug injections of alternatively labelled red cells and labelled plasma into the renal artery. Regional red cell volume was obtained from intrarenal equilibrium activity. The plasma volumes relative to the red cell volumes was determined by comparing the areas of the two indicator‐dilution curves. Whole blood flow was then estimated at 2 ml/min and g tissue in the outer zone continuously decreasing to values around 0.5 ml/rnin and g tissue in the inner parts of the inner zone. The hematocrit in vasa recta blood (denoting the ratio between the flow of red cells to the flow of whole blood) was in the outer zone 85% of that in arterial blood, successively decreasing to about 50% in the inner parts of the renal medulla.
Proximal Luminal Diameters and Cell Volume in Rats Anesthetized with Inactin and Amytal
Authors: Elmer M. , ØTergaard KRISTENSEN L. , Leyssac P. P.
Published: December 2008

Luminal diameters and cellular area oi cross‐sectioned, superficial proximal convolutions were measured in freeze‐dryed cryo‐sections of normal, non‐diuretic rat kidneys instantly frozen with liquid nitrogen at the end of clearance‐and micropuncture experiments. Two series were investigated; in one series rats were anesthetized with the thiobarbiturate Inactin; in the other series the oxybarbiturate Amytal was used as anesthetic; all other factors were equal. In rats anesthetized with Amytal proximal luminal radius was about 14 μm independent of the inulin clearance (ClIN) over a range between 0.57 and 1.61 ml · min‐1· g KW‐1. Proximal cellular volume, as estimated from the cross‐sectional area, was also independent of the clearance value. In the Inactin series proximal luminal radius correlated with ClIN(p ˜ 0.018) The luminal radius was depressed from a value of 14.5 μm at a ClINabout 1.40 ml · min‐1g KW‐1to 12.0 μm at a ClINof about 0.50 ml · min‐1g KW‐1, a value significantly less than that of the Amytal series. Although the cross‐sectional cellular area tended to increase at low clearance values in the Inactin series, the increase was not statistically significant. The data do not exclude, however, the existence of an inverse relationship between cellular volume and ClIN
Effects of Insulin and Testosterone on Glycogen Synthesis and Glycogen Synthetase Activity in Rat Levator Ani Muscle
Authors: Adolfsson Sten
Published: December 2008

The temporal relationships for hormonal stimulation of glycogen synthesis are not clarified. In the present study glycogen synthesis and the activation of the rate‐limiting glycogen synthetase enzyme (EC 2.4.1.11) were investigated in levator ani muscles from prepubertal male rats during insulin stimulation in vitro for 5–240 min and testosterone stimulation in vivo for 4–36 h. For both hormones, glycogen content was gradually increased to a level of 8.5–9.0 mglg tissue. An activation of the synthetase enzyme by means of an increase of its I‐form was found after only 5 min of insulin stimulation. The increase in I‐form was continuously reduced and reached control level after 150 min of incubation. For testosterone, the I‐form was steadily increased 6–16 h after injection of the hormone. The incorporation of glucose‐14C into glycogen was increased in both studies even when the I‐form was no longer increased. The level of glucose‐6‐phosphate was aiso measured and the results suggest an activation of the synthetase enzyme by changes in the concentration of this metabolite during hormonal stimulation. It is concluded that the length of stimulation is of importance for the stimulation of muscle glycogen synthesis by insulin and testosterone.
Effects of Severe Systemic Hypoxia on Myocardial Energy Metabolism
Authors: Fellenius E. , Samuelsson R.
Published: December 2008

By the use of freeze‐clamp technique, simultaneous tissue samples were taken from the right atrial and the right ventricular muscle of the working heart in anesthetized dogs during a hypoxia‐recovery cycle consisting of 4 min of severe, systemic hypoxia followed by a period of recovery of equal duration. In order to study the energy metabolism of the two parts of the heart, the tissue samples were analyzed with respect to their content of creatinephosphate, adenine nucleotides, pyruvate, lactate, dihydroxyacetonephosphate, α‐glycerophosphate and malate. During aerobic, controlled ventilation, the ventricular tissue was found to contain higher concentrations of high‐energy phosphate compounds than the atrial tissue. During the period of hypoxia, the atrial and ventricular tissue contents of creatinephosphate were reduced to about 10% whereas ATP was reduced merely to about 70% of the control values. The rate of the anaerobic glycolysis was found to proceed more rapidly in the ventricular muscle, thereby indicating a higher rate of energy metabolism, than in the atrial muscle.
Effects of Severe Systemic Hypoxia on Myocardial Excitation
Authors: Samuelsson R.
Published: December 2008

In anesthetized dogs, monophasic action potentials from the right atrium and the right ventricle were recorded by an intracardiac suction electrode technique, together with the electrocardiogram (standard lead II). The animals were subjected by ventilation with 100% nitrogen to periods of severe, systemic hypoxia. The separate effects of myocardial oxygen deficiency and increased autonomic influence on the myocardial excitation were studied, using animals with (1) intact autonomic innervation of the heart, (2) parasympathetically denervated hearts and (3) parasympathetically and sympathetically denervated hearts. During severe, systemic hypoxia the parasympathetic influence predominated over the sympathetic and induced a pronounced shortening of the duration of the atrial monophasic action potential whereas the increased sympathetic activity induced no alteration of the duration of the ventricular monophasic action potential. The myocardial oxygen deficiency induced a shortening of the duration of the atrial monophasic action potential which appeared earlier than that of the duration of the ventricular monophasic action potential when the autonomic influences were excluded. During the recovery from myocardial oxygen deficiency, the duration of the atrial monophasic action potential was normalized earlier than that of the ventricular monophasic action potential. Pronounced ST‐segment and T‐wave elevations in the ECG were in general recorded when the period of severe, systemic hypoxia exceeded 2 min.
Vago‐vagal Gastro‐gastric Relaxation in the Cat
Authors: Abrahamsson Hasse , Jansson Gunnar
Published: December 2008

In anesthetized cats electric afferent stimulation of nerve branches emanating from the gastric corpus region promptly elicited reflex gastric relaxation. The response was not blocked by atropine, guanethidine or cervical spinal cord transection but was abolished by cervical vagotomy, showing that the vagal “relaxatory” fibres to the stomach mediate this reflex effect. Transient distension of the stomach produced a long‐lasting gastric relaxation with similar characteristics as that obtained by the mentioned afferent electric stimulation. By vagal blockade in atropinized cats it was shown that the vagal nerves exerted no or only slight relaxatory effects if the stomach was only slightly filled, hut then had a profound relaxatory effect when the stomach was moderately or greatly filled. It is concluded that a vago‐vagal gastro‐gastric relaxatory reflex exists where the vagal non‐adrenergic relaxatory fibres serve as the efferent link. The reflex can be activated from gastric mechanoreceptors responding to distension and is suggested to be involved in the regulation of receptive relaxation in gastric filling.
Effect of Histamine Loading on the Metabolism of 14C‐Histarnine, Administered Intravenously or Orally, in Domestic Animals (Goat and Pig)
Authors: Eliassen Knut Arnet
Published: December 2008

Isotope dilution technique has been used to examine the effect of histamine loading on the metabolism of orally and parenterally administered 14C‐histamine. 3% and 45% of the radio‐activity was recovered in the urine of goats and pigs, respectively, when only 14C‐histamine was given orally. In goats the radioactivity was mostly present as unidentified metabolites. In goats, oral loading with 0.9–1.2 g histamine increased the fraction excreted as ImAA on an average from about 5% to 34% whereas the amount of unidentified metabolites was reduced. Independent of the dose given about 30% of orally administered radioactivity was excreted as 14CO2. In pigs a moderate increase in 14‐imidazoleacetic acid was observed after oral histamine loading. In contrast to i.v. administered histamine, orally administered histamine was partly excreted as 14C‐conjugated histamine in the pig. In pigs and goats neither oral nor i.v. histamine loading seemed to have any effect on the fraction excreted in urine as 14C‐histamine. The only significant effect on histamine catabolism of i.v. loading of histamine was a reduction of the fraction excreted as 14C‐1.4‐MeHi. However, such loading of histamine in pigs seems to liberate histamine and/or histamine metabolites, since the increments in urinary histamine and histamine metaboiites exceeded the administered dose.
On the Elimination of Transfused Heparin‐Induced Diamine Oxidase (DAO) Activity in Rabbits
Authors: Hansson R. , Thysell H.
Published: December 2008

Lymph or blood plasma, rich in diamine oxidase (DAO; EC 1.4.3.6.) activity was obtained from donor rabbits, after i.v. injection of heparin. The lymph or, after heparin neutralization, the blood serum was injected into recipient rabbits, and the elimination of the transfused DAO activity was studied. Analogously to earlier findings in man, the elimination rate of transfused DAO activity was several times more rapid than is indicated by the apparent rate of return to normal levels in rabbits, after heparin‐induced increase in blood plasma DAO activity. Furthermore, our findings indicate the possibility of 2 different components of the elimination of transfused postheparin rabbit DAO activity, somewhat contrasting to the findings in man.
Effect of Organ Removal or Damage on the Heparin‐Induced Diamine Oxidase (DAO) Response in Rat and Rabbit
Authors: Hansson R. , Thysell H.
Published: December 2008

The postheparin DAO increase in blood plasma has been shown to depend on intact intestines in rat and rabbit. Our findings indicate, however, that sources of mobilizable DAO may be found also outside the small intestine in these species. In the rat, after partial portal stricture for a week. hepatectomy was followed by an intense and rather sustained post‐heparin DAO increase, as compared to normal, or shamoperated, rats.
The Liver‐like Anion Transport System in Rabbit Kidney, Uvea and Choroid Plexus. I. Selectivity of Some Inhibitors, Direction of Transport, Possible Physiological Substrates
Authors: Bárány Ernst H.
Published: December 2008

Accumulation of o‐iodohippurate and iodipamidein vitrooccurs by 2 overlapping systems, the liver‐like L‐, and H‐, the classical PAH‐transporting one. Selectivity of competitors is compared by measuring depression of simultaneous uptake of o‐iodohippurate and iodipamide. Results (kidney cortex): o‐Iodohippurate has similar H‐selectivity as hippurate while iodipamide is much more L‐selective than its non‐iodinated parent. Ioglycamic acid is at least as L‐selective as iodipamide. Rabbit bladder bile is L‐selective, rabbit and human urine H‐selective. Probenecid is somewhat H‐selective, its diethyl homologue more H‐selective, its dibutyl homologue more L‐selective. Phenol red, furosemide, ethacrynic acid, sulfobromophthalein, phenolphthalein and iopanoic acid are rather unselective. Selectivity of probenecid, hippurate and iodipamide is not influenced by incubation time. Cephaloridinein vitrois somewhat H‐selective but inhibits both systems in kidney, choroid plexus and uvea.In vivo200 mg/kg causes tubular damage which depresses the H‐more than the L‐system. Choroid plexus and ciliary processes are undamaged. The two systems L‐and H‐seem to have the same direction of transport, from aqueous humour and CSF to the blood and from the blood into the urine. The H‐system mainly deals with candidates for urinary and the L‐system with candidates for biliary excretion.
Vomiting and Reflex Vagal Relaxation of the Stomach Elicited from Heart Receptors in the Cat
Authors: Abrahamsson Hasse , Thorén Peter
Published: December 2008

The effect of afferent stimulation of the vagal cardiac nerves on gastric motility, heart rate and arterial blood pressure was studied in cats. Electric stimulation of the right cardiac nerve elicited, beside bradycardia and hypotension, a prompt and pronounced gastric relaxation and, after a latency, somatomotor vomiting movements.—Frequency‐response curves showed maximal circulatory effects already around 6 Hz while the curve for gastric relaxatory response was less steep. Frequent retching was observed at stimulations of 10 Hz or more.—The gastric relaxation upon afferent cardiac nerve stimulation was abolished by sectioning the right vagus caudad to the cardiac nerve and the left vagus in the neck, showing that vagal efferents mediated the gastric relaxation. The gastric response persisted after atropine and guanethidine ad was mimicked by reflex activation of the vagal “relaxatory” fibres to the stomach by esophageal distension. Intrapericardial nicotine and coronary artery occlusion also activated the described gastric reflex.—It is concluded that vomiting can be elicited by thin vagal cardiac afferents, probably of ventricular origin. Gastric relaxation, mediated by the vagal non‐adrenergic relaxatory fibres, constitute part of this vomiting response, as when vomiting is induced by apomorphine.
Recurrent Inhibition from Motor Axon Collaterals of Ventral Spinocerebellar Tract Neurones
Authors: Lindström S. , Schomburg E. D.
Published: December 2008

Recurrent inhibition from motor axon collaterals was searched for in intracellularly recorded ventral spinocerebellar tract (VSCT) neurones in the cat. A small proportion of the investigated cells received inhibition on antidromic stimulation of ventral roots. The IPSP was evoked by a‐fibres, had a segmental latency indicating a disynaptic linkage from motor axon collaterals and a duration of about 50 ms. The inhibited cells received monosynaptic excitation from group Ia muscle spindle afferents. The inhibition could be demonstrated also on the VSCT mass discharge evoked by stimulation of Ia afferents. The ventral roots, giving rise to the inhibition in a given VSCT cell, were the same as the ventral roots which give recurrent inhibition in a‐motoneurones and Ia inhibitory interneurones excited by Ia afferents of the same muscle as the VSCT cell. The results indicate that Renshaw cells, terminating on a‐motoneurones and Ia inhibitory interneurones, also send collaterals to some VSCT neurones. This finding strongly supports the idea that the VSCT relays information about the transmission in intemeuronal inhibitory reflex pathways to motoneurones (Lundberg 1971).
Drug Effects on Pre‐and Post‐branchial Blood Pressure and Heart Rate in a Free‐swimming Marine Teleost, Gadus morhua1
Authors: Helgason Sigurdur St. , Nilsson Stefan
Published: December 2008

Drug effects on pre‐and post‐branchial blood pressure and heart rate have been simultaneously and continuously registrated in free‐swimming cod(Gadus morhua).Adrenaline, noradrenaline and phenylephrine increased blood pressure, presumably by increasing systemic vascular resistance by alpha adrenergic stimulation. The heart rate was decreased by the same drugs, obviously by a baro‐receptor reflex, with the efferent inhibitory cholinergic fibres running in the vagus nerve. Yohimbine decreased the blood pressure and blocked the effect of adrenaline. The drop in blood pressure may be due to blockade of a normally acting vaso‐constrictor effect on the systemic vessels. Pre‐and post‐branchial blood pressure was reduced by isoprenaline, and this effect was reversed by propranolol, suggesting presence of adrenergic beta‐receptors in the systemic vascular bed. Propranolol also caused a drop in heart rate and post‐branchial blood pressure, while the pre‐branchial blood pressure was increased. This again could be due to abolishment of a normally acting adrenergic influence on the heart and branchial vessels.
Effect of Training with Eccentric Muscle Contractions on Skeletal Muscle Metabolites
Authors: Bonde‐Petersen Flemming , Henriksson Jan , Knuttgen Howard G.
Published: December 2008

The effect of training with eccentric contractions on skeletal muscle metabolism was in‐vestigated with human subjects engaged in cycling exercise. Experiments involving extended (30 min) exercise at high relative intensities were performed before and after a 5‐week period of training (25–30 min per day, 22 days). Muscle biopsies (lateral portion of m. quadriceps femoris) were taken at rest, after 4 min exercise, and termination of exercise. Expired air was collected periodically for determination of respiratory exchange. Vo 2 and heart rate were lowered by training (e.g., after 26 min of exercise: from an average of 0.96 to 0.74 1 × m‐l and 115 to 96 beats × min‐1, respectively). Muscle metabolite concentration evidenced no significant changes but respiratory exchange ratio (R) was decreased (after 10 and 26 min, from an average of 0.85 to 0.80 in both instances). Metabolic determinations offered no explanation for the lowered 02 cost of exercise nor evidence for or against the hypothesis that the muscles utilize the mechanical energy recived during eccentric exercise.
Circulatory Control via Vagal Afferents VI. The bleeding bradycardia in the rat, its elicitation and relation to the release of vasopressin
Authors: SJÖSTRAND TORGNY
Published: December 2008

Sjöstrand, T. Circulatory control via vagal afferents. VI. The bleeding bradycardia in the rat, its elicitation and relation to the release of vasopressin. Acta physiol. scand. 1973. 89. 39–50.

Bradycardia appears regularly in Sprague‐Dawley rats on arterial hemorrhage. It is usually preceded by an increase of the heart rate of varying duration. On an average the bradycardia starts 21s after the fall in arterial pressure. On reinfusion the bradycardia disappears during 10–20 min following a varying course. Compression of the inferior caval vein provokes bradycardia which appears and disappears similarly but starts earlier in relation to the pressure fall. If blood or saline is intravenously infused simultaneously with the hemorrhage, the bradycardia starts later and is less pronounced in relation to the fall in arterial pressure. The bradycardia is inhibited by hypophysectomy, hydration and infusion of small amounts of ethyl alcohol through the carotid artery. A similar bradycardia may be provoked by intra‐carotid infusion of vasopressin at maintained arterial pressure.

It is concluded that the bleeding bradycardia is elicited by receptors on the low pressure side stimulated by a decrease of the venous return or central blood volume and is a part of a reflex control of the blood volume and distribution. The release of vasopressin is stimulated through vagal afferents and, by local transmission, exerts an excitatory effect on the depressor area in the hypothalamus. The significance of the deduced vasopressin releasing reflex under normal and pathological conditions is discussed.
Ventilation at Transition from Rest to Exercise
Authors: Asmussen By Erling
Published: December 2008

Asmussen., E. Ventilation at transition from rest to exercise. Acta physiol. scand. 1973. 89. 68–78.

The “fast neurogenic component” of the increase in ventilation taking place at the transition from rest to exercise was studied by a breath‐to‐breath analysis of VE. AND PACO2 The questions investigated were: 1) Is the “fast neurogenic component” correlated to the intensity of the exercise: 2) Is it due to a specific work stimulus to the respiratory center, or caused by an increased sensitivity to existing chemical stimuli? 3) Is it related to movements or to the mechanical tensions in the working muscles? The results showed: 1) There is a rough correlation between the “fast neurogenic component” and the power of the bicycle‐work performed. 2) If the chemical stimuli, expressed by PACO2 AND PAo2, are eliminated by voluntary hyperventilation in pure oxygen, the “fast neurogenic component” disappears. With one or both of these stimuli present, exercise augments their effect. 3) Transition from rest to static exercise (no movements) is not accompanied by a “fast neurogenic component”. Rhythmic movements cause a rapid increase in VE, related to the frequency of movement. Sudden loacling of the bicycle during no‐load pedalling causes a relatively slower further increase in ventilation, apparently independent of the force exerted on the pedals, but related to the power of work. It is suggested that some metabolic factor in the working muscles is responsible for this part of the “fast neurogenic component”.
The Count of Mast Cells, Tissue Eosinophils, and Epithelial Mitoses of Rat Gastrointestinal Mucosa after Aspirin Treatment
Authors: RÄSÄNEN Toimi , Taskinen Eero
Published: December 2008

Rasanen, T. AND E. Taskinen. The count of mast cells, tissue eosinophils, and epithelial mitoses of rat gastrointestinal mucosa after aspirin treatment. Acta, physiol. scand. 1973.89. 182–186.

Mucosal mast cells, tissue eosinophils and epithelial mitoses were counted in the gastrointestinal tract of rats given 1, 3 and 5 times 10 nig of aspirin in 5 ml of water at 12 h intervals by cannulation into the stomach. The mast cell count of the gastric and duodenal mucosa ot rats receiving aspirin fell sharply. No significant change was observed in tissue eosinophilia. The mitotic count in the epithelium of stomach declined clearly, but no decrease occurred in the mitoses of the epithelial cells in the mucosa of the duodenum, jejunum and colon. The results seem to indicate that the injurious action of aspirin is transmitted so that the gastric mucosal mast cells possibly participate in it directly: the heparin contained in the mast cell granules inhibits in the phase of liberation the mitotic activity, especially in the gastric epithelium, and the blood coagulation mechanism locally. The histamine and liliydroxy‐tryptamine liberation associated with the release of heparin results in the stimulation of secretion and in vascular reactions of the gastric mucosa.
Growth Hormone and Cortisol Secretion in Man
Authors: Laisi U. , Leisti S. , Leppaluoto J. , Lumio J. , Partanen J. , Virkkunen P.
Published: December 2008

Laisi, U., S. Leisti, J. Leppäluoto, J. Lumio, J. Partanenand P. Virkkunen. Growth hormone and Cortisol secretion in man. Acta physiol. scand. 1973. 89. 192–197.

In 4 healthy resting males blood was collected through indwelled catheters at 1–3 min intervals and EEG recorded in a sound‐shielded anechoic environment for 30 min (expt. 1). The iminunorcactive plasma growth hormone was at high concentration (10–33 ng/ml) and was secreted in 3 significant bursts in one subject, but was low (0–4 ng/ml) in 3 other subjects. The plasma Cortisol, measured by a fluorometric method, was at low and constant level (mean ±S.D. = 8.9±1.5 μg/100 ml). The EEG vigilance fluctuated between wakefulness and real sleep. The plasma growth hormone concentration tended to be high at wakeful stages and low at sleep stages. There was no correlation between vigilance and plasma Cortisol level. In the middle of the following experiment (expt. 2) a painful faradic current was applied to the forearm for 10 s and blood was collected as in expt. 1. The plasma Cortisol level before the painful stimulus was significantly increased (12.3±4.6 /yg/100 nil) and did not change after the stimulus, in spite of the clear increase of vigilance. The high prc‐stimulus level of plasma Cortisol is evidently due to anticipatory mechanisms. We conclude that growth hormone is secreted in bursts which may last as short as 5 min and that the increase of vigilance could trigger the secretion of growth hormone but not that of Cortisol.
The Effect of Reduced Perfusion Pressure and Regional Sympathetic Vasoconstrictor Activation on the Rate of Absorption of85Kr from the Small Intestine of the Cat
Authors: Svanvik Joar
Published: December 2008

Svanvik, J.The effect of reduced perfusion pressure and regional sympathetic vasoconstrictor activation on the rate of absorption of85Kr from the small intestine of the cat.Acta physiol. scand. 1973.89.239–248.

The absorption from the small intestinal lumen to the intestinal blood stream of an easily diffusable substance,85Kr, was studied in the cat during different hemodynamic conditions. When reducing arterial inflow pressure to the intestine from about 100 to 30 mm Hg the absorption rate was reduced in proportion to the venous outflow although an earlier study demonstrated an almost unchanged villous blood flow during corresponding experimental conditions. Also when raising the venous outflow pressure absorption rate decreased in proportion to venous outflow while during neurogenic reductions of intestinal blood flow the absorption rate was not significantly changed. The results are discussed mainly with regard to the intestinal mucosal hemodynamics and countercurrent exchanger.
Intrarenal Distribution of Glomerular Filtration in Conscious Rats during Isotonic Saline Infusion
Authors: Clausen By Gunnar , Tyssebotn Ingvald
Published: December 2008

Clausen, G. and I. Tyssebotn. Intrarenal distribution of glomerular filtration in conscious rats during isotonic saline infusion. Acta physiol. scand. 1973. 89. 289–295.

Relative individual glomerular filtration rate (gfr) of juxtamedullar (JM) and superficial (S) nephrons was determined in conscious rats by the 14C ferrocyanide technique. Isotonic saline infused at 250 μd/min × 100 g b.w. for about 60 min reduced fractional Na‐reabsorption by 11 % with no significant change in inulin clearance. The S gfr averaged 90 % of JM gfr both in control and saline loaded animals, but with less scatter in the latter group. Thus the natriuresis produced by acute i.v. isotonic saline loading in conscious rats is not caused by redistribution of filtrate.

Extracellular volume expansion Individual nephron filtrate Saline loading

Sodium excretion 14C Sodium ferrocyanide
The Distribution of Absorbed 3H‐palmitic Acid in the Intestinal Villi of the Cat during Various Circulatory Conditions
Authors: Jodal Mats , Lundgren Ove
Published: December 2008

Jodal, M. and O. Lunduren. The distribution of absorbed ‐3H‐palmitic acid in the intestinal villi of the cat during various circulatory conditions. Acta physiol. scand. 1973. 89. 318–326

The distribution of absorbed 3H‐palmitic acid within the villous tissue was investigated by determining the amount of radioactivity per unit weight tissue protein in 40 ‐60μm thick tissue slices cut perpendicular to the long axis of the villi. In most experiments a bile solution containing the tracer was incubated in the intestinal lumen for 1 min during in vivo conditions. At “resting” blood flow a steep gradient of radioactivity along the villous length was observed, the highest amount of tracer being found at the tip. This gradient was less steep if the experiments were performed during total intestinal ischemia. The tissue content of “H‐palmitic acid could be markedly decreased by intense vasodilatation or by placing a 7 % albumin solution on the “luminal” surface of the intestinal epithelial cells, after removing the bile solution containing the tracer. The serum albumin, continuously circulating at the “tissue” surface of the epithelial cells, was far less efficient in lowering tissue content of radioactivity. The results are discussed with regard to present concepts of lipid absorption. It is proposed that the results of the present investigation are explained by a “trapping” of the palmitic acid in the intestinal countercurrent exchanger efficiently hindering net blood absorption of the fatty acid.
Studies on the in Vivo Absorption of Butyric Acid in the Small Intestine of the Cat
Authors: Jodal Mats , Lundgren Ove
Published: December 2008

Jodal, M. and O. Lundgren. Studies on the in vivo absorption of butyric acid in the small intestine of the cat. Acta physiol. scand. 1973. 89. 327–333.

The effect of the intestinal countercurrent exchanger on the absorption of short chain fatty acids (SFA; 14C‐butyric and 3H‐propionic acid) was studied in vivo by autoradiography and by using a technique which allowed determination of the tracer concentration along the villous length. A modest concentration gradient from villous tip to villous base was found at “resting” blood flow, the gradient being abolished by maximal vasodilatation or by intestinal ischemia. Furthermore, the tissue content of SFA was largely uneffected by changes in intestinal blood flow. The observations suggest that SFA are far less effected by the countercurrent exchanger than long chain fatty acids. No evidence was provided for the existence of an “active” absorptive mechanism of SFA.
Effect of Body Temperature on Steady State Ventilation and Metabolism in Exercise
Authors: Petersen Ebbe Strange , Vejby‐Christensen Hans
Published: December 2008

Petersen, E. S. and H. Vejby‐Christensen. Effect of body temperature on steady state ventilation and metabolism in exercise. Acta physiol. scand. 1073. 89. 342–351.

Four healthy subjects were studied at rest and during steady slate of work at normal room and body temperature, and at elevated body temperature (38.5o C) in a climatic chamber. Ventilation, oxygen uptake, carbon dioxide elimination, heart rate, and blood lactate and pyruvate concentrations were measured. At equal work loads ventilation was not different, although respiratory rate was consistently higher and tidal volume lower at elevated temperature. Oxygen uptake was lower, and the ventilatory equivalent therefore higher in hyperthermia than in normothermia. Blood lactate concentration was higher both at rest and at all work loads indicating an increased anaerobic energy yield in hyperthermia. The study indicates the existence of a temperature threshold near 38o C, above which a relative hyperventilation is seen. The observed hyperventilation is hardly caused by changes in the [H+]‐stimulus, and it is suggested that hyperthermia per se or through interaction with other stimuli might constitute the additional ventilatory drive.
Thyroid Function Studies in Normal and Gold‐Exposed Rabbits Using 125I
Authors: Carlson Loren D. , Roohk H. Vernon , Wilson Ove
Published: December 2008

Carlson, L. D., H. V. Roohk and O. Wilson. Thyroid function studies in normal and cold‐exposed rabbits using 125I. Acta physiol. scand. 1973. 89. 359–373.

Normal uptake and retention of 125I in thyroid was measured for 2–17 weeks in rabbits, and the effect of TSH, T4, acute and extended cold exposure was studied. There were marked interindividual variations in maximum uptake (mean 7 %, range 2.5–18 %), in time to peak (12–72 h), in the slope of the retention curve, and in changes in release rate. Repeated doses gave different maximum uptakes, but time to peak and form of retention curve remained essentially the same for each animal. The mean biological half‐life for a 35‐day period was 12 days for 8 rabbits; the initial half‐life of around 9 days for the 1st week gradually increased to around 16 days during the last 3 weeks. This change suggests a shift of the labelled iodine into thyroidal compartments with slower turnover rates. Analysis of the multiexponential slope showed that the release phases for all rabbit were satisfactorily represented operationally by two exponentials. The mean values for these corresponded to biological half‐lives of 6.4 and 21.1 days. Neither acute and more severe (‐3o and 6o C for 50 h) nor moderate, extended cold (9–10o C for 7–16 days) had the slightest influence on the loss of radioiodine from the thyroid, which nevertheless responded to small doses of TSH.